Possible Source of Arsenic Contamination Agrochemical?
- Surface Water Contamination
- 1.1 Surface and near-surface biogeochemical processes mobilize arsenic in Bangladesh-New
- Deep Aquifers not contaminated
- The World Bank
- Irrigation System in Bangladesh
- Destruction of Traditional Methods
- Soil Erosion
- Hazardous Waste
- Arsenic poisoning from cow-dung fuel
- Indirect Disposal of Hazardous Waste
- Management of Agrochemical
- Ban toxic pesticides, demands rally,
Chapai Nawabganj: worst arsenic affected areas of Bangladesh
- Sourcing Bangladesh's arsenic
- Anthropogenic influences on groundwater arsenic
The British Geological Survey (BGS), the UK's most prestigious hydrology centre, carried out the studies on behalf of the Bangladesh Government in the mid-1980s and early-1990s, more than six years before arsenic was shown to be the cause of the mystery illnesses affecting millions of people. S. Connor and F. Pearce (19.01.01) describes in the Independent News, U.K., "British scientists failed to detect dangerous levels of arsenic in the supply of drinking water implicated in the biggest mass poisoning in history. Two studies of ground water quality in Bangladesh carried out by British hydrologists failed to monitor natural arsenic levels even though the testing was suggested in voluntary guidelines drawn up by the World Health Organisation. If one really wanted to be charitable to the BGS, you'd excuse them for not finding it the first time, but failing to look a second time appears to be inexcusable."
The sources of arsenic contamination is not of a natural origin as presumed by the British Geological Survey and others. Comparing Marshall Sandstone of south-eastern Michigan the source is possibly known, as arsenic was found in sandstone range from 4-140 mg/kg and in shale dominated sections between 40- 310 mg/kg – possibly the same formation overlain by the last glacial till (Kolker et al., 1998).
Helen Sewell of BBC Science . Oct 6, 1999 reports Fertilisers used in Bangladesh may have put millions of lives at risk, according to a new study by scientists in India. The danger comes from the poison arsenic, which is polluting supplies of drinking water. Two government departments in Bangladesh and four international organisations are facing legal proceedings for allegedly failing to protect the population.
Dr. Shaha's survey in the West Bengal that the lag time for the appearance of arsenic disease is two to five years and according to Allen Smith and others it is about 10 years. People of Bangladesh and West Bengal have similar physical conditions, their food habits and intake of water are similar. If groundwater arsenic poisoning was present in Bangladesh prior to 1975, then millions of tube well water users between 1965 and 1975 would have certainly been poisoned by arsenic. Ten years is an adequate time for the appearance of arsenic diseases on the people of Bangladesh. The youngest arsenic poisoned patient detected in Bangladesh was Baby Jamil, an eighteen months old infant. If knowledgeable, experienced, and dedicated professionals survey arsenic poisoned patients in the community, they will find none of the people were poisoned prior to 1975. Arsenic-poisoned patients were first discovered in Bangladesh in the early 1994 and in West Bengal in the early 1985. The historical medical evidence supports a recent origin for the mobilization of arsenic into the groundwater of Bangladesh and West Bengal of India.
Those scientists who have been promoting that the arsenic disaster in Bangladesh is a natural disaster, and that the poisoning has been present for thousands of years and that Oxyhydroxide reduction is the principal cause for releasing arsenic into groundwater are mainly based on incorrect, inadequate as well as false data.
The UK/DFID statement on the age of the arsenic poisoning in groundwater in Bangladesh contradicts the historical medical evidences.
World's top 10 most polluted places Where toxic pollution and human habitation collide with devastating effects
1. Sumqayit, Azerbaijan—This area gained the dubious distinction of landing atop the Blacksmith Institute’s list of the world’s most polluted sites. Yet another heir to the toxic legacy of Soviet industry, this city of 275,000 bears heavy metal, oil and chemical contamination from its days as a center of chemical production. As a result, locals suffer cancer rates 22 to 51 percent higher than their countrymen, and their children suffer from a host of genetic defects, ranging from mental retardation to bone disease. “As much as 120,000 tons of harmful emissions were released on an annual basis, including mercury,” says Richard Fuller, founder of Blacksmith, an environmental health organization based in New York City. “There are huge untreated dumps of industrial sludge.” 2. Chernobyl, Ukraine—The fallout from the world’s worst nuclear power accident continues to accumulate, affecting as many as 5.5 million people and leading to a sharp rise in thyroid cancer. The incident has also blighted the economic prospects of surrounding areas and nations. 3. DzerzHinsk, Russia—The 300,000 residents of this center of cold war chemical manufacturing have one of the lowest life expectancies in the world thanks to waste injected directly into the ground. “Average life expectancy is roughly 45 years,” says Stephan Robinson, a director at Green Cross Switzerland, an environmental group that collaborated on the report. “Fifteen to 20 years less than the Russian average and about half a Westerner’s.” 4. Kabwe, Zambia—The second largest city in this southern African country was home to one of the world’s largest lead smelters until 1994. As a result of that industry, the entire city is contaminated with the heavy metal, which can cause brain and nerve damage in children and fetuses. 5. La Oroya, Peru—Although this is one of the smallest communities on the list (population 35,000), it is also one of the most heavily polluted because of extensive lead, copper and zinc mining by the U.S.–based Doe Run mining company. 6. Linfen, China—A city in the heart of China’s coal region in Shanxi Province, Linfen is home to three million inhabitants, who choke on dust and air pollution and drink arsenic that leaches from the fossil fuel. 7. Norilsk, Russia—This city above the Arctic Circle contains the world’s largest metal-smelting complex and some of the planet’s worst smog. “There is no living piece of grass or shrub within 30 kilometers of the city,” Fuller says. “Contamination [with heavy metals] has been found as much as 60 kilometers away.” 8. Sukinda, India—Home to one of the world’s biggest chromite mines—chromite makes steel stainless, among other uses—and 2.6 million people. The waters of this valley contain carcinogenic hexavalent chromium compounds courtesy of 30 million tons of waste rock lining the Brahmani River. 9. Tianying, China—The center of Chinese lead production, this town of 160,000 has lead concentrations in its air and soil that are 8.5 to 10 times those of the national health standards. The concentrations of lead dusting the local crops are 24 times too high. 10. Vapi, India—This town at the end of India’s industrial belt in the state of Gujarat houses the dumped remnant waste of more than 1,000 manufacturers, including petrochemicals, pesticides, pharmaceuticals and other chemicals. “The companies treat wastewater and get most of the muck out,” says David Hanrahan, Blacksmith’s London-based director of global operations. “But there’s nowhere to put the muck, so it ends up getting dumped.” (Source:http://www.scientificamerican.com, December 3, 2009}
During 1983 and 1987 Dr. K.C. Shaha, Professor of Dermatology (retired) of School of Tropical Medicine, Calcutta conducted surveys in the seven districts of west Bengal of India. In 1983 Dr.Shaha identified patients poisoned by arsenic who had been drinking tubewell water with concentration of arsenic ranged from (0.06-1.25) PPM and a mean concentration of 0.32 PPM.
If groundwater arsenic contamination had been present for thousands of years, as suggested by the UK report, then both shallow hand-dug wells and tubewells would extract arsenic contaminated water and would have impacted water users with arsenic poisoning before 1975.
During the 1965 to 1975 period about 4.5 million wells were installed and millions of children and infants drank water from these wells. Prior to 1975 there is no evidence that arsenic poisoning had affected people in Bangladesh, therefore, it appears that the groundwater arsenic poisoning in Bangladesh is a recent environmental episode and began after 1975.. Therefore, the UK/DFID statement on the age of groundwater arsenic poisoning in Bangladesh is not based on scientific facts but rather it is based on speculation ( Meer T. Husain, Environmental Geologist, Kansas Department of Health And Environment, Kansas, USA.(2000) .
We have been coducting research in order to find the source and the cause of the groundwater arsenic poisoning in Bangladesh since 1998. We analyzed the investigative reports of DPHE/BGS investigators, McArthur et.al., Aggarwal et.al., Bhattacharya et.al., Shafiqul Islam & Feroz Ahmed et.al. and others who have been suggesting that the groundwater arsenic poisoning in Bangladesh is a natural disaster, that the poisoning has been present in the groundwater of Bangladesh for thousands of years and that the oxyhydroxide reduction is the principal mechanism for releasing arsenic into groundwater.
Our research findings have revealed that these investigators have presented an incorrect and misleading theory to the people of Bangladesh and the scientific community, based on incorrect and inadequate data.
Geologists, hydrologists and hydrogeologists who have had experience in dealing with investigation, remediation and monitoring of soil and groundwater contamination projects, protection of water resources, and protection of public health and environment from the soil and the groundwater contamination problems, need these information to find the source and the cause of the groundwater arsenic poisoning in Bangladesh and West Bengal.
These data will clearly indicate whether the cause of groundwater arsenic poisoning is associated with the oxidation or reduction mechanism. Groundwater systems are far more complex and slower moving than surface water systems. Water resource systems are dynamic in nature. Surface and groundwater resources are integral parts of the same hydro-geological whole. They respond both in quantity and quality to natural changes and human activities such as diversion of surface water and abstraction of groundwater etc. As a result, the water chemistry changes with time when the water moves through the changing environment.
Meer Husain, P.G. Environmental geologist , Kansas Dept. of Health & Environment and Adjunct Faculty Cowley County Community College, Kansas, U.S.A.
May 23, 2004.
Gold mining is by far the largest single source of world anthropogenic arsenic. If all estimated gold reserves are exploited, then gold mining will release estimated 104 million tonnes of arsenic in the environment. This is more than 20 times as much arsenic as has been released from all anthropogenic sources in the industrial age so far. (S. U. Dani, August 24, 2010}.
Recently McArthur et al. (2001) reports neither pyrite oxidation, nor competitive exchange of fertilizer-phosphate for sorbed arsenic, cause arsenic pollution of ground water in Bangladesh and microbial reduction has released sorbed load of arsenic to ground water. But from where this “sorbed load of arsenic” originated is not scientifically documented. They have referred many excellent references but forgot to refer phosphate-fertiliser that caused extremely high ground water contamination in Utter Pradesh, India which is published by renown John Wiley & Sons, NY (1983), edited by Hutchinson and Meema.
Meer Husain quoting the works of British Geological survey and Drs. Pradeep K. Aggarwal of International Atomic Energy Agency, Vienna; Asish R. Basu, Robert J. Poreda of University of Rochester, New York, USA; K.M.Kulkarni of Bhabha Atomic Energy Center, India; K.Froehlich of IAEA, Vienna; S.A.Trafder, Mohammed Ali, Nasir Ahmed of Bangladesh Atomic Energy Commission, Bangladesh; and Alamgir Hussain, Mizanur Rahman, Syed Reazuddin Ahmed of Bangladesh Water Development Board, Bangladesh. reports (The Independent, June 19, 2002):
Scholars such as McArthur et al., Gunnar Jack et al. and Aggarwal et al. believe that the groundwater arsenic poisoning has been present in Bangladesh for thousands of years. They also believe that the groundwater arsenic poisoning is occurring by a natural process. We could not find any reliable evidence/data in their reports that support their findings. On the other hand, the available geological, hydrological, hydrogeological, geochemical, groundwater use data and historical medical data indicate that the groundwater arsenic poisoning in Bangladesh is a recent (post-1975/post Farakka) man-made disaster, and oxidation is most likely responsible for the mobilization of arsenic into groundwater.
The age of the arsenic poisoning is directly related to the source and the cause of the poisoning. The development of arsenic related diseases is directly related to the use of arsenic poisoned groundwater for drinking and cooking purposes. The lag time for the development of arsenic lesion in West Bengal is about 2-5 years (Dr. Shaha, dermatologist). The people of Bangladesh and West Bengal of India have similar food habits, they are physically alike, and their intake of drinking water is also similar. The lag time for the development of arsenic lesion in other parts of the world varies from 8 to 14 years.
In order to examine the age, source and cause of the groundwater arsenic poisoning in Bangladesh and West Bengal of India, we have developed the following questions. The answer and analysis of these questions do not support the source, cause and age of the groundwater arsenic poisoning in Bangladesh as proposed by BGS, McArthur et.al., Gunnar Jack et.al. and Aggarwal et.al.
Redox gradients in soils
Redox gradients in soils and sediments, which are also important in controlling the type and speciation of arsenic, depend on the organic carbon content, sedimentation, and oxygen diffusion. As oxic environments become reduced, MnO2 (with adsorbed As) will reductively dissolve, releasing the sorbed arsenic that could be readsorbed into Fe-oxides. Furthermore, biologically mediated activities involve transformation of various arsenic species (e.g., reduction of As(V) to As(III) and/or inorganic arsenic to organoarsenic). Thus, sediment-bound arsenic may be released back into the overlaying water directly by chemical or biological transformations of other compounds that bind arsenic. Values of partitioning coefficients for arsenic that are employed in contaminant transport modeling range over several orders of magnitude due to the complexity of arsenic biogeochemistry.
MOBILITY OF ARSENIC (not source)
Widespread high concentrations generally result from natural processes, although human activities can increase arsenic concentrations:
The most prevalent causes of widespread high concentrations are release from iron oxide and sulfide mineral oxidation. Upflow of geothermal water and evaporative concentration also can produce high arsenic concentrations in ground water. More than one of these processes can be operative at a given locale. Arsenic can be released to ground water by desorption from, and dissolution of, iron oxide. Aquifers with oxic ground water commonly contain iron oxide with arsenic as an impurity. Desorption of arsenic can be promoted by either an increase in pH or the concentration of a competing ion, such as phosphorous. Arsenic also can be released from iron oxide because of chemical reduction of the oxide. Deposition of Fe-coated sediment along with organic matter can lead to the dissolution of the oxide coating with consequent release of arsenic to ground water. Introduction of synthetic organic compounds into aquifers also can lead to reductive dissolution of iron oxide and arsenic release. Pyrite commonly contains arsenic in trace amounts, although arsenic concentration can exceed five percent. The rate of sulfide-mineral oxidation is limited by the supply of an oxidizing agent, most commonly molecular oxygen. High nitrate concentrations from agricultural activities also can oxidize sulfide minerals. Human activities that increase the supply of oxygen, or another oxidizing agent such as nitrate, to ground water can lead to increased mineral oxidation and, consequently, high arsenic concentrations. Irrigation in arid and semi-arid regions can increase evaporative concentration, which can lead to high arsenic concentrations.
Microbial Arsenic Reduction: A New, Ubiquitous, Yet Still Mysterious Factor in Aquatic Arsenic Mobility :
Microbial arsenic reduction is emerging as a potentially important factor in aquatic arsenic mobility. Investigations of numerous arsenic-contaminated aquatic systems have revealed microbial transformation of As(V), a form that adsorbs strongly to sediment solids, to As(III), a form that is often much more mobile. However, nitrate, phosphate, and oxygen concentrations may limit arsenic-transforming microbial activity. For many contaminants, such as arsenic, sediment/water exchange reactions play an important role in its aqueous environmental chemistry. The problems of arsenic in water supplies and its removal remain as some of the top current issues in environmental health. Furthermore, elevated arsenic concentrations in different environments associated with arsenic wastes have demonstrated the importannce of microbially mediated arsenic transformations. Concern over the impacts of arsenic in water bodies emphasizes the need for information on the factors controlling the types, amounts, and speciation of arsenic exported. An important goal of environmental geochemistry is to understand how reactions of various minerals affiliated with arsenic compounds as well as biological activity influence the migration of arsenic metalloids, but comprehensive information on physical, chemical and biological interactions between arsenic and the surrounding environment is rather limited.
Metal-reducing bacteria cause changes in the mineral structure of the sediments, leading to release of arsenic into groundwater
The study by Farhana Islam, supervised by other researchers, showed the special group of bacteria 'gains energy by respiring (breathing), using the metal iron and arsenic containing minerals in the earth sediments'. The young scientist said, "Our results show that these are the special anaerobic bacteria, as they don't need any oxygen to support their growth. They are known as metal-reducing bacteria. We are very interested in iron-reducing bacteria that use iron as their growth substrate, and can also use arsenic when the iron is used up." The bacteria cause changes in the mineral structure of the sediments, leading to release of arsenic into groundwater, the study says.
Farhana, who studies in the Department of Earth Sciences and Williamson Research Centre for Molecular Environmental Science at the University of Manchester, told The Daily Star, "We are looking at how these processes of breaking down the mineral can be reversed so that the groundwater is safe to drink." She elaborated, "With our results, we found that maximum amount of arsenic was released from contaminated sediment into groundwater in the absence of oxygen."
There were several hypotheses concerning the release of arsenic into the groundwater systems of West Bengal in India, where the researchers worked. Some suggested a role for aerobic bacteria (arsenopyrite oxidation), some suggested a role for metal-reducing bacteria while others considered the problem to be driven by geochemistry. The scientists from Manchester University conducted experiments in their laboratory with sediments collected directly from an area of West Bengal affected by arsenic.
"We were the first group to combine geochemical, mineralogical and microbiological/molecular biology techniques to study this system, and have presented the first direct evidence to support a role for metal-reducing bacteria in arsenic release from the sediments. The organisms identified as playing a key role are iron reducing bacteria that can attack arsenic once they have exhausted iron as a growth element," Farhana explained. Studies showed that this type of bacteria is unable to use oxygen for growth, rather they use different metals to support their metabolism. Metal-reducing bacteria 'breathe' metals such as iron to get energy from their food, in the same way humans breathe oxygen to break down food.
The iron-reducing bacteria use iron through the electron transport system in the anaerobic respiration and gain energy for their growth by reducing this iron. This process is known as dissimilatory iron-reduction.
Explaining the process of arsenic contamination, Farhana said instead of using oxygen, the anaerobic bacteria gain their energy by respiring, (breathing) using iron-containing minerals in the sediments, a process called iron reduction. By doing this, the bacteria transfer electrons to iron oxide rust coating the sediments, causing changes in the characteristics of the minerals. And when the iron runs out, the bugs start to utilise other metals, such as arsenic, which occurs naturally. The chemistry of the arsenic is changed and the reduced arsenic is able to dissolve into groundwater, she said (Daily Star August 14, 2004).
Uses of arsenic, especially in pesticides and wood preservatives, have produced significant environmental contamination
For many contaminants, such as arsenic, sediment/water exchange reactions play an important role in its aqueous environmental chemistry. Elevated arsenic concentrations in different environments associated with arsenic wastes have demonstrated the importannce of microbially mediated arsenic transformations. Concern over the impacts of arsenic in water bodies emphasizes the need for information on the factors controlling the types, amounts, and speciation of arsenic exported. An important goal of environmental geochemistry is to understand how reactions of various minerals affiliated with arsenic compounds as well as biological activity influence the migration of arsenic metalloids.
Microbial transformation of different arsenic contaminants species is often responsible for the distribution and concentration of various arsenic species present in lake, ocean, stream and soil environments. For example, mining activities and microbially facilitated disturbances greatly increase the amount of arsenic releases into both surface and ground waters, producing levels significantly over background. When coupled with deposition of iron oxyhydroxides due to acid min drainage impacts, the biogeochemistry of this trace element becomes enormously complex. Both the iron mineral and other surfaces will concentrate arsenic and act as a storage reservoir.
Redox gradients in soils and sediments, which are also important in controlling the type and speciation of arsenic, depend on the organic carbon content, sedimentation, and oxygen diffusion. As oxic environments become reduced, MnO2 (with adsorbed As) will reductively dissolve, releasing the sorbed arsenic that could be readsorbed into Fe-oxides. Furthermore, biologically mediated activities involve transformation of various arsenic species (e.g., reduction of As(V) to As(III) and/or inorganic arsenic to organoarsenic). Thus, sediment-bound arsenic may be released back into the overlaying water directly by chemical or biological transformations of other compounds that bind arsenic. Values of partitioning coefficients for arsenic that are employed in contaminant transport modeling range over several orders of magnitude due to the complexity of arsenic biogeochemistry.
Rates of Arsenic Oxidation-Reduction Reactions in Contaminated Soils: Effects on Arsenic Fate and Mobility (EPA, USA Research Project)
While adsorption of arsenic onto single oxides has extensively been studied, it is reasonable to assume that intermixing or coating of various chemical species onto minerals would greatly alter this sorption/desorption and redox behaviour. As adsorption onto mixed oxides in the presence of naturally occurring inorganic and organic ions, and on speciation and solubility changes as a result of microbial activity.
Arsenic (As) is an important priority pollutant found in soils contaminated by arsenical pesticides, natural geothermal sources and mine tailings. The chemical and biological processes which control the fate and mobility of As in contaminated soils and mine tailings are complex, primarily due to transformations of numerous As species which occur under temporally variable oxidation-reduction conditions. The objectives of this project are to
- determine rates and underlying mechanisms of the reduction of sorbed arsenate in model systems, contaminated soils and mine tailings;
- evaluate the importance of As-sulfide formation under conditions typical of As contaminated soils and mine tailings; and
- evaluate the role of reduction of sorbed arsenate on the mobility and transport of As in contaminated soils, mine tailings and aquifers
It is hoped that results obtained from this study will improve the link between fundamental kinetic processes controlling As speciation and watershed scale processes such as mobility, transport and bioavailability.
Mobility of arsenic is still imperfectly understood. For example Arsenic-rich pyrite in the Mississippian Marshall Sandstone is still imperfectly understood.. While the amount of pyrite in the Marshall Sandstone and its arsenic concentrations are sufficient to explain the anomalous arsenic in groundwater, the mechanism by which arsenic is released is less certain, as pyrite grains in well cuttings and the Huron Country core appear to be un-oxidized. Preliminary geochemical modeling confirms that pyrite is stable at depth in unoxidized Marshall ground water. This indicates that oxidation occurs elsewhere, perhaps in overlying glacial aquifers containing till derived from the Marshall. But the British Geological Survey (2000, 2001) without detecting the source (origin) announced the Iron Hydro-Oxide theory.
The questions are:
If the Oxyhydroxide Reduction hypothesis is correct and if arsenic was present in an adsorbed form on iron hydroxide for thousands of years and existed in a solution for thousands of years in the aquifer groundwater of the Bengal Basin without being flushed out to sea, how did the people of Bangladesh and West Bengal of India avoid the arsenic poisoning when thousands of people drank water from dugwells for thousands of years and from thousands of tubewells for 60 to 70 years, prior to the 1970s? Also please explain how millions of people in Bangladesh who had been drinking water from millions of tubewells during the interval between the 1960's and prior to 1975, before the construction of dams/barrages and diversion of surface water by India from the Ganges, Tista, and 28 other common rivers of Bangladesh and India, lack signs of arsenic poisoning?"
On January 24, 2001, Dr. Peter Ravenscroft, Chief Hydrogeologist of MML and consultant of BGS in his post in Arsenic-Source Group stated that "My earlier conclusions on the age of contamination were based on general geological reasoning. This interpretation has apparently been independently confirmed by isotopic dating reported by Dr. Pradeep Aggarwal of IAEA, Vienna and his co-workers. They conclude that the contaminated waters have been in the ground for between a few tens and a few thousands of years
Those who suggest an exclusively recent (post-1975) origin would be well advised to examine the IAEA results, and take the argument forwards."
Dr. Bridge, and myself analyzed the various reports and their findings. The available data suggest that the source and cause of the arsenic poisoning is directly related to the abstruction of groundwater and diversion of river water. Dr. Del Fanning, Dr. Chakraborti and Dr.Quamruzzaman's teams also came up with similar conclusions.
Dr Aggarwal and his team in their summary "Isotope Hydrology of Groundwater in Bangladesh: Implications for Characterization and Mitigation of Arsenic in Groundwater" stated that "The exponential increase in groundwater exploitation between 1979 and 1999 does not appear to have affected the overall hydrodynamics of shallow and deep aquifers and, by implication, the arsenic mobilization process. Currently favored mechanisms of arsenic mobilization are found to be inconsistent with isotope data. The most likely process of arsenic mobilization may involve desorption from the sediments as a result of the relatively rapid and continuing (natural) renewal of shallow aquifers with arsenic free water."
If the desorption theory is the mechanism for arsenic release, where are the samples with adsorbed arsenic? What is the lag time for the adsorption of arsenic by iron hydroxide, and what is the age of the ironhydroxide? Dr. Aggarwal and his team did not study the pre-Farakka (prior to 1975) surface water and groundwater data of the Bengal Basin. Their study is based on very limited post Farakka hydrological and groundwater data. As a result, Dr.Aggarwal and his team do not have a clear picture about the surface and groundwater conditions, as well as about the source and the cause of the groundwater arsenic poisoning in Bangladesh.
Dr. Aggarwal and his team did not find any impact on the groundwater level in Bangladesh due to river water diversion from Ganges, Tista and 28 other common rivers of Bangladesh and India. Dr. Aggarwal and his team should know that prior to 1975 in Bangladesh, the area which was underwater for thousands of years is now dry land due to 26 years of river water diversion from the above mentioned rivers
I suggest Dr. Aggarwal and his team to collect pre and Post Farakka river water discharge data of the common rivers of Bangladesh and India, and adequate groundwater level data in Bangladesh to find the impact of India's 26 years of unilateral diversion of river water on the groundwater as well as the source and the cause of the groundwater arsenic poisoning in Bangladesh
Like Dr. Aggarwal et al., BGS investigators could not find any impact of river water diversion and over pumping of groundwater on the cause of the arsenic poisoning in Bangladesh, because BGS did not collect adequate pre and post Farakka river water discharge data and groundwater level data. We would like to know from BGS investigators, why they collected pre-Farakka(prior to 1975) river water discharge data of three major rivers of Bangladesh(Ganges, Bhramhaputra and Meghna) and why they did not collect post-Farakka discharge data of these rivers.
We are requesting BGS, McArthur et.al, Gunnar Jack et.al., and Aggarwal et.al. to take a look at the attached hydrograph of the Ganges river (Hardinge bridge point) in Bangladesh (Source:G.Hebblethwaite's research entitled "The Impacts and Implications of the Farakka Barrage upon Bangladesh" B.S. thesis, University of New Castle upon Tyne, U.K.,1997), to understand the importance of adequate pre and post Farakka river water discharge data of the common rivers of Bangladesh and India, and groundwater level data in Bangladesh for the study of the source and the cause of the arsenic disaster in Bangladesh.
We do not disagree with Dr. Aggarwal's isotopic findings regarding the age of the groundwater, but we do not agree with the age of groundwater arsenic poisoning. The age of the water and the time arsenic entered the water are TWO DIFFERENT THINGS. If arsenic was tied up in minerals that were stable below the water table when the sediments were first deposited and released when oxidation occurred as the groundwater table was lowered at a later date, then the date of arsenic contamination relates to the groundwater lowering not the age of the water
The fact that some of the wells were below the WHO limits for arsenic when they were first tested and later tests detected an increase in concentration of arsenic above safe limits is an indication that recent local changes in the environment caused the change. Oxidation of arsenic pyrite and other arsenic bearing minerals is one possibility for the change. If the water diversion from rivers and the over pumping of groundwater are continued, this process will contaminate both new and old uncontaminated water whether the water is 25 years of old, or thousands/millions of years of old.
For thousands of years Prior to 1975 and before the construction of dams/barrages by India and India's unilateral diversion of surface water from the Ganges, Tista, and 28 other common rivers of Bangladesh and India, the people of Bangladesh drank groundwater from dug wells. If arsenic were present in the ground water it may have been diluted by surface water and the addition of dissolved oxygen may have caused precipitation of some of the arsenic and dissolved iron. During a period of about 60-70 years prior to 1975 some several millions tubewells were installed in Bangladesh. In 1940, about 50,000 tube wells were in use in Bangladesh(former East Pakistan). Millions of people (infants, young and old) drank water from these wells. No occurrences of arsenic diseases were recorded for those people who drank water from these tube wells.
Arsenic-poisoned patients were first discovered in Bangladesh in the early 1990's and in West Bengal in the early 1980's. The historical medical evidence supports a recent origin for the mobilization of arsenic into the groundwater of Bangladesh and West Bengal of India. In our articles we have explained how arsenic pyrite oxidation is one mechanism that could be adding arsenic to the groundwater as a result of change in water table levels.
It appears that Dr.Ravenscroft, Dr. Aggarwal and others have been confused by Aggarwal et al. isotopic findings, and as a result have misinterpreted the "age of groundwater" as the "age of groundwater arsenic poisoning." The historical groundwater use data and the historical medical data are more reliable and dependable methods to determine the age of the groundwater arsenic poisoning rather than isotopic and other methods. The geological, hydrological, hydrogeological, geochemical, historical groundwater use data and historical medical data do not support the age, source and the oxyhydroxide reduction and the desorption theories for the mobilization of arsenic into the groundwater of Bangladesh as proposed by BGS, McArthur et al., Gunnar Jack et al. and Aggarwal et al.
We are respectfully requesting Dr. Aggarwal and his team to answer the following question: Why should the "age of the groundwater arsenic poisoning" in Bangladesh, determined by Aggarwal et al. not be considered incorrect?
Arsenic contamination is directly related to the abstruction of groundwater and diversion of river water can not be supported for southern Bangladesh. This means, in other words, lowering of ground water level. In Southern Bangladesh for example Noakhali, one of the worst affected areas, show ground water level is almost the same, where a high amount of water abstracted is replaced by saline intrusion..
With funding comes control over the specific content of research projects. The industry or likely organization uses lucrative research contracts and grants to establish close links with training colleges, universities and research institute. Not surprisingly, there is a very human tendency for researchers to go along with what their funders require of them, even at the cost of compromising public health or the environment (Clunies-Ross and Hildyard, 1992)
This has been overlooked or ignored on what ever the reason may be that arsenic concentration could not be correlated with iron content – water containing high amount of dissolved arsenic does not mean contains high concentration of arsenic. There is high concentration of arsenic but contains very low amount of dissolved iron; in other words, iron-oxyhydroxide theory is not applicable in case of Bangladesh. BGS and MML (UK) (1998) believe that older aquifers are not contaminated due to two factors, firstly due to less reducing and secondly because of stable iron oxyhydroxide that adsorbed arsenic. In that case, a high amount of adsorbed arsenic must be present in the sediments or as dissolved formed in fossil waters but it shows normal background level.
In case of sorption and desorption under oxidation- reduction condition – iron acted as a carrier not as a source. Iron in all geological formation in Bangladesh was formed predominantly under postdepositional weathering of silicate minerals, not from the deposition of colloidal particles. BGS and MML (UK), 1998 presented a corroded grains of oxyhydroxide but does not contain detectable levels of arsenic. Besides, very low concentration of sulphate that presumably washed away in the sea (British Geological Survey and MML UK, 1998) is not imaginable, when at sea level low 18,000 years ago the Ganges river was flowing several hundreds of kilometres away from present coast of Bangladesh and post glacial period was marked by arid climate and relatively low precipitation.
Arsenic in Groundwater: Geochemistry and Occurrence, edited by Alan H. welch and Kenneth G. Stollenwerk (2003), reviewed by Dr. Charles Harvey of MIT, groundwater-book review, vol. 47 No.2-groundwater-March-April 2004"Their work was not based on correct scientific data and evidence. The review of their work also revealed that DPHE/BGS investigators were biased in establishing the reduction theory for the mobilization of arsenic into the groundwater of Bangladesh".
Hypothesis regarding the source and cause of the arsenic disaster in West Bengal of India and BangladeshMeer Husain, P.G., Professional Geologist, Kansas Dept. of Health & Environment September 2006 reports:
Dr. Sabyasachi Sarkar of IIT (India) may or may not have presented an acceptable hypothesis regarding the source and cause of the arsenic disaster in West Bengal of India and Bangladesh in the newspaper “DESH“, Kolkata, India. But as of yet, has any one presented or published an acceptable hypothesis/theory in any scientific journal. Why is it taking so long to establish a correct theory based on sound scientific data and evidence. Can anybody answer these questions based on sound geological, hydrological, hydro-geological, geochemical data, arsenic toxicity data, historical groundwater use data from dug-wells and tube wells, and historical medical data?
I think the people of Bangladesh and West Bengal of India have a right to know from the scientists what is really causing this problem? I strongly feel that the newspaper ”DESH” and all other Bangla newspapers should publish scientific articles, because science is for everybody and science is not the property of any particular group of scientists. The author of an article must be careful about his/her data so that the readers are not mislead by the article, because the groundwater arsenic poisoning in Bangladesh and West Bengal of India is a serious health and environmental issue, and this is the largest disaster in the history of human civilization.
Those Scientists who have been suggesting for about a decade that the groundwater arsenic poisoning in West Bengal and Bangladesh is a NATURAL disaster, that the poisoning has been present into groundwater aquifers of Bengal Basin for thousands of years and that Reduction is the principal mechanism for the mobilization of arsenic into groundwater, lack sound data and evidence in support of their hypothesis.
The proponents of natural disaster have generated a lot of data, however their works are based on incorrect and inadequate data and they were biased in their hypothesis. The have rejected the OXIDATION mechanism without examination and investigating the hypothesis, whereas their own data and that of others strongly indicate that the arsenic disaster in Bengal Basin is a recent man-made disaster.
I do not understand how knowledgeable scientists, journalists, policy makers, politicians of West Bengal of India and Bangladesh can accept and promote such an erroneous theory (in the context of Bengal Basin): that the groundwater arsenic poisoning in Bengal Basin is a natural disaster when millions of people are being poisoned by deadly arsenic on a daily basis for about a decade.
I strongly believe that the people of Bangladesh and West Bengal of India and the scientific community around the world are confused about the source and cause of the arsenic disaster in Bengal Basin. If we do not know the source and cause of the problem, then how can we develop a correct solution to the problem? We should systematically discuss these issues and eliminate the wrong and biased data / hypothesis and establish the correct theory regarding the source and cause of the problem.
We can form an internet based scientific discussion group and invite scientists, journalists and policy makers around the world to participate in the discussion. If you are interested to form such a group, please let me know.
I will continue to share scientific data and evidence that reject the hypothesis that the groundwater arsenic poisoning in Bangladesh and West Bengal of India is a NATURAL disaster and that the poisoning has been present into groundwater aquifers of Bengal Basin for thousands of years.
Hazards of pesticideThat the quality of the country's surface water has markedly deteriorated is a matter of great concern. But the nature and extent of the fall in quality was not precisely known. Now the Bangladesh Atomic Energy Commission (BAEC) has determined through laboratory tests that surface water of different regions is contaminated enough to cause our anxiety. The culprit is none other than toxic chemical pesticides.
In some areas the level of chemical particles, including DDT, present in the water is quite alarming. The water collected from Begumganj has a DDT contamination much higher than the permissible level adjudged by WHO.
The presence of other types of chemical particles too has been found to be very high. Even the BAEC's survey is not comprehensive because it has not tested water samples from all across the country. But at least it is indicative enough. So what is the message?
Residues of extremely toxic pesticides in surface water show that such pest-controlling agents are either used indiscriminately, or they are simply the banned types. We suspect some brands of chemical fertiliser can also contribute to the contamination of water. So there is a need for bringing an end to the marketing of such harmful toxic pesticides and fertiliser in the first place.
Contaminated surface water is known to have adversely affected all kinds of water species, the fish in particular.What is, again, lacking is a scientifically established proof of the damage caused to the water bodies, the living beings there, and the environment. No such attempt has ever been made to determine how long we can continue using the chemical fertiliser and pesticide without inviting an environmental disaster for us.
A comprehensive test of the country's water sources can be a first step in that direction. Surely, we need to control pests, but this has to be environment-friendly. Already arsenic contamination of underground water has posed a serious health problem in some areas of the country and if we pollute the surface water beyond any remedy, we shall be permanently endangering the future of millions. Only a few natural pest management options are known but when the danger from chemical agents is so great, those limited options have to be extended through research and experiments.
Source: The Independent, 21 December 1997.
CHEMICAL IDENTITY -- SODIUM CACODYLATESynonyms: Arsine Oxide, Dimethylhydroxy-, Sodium Salt; Alkarsodyl; Ansar 160; Ansar 560; Arsecodile; Arsicodile; Arsine Oxide, Hydroxydimethyl-, Sodium Salt; Arsinic Acid, Dimethyl-, Sodium Salt; Arsycodile; Arsysodila; Cacodylic Acid Sodium Salt; Cacodylic Acid, Sodium Salt; Chemaid; Hydroxydimethylarsine Oxide, Sodium Salt; Rad-E-Cate; Silvisar; Sodium Dimethylarsinate; Sodium Dimethylarsonate; Sodium Salt of Cacodylic Acid; [(Dimethylarsino)oxy]Sodium
HEALTH HAZARD DATA
OSHA PEL: (Arsenic and compounds) TWA 0.010 mg/m3, as arsenic (NIOSH 1987, p. 54) ACGIH TLV: (Arsenic and soluble compounds) TWA 0.2 mg/m3 (ACGIH 1986-87, p. 10). Other Limits Recommended: (Arsenic and compounds) NIOSH: 0.002 mg/m3 15- minute ceiling, as arsenic (NIOSH 1987, p. 54)
Routes of Entry: Ingestion: Yes (Hayes 1982, p. 42)
Health Hazards (Acute, Delayed, and Chronic): Moderately toxic; probable oral lethal dose in humans is 0.5-5 g/kg or between 1 ounce and 1 pint (or 1 lb.) for a 70 kg (150 lb.) person (*Gosselin 1976). It may cause disturbances of the blood, kidneys, and nervous system (*Sax 1975).
US EPA, 1987.
Ratan et al. (1997) reports possible hazards associated with metals of surface water bodies of Bangladesh due to anthropogenic activities. Surface water samples from Rajrampur of north-western Chapai Nawabganj (one of the worst arsenic affected areas). The surface water investigated by Peuraniemi, V., Institute of Geosciences and Astronomy. Oulu, Finland (1999) which reports that the largest lake at Rajrampur is surrounded by agricultural land contain by far the highest level of arsenic, likely derived from agriculture. They also reported elevated concentrations of As, Cr, Cu, Ni, Pb and Zinc in soil samples (Islam, et al., 2000).
The average composition of nonfiltered water samples:
Heavy Metals Standard*µg/l Rajarampur µg/l Shamta µg/l As (Arsenic) 4 97,05 15,36 Cr (Chromium) 0,7 1,41 5,65 Cu (Copper) 3 7,71 18,3 Ni (Nickel) 0,3 4 6 Zn (Zinc) 3 8,03 16,56 Pb (Lead) 3 8,03 16,56
*Standard – typical values taken from Wedepohl (1969-79) for surface water
Chromium in surface water exceeds the worldwide average value; the pH value of soil is around 8, at which chromium is not supposed to be mobile and available in surface water. Chromium occurs with ultrabasic rocks at the very early stage of magma crystallisation. Catchment areas of Ganges delta do not show any source. Nickel in these surface water exceeds the average world-wide value several fold (Islam et al, 2000).
Safiullah (1998) also reports concentration of arsenic (0.035 mg/l) in surface water of Kumar River at Faridpur. On December 21, 1997 the daily The Independent reports that the quality of country’s surface water has markedly deteriorated is a matter of great concern, but the nature and extent of the fall in quality was not precisely known.
Human activities can alter natural relationship of surface and ground water:
- After the construction of Farakha barrage and during dry period (Dec-April) ground water table in Bangladesh drop to such extent that surface water bodies disappear as they drain into the falling ground water table.
- During monsoon water table is very high, bringing the ground water table close to land surface resulting the near-surface and surface water can pick up agrochemical as contaminants.
- Irrigation has potential to hasten leaching of applied and natural chemicals.
- Over-pumping water wells can caused “cone depression”. If the cone depression is large, it can change the slope of the ground water table – contaminated water can flow downslope along the cone of depression.
Deterministic and statistical models of transport in soils, atmosphere, surface and ground waters developed by Center researchers continue to improve. These models range 'in scale from origin and movement of groundwater and assessment of long-term degradation of these waters to regional scale atmospheric models used to calculate transport of air pollutants from source areas within large geographic areas. These models have also been coupled with hydrologic models of runoff to quantify patterns of erosion and input of nutrients and other chemicals to lakes and rivers. Center for Ecological Health Research, niversity of California reports (1996):
A new method for probabilistically quantifying the origins and ages of groundwaters arriving at discharge points (e.g., wetlands, wells) was developed that also rigorously accounts for the physical process involved in pollutant transfer between different geologic materials. Results indicate that the currently observed deterioration in groundwater quality in a typical alluvial groundwater basin is due to land use practices in the 1940's and 1950's and that the deterioration may continue for many decades, thereby eventually impacting any wetlands and streams that are sustained by groundwater discharge.Top of page
Matthew L. Polizzotto*, Charles F. Harvey†, Steve R. Sutton‡, and Scott Fendorf*§ *Department of Geological and Environmental Sciences, Stanford University, Stanford, CA 94305; †Parsons Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139; and ‡Consortium for Advanced Radiation Sources and Department of Geophysical Sciences, University of Chicago, Chicago, IL 60637 (June 11, 2005) suggest that suggest that arsenic may be released in the near surface and then transported to depth. We establish that
(i) the only portion of the sediment profile with conditions destabilizing to arsenic in our analysis is in the surface or near-surface environment;
(ii) a consistent input of arsenic via sediment deposition exists;
(iii) retardation of arsenic transport is limited in the aquifers; and ( iv) groundwater recharge occurs at a rate sufficient to necessitate continued input of arsenic to maintain observed concentrations.
Our analyses thus lead to the premise that arsenic is liberated in surface and near-surface sediments through cyclic redox conditions and is subsequently transported to well depth. Influx of sediment and redox cycling provide a long-term source of arsenic that when liberated in the near surface is only weakly partitioned onto sediments deeper in the profile and is transported through aquifers by groundwater recharge.
Sediment samples were obtained from the Munshiganj district of Bangladesh, 30 km south of Dhaka and 7 km north of the Ganges River. Our field site is located centrally in Bangladesh with geological and hydrological conditions typical of the areas worst affected by arsenic; geochemical conditions are similar to those sites with high dissolved arsenic as discussed in the Bangladesh-wide British Geological Survey study (ref. 10 and www.bgs.ac.uk_arsenic_Bangladesh).
The site encompasses 16 km2 and is thus considerably larger than the dominant scales of spatial heterogeneity (tens to hundreds of meters) in dissolved arsenic in the worst-affected areas, yielding findings of widespread utility.
The subsurface at our location consists of a surficial clay, a Holocene aquifer of gray sand, a clay aquitard, and a deep, burnt-orange sandy Pleistocene aquifer.
Core extraction procedures and groundwater aqueous chemistry were summarized previously (9). Arsenic concentrations in the groundwater increase with depth to a maximum at _30 m and then decrease with increasing depth; solid-phase arsenic concentrations in the Holocene aquifer are below 3 mg_kg (4).
Results and Discussion
The current paradigm within Bangladesh and West Bengal is that Fe(III) (hydr)oxides remain the dominant host of arsenic even at well depth (i.e., 30 to 50 m) within contaminated aquifers, and that organic carbon derived either from the surface (4) or from detrital material (2, 3, 6) is stimulating reductive dissolution of the iron phases and concomitant release of arsenic.
Here we explore operative redox processes impacting arsenic partitioning between the solid and aqueous phase by using multiple lines of data, inclusive of detailed spectroscopic measurements, batch experiments, and field observations.
. Laboratory batch experiments and previous in situ injection- withdrawal tests (4) both reveal rapid desorption of arsenic from the sediments, indicating that arsenic is more labile than would be expected if it were bound to ferric (hydr)oxides.
Arsenic is released from gray Holocene sediment solids by the simple addition of water, and thus amendment with labile organic carbon [e.g., lactate (Fig. 3) or acetate (14)] is not necessary to invoke rapid desorption of arsenic. In contrast, arsenic remains in the solid phase with the addition of ferric (hydr)oxide to sediment incubations (.
Groundwater Flow and Arsenic Transport.
Groundwater tritium concentrations at our site (15), and across Bangladesh (16), indicate a residence time of typically _50 years in the upper 30 m, consistent with the rate of irrigation withdrawal (15, 17).
Three scenarios therefore may explain the current aqueous arsenic concentrations:
i) groundwater flow was much slower in the past such that arsenic was not flushed from the Holocene aquifer, (ii) geochemical conditions have recently shifted to mobilize arsenic, or (iii) dissolved arsenic is provided by a source that is hydrologically upgradient of the sampling wells.
. Surface sediments, which typically have higher solidphase arsenic concentrations than the aquifer materials (9, 18, 19), can provide a source of arsenic, potentially maintaining constant aqueous arsenic concentrations downgradient in areas where groundwater velocities and_or solid-phase arsenic concentrations are modest
. Assuming a downward component of groundwater velocity of 1 m_yr (17), arsenic concentration of 1 _M [the approximate national average (ref. 10 and www.bgs.ac.uk_arsenic_Bangladesh)], sedimentation rate of 1 cm_yr, and 50 nmol of arsenic mobilized per gram of surface sediment [_1_4 of typical surface sediment concentrations (9,19)], the groundwater arsenic flux and input by sedimentation are comparable, both equal to 1 mmol As m_2_y_1.
This calculation suggests that steady groundwater concentrations could be sustained by sediment deposition in areas where groundwater velocities and dissolved arsenic concentrations are modest. However, where arsenic concentrations are higher, such as our site in Munshiganj (8 _M) (4), or when sedimentation rates are lower, the observed arsenic concentrations suggest hydrologic or geochemical transience.
Our hydrologic data (17) reveal residence times on the order of 80 yr without irrigated agriculture; with irrigation pumping, residence times decrease to _40 yr-the recent onset of irrigation pumping increases recharge rates by a factor of 2.
The recent alteration in irrigation pumping has changed groundwater flow patterns, decreasing the residence time of groundwater and perhaps flushing arsenic (6, 15) from the Holocene aquifer. Dry season rice cultivation, now covering _25% of the country (20), is irrigated with _1 m_yr of groundwater (17), which, assuming a porosity of 25%, causes an average downward component of groundwater velocity of _1 m_yr to the depth of well screens.
Arsenic Release Through Deposition Combined with Redox Cycling
One potential upstream source of arsenic is the near-surface sediments, where, as noted above, sedimentation fluxes can sustain groundwater arsenic concentrations.
Three pathways may lead to arsenic release within the surface and near-surface soils_sediments, all involving Fe and As reduction.
First, recently deposited sediments containing As(V) associated with ferric (hydr)oxides will undergo reduction upon the following seasonal addition of organic carbon (surface-derived) and flood waters. Solid-phase arsenic is deposited in association with detrital sulfides and ferric (hydr)oxides. Ferric (hydr)oxides dissolve, as illustrated by increasing Fe(II)_Fetotal ratios with depth (8), in concert with As(V) reduction to As(III) as the sediments are buried to the depths of the gray aquifer material. Second, seasonal cycling in aerobic_anaerobic conditions will lead to the destabilization of arsenic-bearing sulfides, which contain _10 g_kg of arsenic and are thus major repositories of this toxin. Seasonal water-table oscillations (refs. 4, 10, and 17 and www.bgs.ac.uk_arsenic_Bangladesh) establish an oxic-anoxic cycle in the surface and near-surface sediments.
During the dry season, sulfide minerals will be oxidized, leading to the repartitioning of arsenic into ferric (hydr)oxides (21), followed then by reductive dissolution of iron and arsenic during the ensuing wet season.
Cyclic redox conditions in the near-surface sediments would therefore accelerate sulfide weathering and release of arsenic, consistent with processes noted for mining impacted environments (22). The presence of both detrital and authigenic sulfides demonstrates, in fact, that redox cycling is occurring, and fluctuating redox conditions have been proposed based on _34S measurements (23).
Finally, a third means of arsenic liberation to the aqueous phase may result from changes in conditions that enhance the reducing intensity of the redox cycle, such as increased periods of field saturation.
An area within the soil_sediment profile (down to depths of 80 m) consistently having arsenic concentrations _10 mg_kg exists within the upper 2 m of the surface, precisely where the greatest biogeochemical activity resides. Arsenic exists at concentrations in excess of 1,000 mg_kg (18) within iron bands created by past redox conditions (24).
Moreover,microbial reductive mobilization of arsenic from sediments of the oxic-anoxic boundary has been observed (25), demonstrating the potential for arsenic release under the onset of reducing conditions at the near surface. Once partitioning into the aqueous phase, dissolved arsenic may then enter the aquifer during recharge.
Summary and Conclusions
Transport of carbon into the aquifer undoubtedly creates reducing conditions, and the high levels of dissolved molecular hydrogen and methane indicate that ferric iron no longer serves as a primary electron acceptor.
High concentrations of young inorganic carbon correlate strongly with arsenic, ammonium, methane, and calcium and inversely with sulfate concentrations in the Holocene aquifer in Munshiganj (4), implying that the most significant biological processes occur upgradient and mix during transport.
Furthermore, the bell-shaped vertical profile of these solutes (4) is typical of plume migration from a surface source. After solute enters an aquifer, plume movement is dominated by lateral transport away from the surface source, but recharge also displaces the plume downwards, so local sources create bell-shaped vertical solute profiles.
Groundwater flow has a large lateral component because the distance between discharge areas (irrigation wells and river channels) is greater than the aquifer thickness.
We therefore suggest that both inorganic carbon and arsenic are signatures of biological processes upgradient, likely reflecting surface and near-surface processes (anaerobic -aerobic cycles induced by the influx of carbon-rich surface waters after dry-season draw-down), that are transported along groundwater flow paths until reaching wells in the sandy aquifer.
Organic carbon from the surface would be consumed rapidly, and arsenic, as arsenite, could easily be transported because of its low distribution coefficient in the sediments. Seasonal cycling in redox conditions coupled with annual deposition therefore could account for the liberation of arsenic to the aqueous phase.
We therefore hypothesize that surface and near-surface biogeochemical processes mobilize arsenic in Bangladesh and that these processes, coupled with arsenic transport through the aquifer, should be the focus of further research.
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Polizzotto et al. PNAS _ December 27, 2005 _ vol. 102 _ no. 52 _ 18823
"We found very little arsenic contamination at depths greater than 150-200 m or approximately 500-650 ft. Only about 1% of the deep wells we tested were contaminated. Even the earlier surveys, where we suspect the well depths were not always recorded accurately, showed that only 2 - 3% of the deep wells were contaminated. The main reason for the deep wells being safe is probably because the sediments are older and any arsenic present was flushed out thousands of years ago "(BGS, 1998).
The survey of the British Geological Survey and MML (UK) (1998) shows that the deep aquifers that occurs mainly in the southern Bangladesh is arsenic free, where as the surface aquifers are highly contaminated. Systematic sampling under the project “Ground Water Studies for Arsenic Contamination in Bangladesh” showed only 2 out of 280 wells deeper than 200 meter to be contaminated (BGS, MML UK, 1998).
Most of the deep wells occur in the coastal area of Bangladesh Overlying the deep aquifer is a thick clay sequence generally between 200 to 500 feet thick, which acts as a confining layer and protects the deep aquifer from the leakage of saline water at shallower depths: Shallow wells in this area show arsenic contamination, where as thick layers of clay sequence inhibits contamination recharge from shallow aquifers.
Morton and Khan (1979) have shown that the deep aquifer becomes unconfined in the northerly direction from the coast and is in hydraulic continuity with shallow aquifer, likely to be contaminated with arsenic in course of time. when charged with contaminated water from upper aquifers. However, movement of arsenic in ground water is slow, of an order a few metres per year (BGS and MML UK, 1998).
Concentration of Arsenic in Shallow and Deep Aquifer Wells
Southern Bangladesh Khulna Division Shallow Aquifers Max. Conc. AS mg/l (St. 0.05mg/l) % of Contaminated wells Deep Wells > 200 m Fakirhat 1.00 40% 0% Chuadanga 0.841 35% 0% Khulna Metro 0.500 13% 0% Batighata 0.280 11% 0% Dghalia 0.430 18% 0% Rupsha 0.650 32% 0% Shalikhira 0.120 40% 0% Bagerhat 0.160 44% 0%
Source: British Geological Survey and MML U.K, 1998
The shallow aquifer, on the other hand, contains up to 200 to 300 feet below surface level complex mixture of fine sand, silts and clays deposited in a delatic arc environment, which could be confined as one unconfined aquifer (Morton and Khan, 1979). Since most of the deep aquifers are arsenic free and shallow aquifers are contaminated, it strongly indicates no natural arsenic rich sediments are deposited in Bengal Basin.
The deep aquifers are posing extreme danger of contamination, if special drilling method on contaminated aquifer is not taken. Besides the abandoned water wells must be sealed properly, so that deep aquifer is not contaminated. Unfortunately, no such effort or regulation has been taken in Bangladesh.An Incorrect Arsenic Map of Bangladesh
Bangladesh soil is extremely poor in phosphate. In natural bodies weathering of rocks probably accounts for most of the level of phosphorous observed. The rock mineral involved is apatite family (Fluor-, calcium-, hydroxy, and oxyapatite) and various calcium phosphates, of which are extremely insoluble in aqueous solutions. The mobility of phosphate in a given sediment type is controlled largely by the oxidation state of Fe, which is oxidation-reduction or redox potential of the sediment system. – possible existence of numerous redox couples as well as kinetics of Fe oxidation/reduction probably serve as a sink for Phosphorous.
Phosphate (P0 4average concentration shows the following results (average concentration) in Bangladesh (Bogora, Rajshahi, Bheramara, Pabna, Laximpur) (Brömssen, 1999):
Depht in meter (PO4µg/l As (total) µg/l As (III) µg/l As (V) µg/l TOC mg/l Mg2 mg/l Fe (total) mg/l 0 - 20 1349 333 247 41 5.1 47 6.9 20 -40 444 234 209 84 3.9 34 3.7 40 18 15 3 3 2.3 16 1.1
Phosphate concentration in porewater (at 3-4 meter depth) from W. Bengal shows 24-59 µµg/l and arsenic (total) 5-6 µµg/l comparatively low due to greater presence of HFO (Hydrous Ferric Oxides) and thereby adsorption of phosphate and Arsenic onto the HFO (Brömssen).Investigations by the BGS and MML (UK) also confirm that phosphate positively correlates with arsenic. High phosphate concentration relates with high arsenic concentration. There are several research works that total sorption of phosphate occur through the formation of metal phosphate coating on metal (hydr)oxides.Phosphate has the advantage that there is no direct interaction between this ion and humic materials and effects of pH on phosphate adsorption are relatively small. In that case during the transport of ironoxyhdroxide phosphate will mainly occupy adsorption surfaces, whereas due to lack of space less arsenic will be transported to Bengal delta.
While adsorption of arsenic onto single oxides has extensively been studied, it is reasonable to assume that intermixing or coating of various chemical species onto minerals would greatly alter this sorption/desorption and redox behaviour. Nevertheless, more research is needed on arsenic adsorption onto mixed oxides in the presence of naturally occurring inorganic and organic ions, and on speciation and solubility changes as a result of microbial activity. and complexity and hetrogeneotity of geological formation. Movement and concentration of arsenic is a function of speciation and soil type – as it is seen in Faridpur where arsenic possibly moved from (Char aleka,rice fields) channel sand deposits to the river bank villages, where clayey to silty sediments accumulated arsenic that in course of time under reducing condition contaminated ground water (Anwar, 1999). By completing a multi-faceted experimentation on the chemical and biological transformations of various arsenic species, will add greatly to the knowledge base on arsenic fate and transport through the determination of equilibrium and rate parameters but laboratory experiments do not still quantify natural environment. And U. S. Environmental Protection Agency (EPA) has set up several research projects in the past, present and future targets.
If phosphate is added during “Fertiliser-Seed-Water” (Green Revolution) that expelled /desorpted arsenic that ultimately found in soluble form raises question whether Phosphate and Arsenic simultaneously applied by new agricultural practice that was introduced about three decades ago. The above table and fig.. show that the top aquifer is most intensively contaminated and has close relation for recharge, percolation with upper soil horizon. Since there is any prove for natural occurrence of both phosphate and arsenic in bed rocks, the application of contaminated fertiliser was mainly responsible for contaminating drinking water in Bangladesh.
In 1987 SCOPE (Scientific committee on problems of the Environment, Paris) published scientific papers on Lead, Mercury, Cadmium and Arsenic in the Environment” of various parts of the world. C.R. K. Murti (1987) Centre for Environmental Studies, Madras, India, reports high arsenic in drinking water and vegetables in Chandigarh, Meerut District of Uttar Pradesh, where non-cirrhotic portal fibrosis was endemic..Datta (1976) and Datta and Kaul (1978) found extremely high arsenic in Superphosphate as shown in the following table:
Arsenic content of manure/fertilisers Used in India (Datta, 1976):
Fertiliser Dry weight mg/100 gm Poultry manure I 13.3 Poutltry manure II 23.7 Cow-dung 11.2 Superphosphate 187.8
Arsenic concentration in ground water has been correlated mainly with the use of Superphosphate (Murti, 1987). Bangladesh and W. Bengal, India started green revolution thirty years ago – agrochemical that was not known before massively increased without control and the knowledge of adverse consequences. If phosphate fertilisers contain such a high arsenic concentration as hazardous waste, application of these fertilisers correlates to present contamination. Acharyya et al. (1999) reports during the past thirty years, ground water has been used increasingly for irrigation and the use of phosphate fertilisers has increased threefold and desorption arsenic occurred due to the application of phosphate fertilisers. But if phosphate fertilisers are contaminated with arsenic as in Utter Pradesh, arsenic contamination will occur anywhere, as it has been seen in Sitakund. Miresshwari, in Chittagong Division where source rock is Arakan-Yoma range
The border region of Bangladesh and India is an open free market, where fertilisers and others imported or exported legally or illegally depending on market situation. Farmers of Bangladesh always suffered from the application of agrochemical – firstly they do not posses any knowledge about agrochemical, secondly traders stock-piles the chemicals to make an artificial scarcity that sky rises the price and thirdly a very low quality of fertilisers or pesticides with unknown added constituents are introduced in the market. There are any controlling authority, when exists, do not posses any capability to analyse heavy metals or chemicals. If one looks at the column of district news in daily newspaper of Bangladesh will find several protests of the farmers in the areas now extremely arsenic contaminated area. On February 27, 1995 the Daily Star reports:
The fertility of soil in Natore and northern region of the country have been decreasing day by day due to extensive use of chemical fertilisers and banned harmful smuggled Indian pesticides reports UNB. Local people said farmers prefer Indian pesticides for its cheaper price of locally produced one is double in the market.... Experts said farmers use those pesticides to increase production without knowing its adverse effect to fertility of soil. The pesticides have already been banned in India long ago.. For the indiscriminate use of these banned pesticides, paddy leaves become discoloured. Besides it kills frogs, fish and other insects which are helpful for crop production.. Local leaders urged the government to take immediate measures to stop indiscriminate measures to stop indiscriminate use of Indian smuggled harmful pesticides and chemical fertilisers.
If one look at the daily newspaper can find news like the whole family died after eating spinach that was collected from the rice field. The daily Bangla Bazaar Patrika on March 7, 1995 reports from Magura, south-west Bangladesh (one of the worst arsenic affected areas of Bangladesh):
There is a severe scarcity of bio-fertilisers. The farmers have no alternative - excess chemical fertilisers and pesticides and mono cropping have dramatically decreased agricultural production Farmers are ignorant of "modern agriculture"...
On March 7, 1995 Bangla Bazaar Patrika reports from Rupsa, Khulna:
In Khulna division unregistered pesticides and excessive use of fertilisers application has dramatically decreased the fertility of soil. These agrochemicals are smuggled from India and sold at cheap price openly in the village market.
On March 9, 1995 the daily Bangla Bazar Patrika writes on excessive and improper use of fertilisers in south of Bangladesh created soil erosion (Kamruzaman Bachu):
Organic content in the soil of South Bangladesh (Patuakhali, Bargana, Bhola) has dramatically decreased and improper use of chemical fertilisers has changed the composition of soil character. Farmers apply fertilisers without knowing the requirement and an excessive amount of fertilisers are applied to soil which has resulted soil erosion (deficient in organic matter and essential munerals).
Most of the farmers do not know what is added to the fertilisers and they usually complained because of the certain colour of the fertiliser or due to the destruction of their plants. Daily Banglabazar Pratika reveals from Magura on December 20, 1995:
Contaminated TSP fertiliser is sold in the market of Shalikhira (Magura). Dark grained TSP fertilisers from the USA has high demand and sold for Tk. 450/bag. Traders mix SSP fertiliser with used oils (hazardous waste) and sell as TSP fertiliser.... It has been reported that soil has almost lost all productivity. The production of crops has dropped to 50 percent than a decade ago.
Omar Faruque interviewed farmers from village Kulia in Stakhira district ,south-west Bangladesh ( Chinta, no. 12, Feb. 15, 1995).:
Azharul Islam, a village farmer reports that in mid 1992 he bought 30 kg fertiliser and applied to his rice plants. At first the plant became green but within in a short time the plant began to foul and within 14 days all crop was lost. His soil never recovered from this lost... Dulal Pad Sarkar also faced the same result. He said that the following year rice yield was also very bad – produced rice was black in colour and it was not possible to eat this rice.
Since the introduction of agrochemical there are several reports of contaminated products. No authority took any care of it. They argue that farmers are using excessive fertilisers. The use of fertiliser to grow high yield varieties (HYV) has brought severe damage to the soil.
There are several areas in the U.S.A. and Canada where the ground water is contaminated with the application of arsenic based pesticides. No body knows the composition of the no name pesticides that are sold in the market. A study on pesticides used in Bangladesh found that some pesticides contain arsenic such Fudanon, 10G produced by Ciba Geigy (personal communication). A number of derivatives of phenyl arsenic acid (PhAsO(OH2) ) have bactericidal, biocidal, or pharmaceutical properties. A study on lower Rhine section of the Netherlands showed that a strong decline in arsenic registered after the ban the use of arsenic containing pesticides (Föster and Wittmann, 1983).
Uranium is a naturally occurring element. Uranium is used primarily as fuel in nuclear energy plants. It may enter drinking water from naturally occurring deposits or as a result of human activity, such as mill tailings and phosphate fertilizers.
In water, uranium has no taste, smell, or colour. It can only be detected through a chemical test. The Canadian drinking water quality guideline for uranium is 0.02 milligrams per litre (mg/L).
Uranium levels in drinking water above 0.02 mg/L can increase the risk of kidney damage. The risk to human health is through ingestion only – drinking, cooking, teeth brushing. Well water with uranium levels greater than 0.02 mg/L may be used for bathing, handwashing, and dishwashing. Phosphate fertilizers may contain uranium at an average concentration of 150 ppm and can also contribute uranium to groundwater.
The NPWA has a long-standing concern about the phosphate fertiliser industry. Fluorosilicic acid (H2SiF6), used to fluoridate drinking water, is derived from the pollution scrubbing operations at those facilities. We have built up a considerable understanding of phosphate rock (PR). The raw rock (which during phosphate fertiliser production is extensively processed) is contaminated with heavy metals, radionuclides, other toxic metals and fluorides. It is recommended for use as an organic fertiliser in its raw state.
The use of phosphate fertilisers is a major contributor to environmental pollution (Phosphate Rock Fertilizer, George Glasser - Ros Jones National Pure Water Association, Campaign for Safe Drinking Water,Founded in England, 1960: George Glasser - Ros Jones: February 22, 2009).
Accumulation of uranium derived from long-term fertilizer applications in a cultivated Andisol, Japan
The U concentrations in the soils of experimental fields with continuous fertilizer applications and in neighboring non-agricultural soils were determined. The surface soils in the three experimental fields with fertilizer applications contained higher amounts of U compared with the non-agricultural surface soils. The amount of U elevated in the soil was estimated by the vertical profile of U concentration, and an increase of about 200 mg m- 2 of U was found in the soils at 0–35 cm depth during a 61-year cultivation period.
The estimated value was almost the same as the amount of U added through the fertilizers as calculated from U concentrations in the applied fertilizers. Therefore, almost all the U from the fertilizers would still remain in the upper part of the soils. Chemical extraction results suggested that organic substances and noncrystalline clay minerals in the surface soil should play an important role for accumulation of U derived from the fertilizers.
(Department of Radioecology, Institute for Environmental Sciences, 1-7 Ienomae, Obuchi, Rokkasho, Aomori, 039-3212, Japan, 2005)
Rock phosphates are so high in un-depleted uranium that several mines are on offer as uranium deposits. Morocco is the largest world exporter and its phosphate is in that list. Europe and Japan have male fertility problems, and both use Moroccan phosphateNever mind depleted uranium, the farms are full of the hot stuff Top of page
There has been a huge fuss about the health and pollution problems that have arisen in Eastern Europe, as the result of the use by NATO of depleted uranium shells in Kosovo (9 tonnes admitted to) and Serbia (3 tonnes admitted). But, coming in under the radar, those of us who live in the rich world may have a far larger problem with radioactivity. Our farmers are tipping huge quantities of uranium onto most of the fields that grow our food. It comes as a freebie with the phosphate fertilisers we make from marine rock phosphates.
According to the IAEA, (that is, the International Atomic Energy Agency), a regrettable waste in their view is that, at a conservative estimate, some 3,700 tonnes of hot uranium (un-depleted uranium, that is) is being lost to the nuclear industry and the arms dealers of the world, every year. That is how much they say could be extracted from the rock phosphate that now goes to make such fertilisers as super phosphate and triple super phosphate, if their industry was a little less slack. If the price of uranium went up, it could be leached out and saved, and though that was done in the past, it is not being done now. I leave it to you to decide if 3,700 tonnes of uranium spread over farm fields is a huge number or not. But for comparison, Little Boy, the bomb that spoiled life or cancelled it for so many people in Hiroshima, weighed 4,000 kilograms - four tonnes. There is another IAEA estimate that gives 7,500 tonnes of uranium going onto the world's farmlands, so if we say there is 4,000 tonne of it, given that commercial extraction would not get the lot anyway, that is probably a fair claim.
We are a bit short of phosphate deposits worldwide, and unlike oil and coal, there is no substitute at all for phosphorus in agriculture. It is central to photosynthesis and a shortage of it is the usual limit on all life forms.The normal background level for uranium in soils worldwide is about 2 parts per million (ppm) .Marine rock phosphates run at averages of about 50ppm to 120 ppm, with some organic phosphate deposits from Russia and nearby running at a rather warmish 600 ppm. The phosphate rocks pick the uranium up, over millions of years, from the passing groundwater. Uranium and phosphates just love each other, and so bond enthusiastically whenever they meet (Digital Journal, May 24, 2009 by Peter Ravenscroft ).
The World Bank invested 20 per cent of its total investment the agricultural development in Bangladesh since 1973. Being one sincere advocate of Green Revolution that introduced hybrid seeds supported by chemical fertiliser and pesticides World Bank in Bangladesh also continues to grant credit for many projects designed to promote and sustain Green Revolution. The World Bank (ADB, sister organisation of World Bank) has designed forestry projects which tend to put emphasis monoculture even in the mangroves in Bangladesh (Raj and Gain, 1997).
The food grain production in Bangladesh has been increased for which bringing more lands under food-grain cultivation worked as a major factor (Dhaka Courier, 17 October, 1997).In spite of introduction of “Green Revolution” half of Bangladesh’s population still reside under poverty line in regard to their ability to secure their food. This was revealed in a joint study called “Sustainable Food Security in Bangladesh” by Government of Bangladesh, UNDP and FAO. The study further found out that 25 percent of population live under extreme poverty line, 5 percent of which i.e. about 6.5 million people are “poorest among the poor” whose daily meal is always uncertain.
Agriculture in Bangladesh is directly supported by the chemical fertiliser production for which the World Bank has granted loan for several projects. So far the World Bank has granted credit directly for fertiliser production, import, transportation and fertiliser industry rehabilitation. The total World Bank credit allocation for this sector, within 1973 to February 1996 is US $ 166 million.
The World Bank works with the objective to promote private sector investment in agriculture and advises the government of Bangladesh to undertake policies accordingly. The Bank conducted studies between 1987-89 and identified constraints to the promotion of private investment in agriculture. It made suggestions to Bangladesh Government on how to make way for the private investment mainly for distribution of irrigation, equipment and import fertiliser and seeds which will enable the multinational corporate to spread the agri-business more in Bangladesh market (Dhaka Courier, 17 October, 1997).
World Bank Involvement in Ground water Withdrawal Activities:
Project Name BRD/IDA at Board* USD $ Million Approval Date Project Status Shallow Tubewell and Low Lift Pump Irrigation Development Project 75 30. 05. 91 Closed Deep Tubewells Project (02) 68 10. 08. 82 Cl;osed Hand Tubewells Project 18 5. 07. 81 Closed Low Lift Pumps Project 37 11. 03. 80 Closed Shallow Tubewells Project 16 16. 06. 77 Closed East Pakistan Tubewells Project 16 23. 06. 70 Closed Total 228
Subsequently, the government developed irrigation based agricultural strategy. These were policy reform projects towards private investment promotion – shallow tubewell, and low lift pump irrigation project completed in 1995 and National Irrigation Development Project in 1998. Accordingly, the Government of Bangladesh privatised the fertiliser distribution entirely in 1989-90.
The World Bank suggested that domestically produced fertiliser “should be priced in the line with world prices”. The aim is to encourage private distributors to sell fertiliser in domestic market. The World Bank never implied its influence in the Government to introduce quality control, environmental impacts on fertiliser use - like Federal Fertiliser Act (Canada, USA), EC Fertiliser Act that restricts uncontrolled harm to soil, water, biodiversity and human life. Green Revolution has contributed to the irreparable damage of natural biodiversity of the world, which is now well recognised by FAO and other international mainstream organisations working on food and one-time promoters of Green Revolution.
A.M. M. Shawkat Ali; Ministry of Agriculture, Government of Bangladesh (1987) made the following points on privatisation process:
A high level committee noted with great concern that the unplanned process of privatisation initiated by the World bank financed projects on the plea of rapid extension of irrigation facilities through private sector initiatives, has been counterproductive. The unplanned and unrestricted sale of Shallow Tubewells (STW), without adequate assessment of ground water availability and unsupported by an effective after-sale service system causing immense hardship to the farmers. This process has forced many farmers to sell part of their smallholding. Many farmers had to sell their cattle and even fruit-bearing trees to keep engines running. Ignorant farmers have to depend on so called dishonest “brokers” whose main job is to expedite loan sanction on payment of charges by the farmers. In cases, where the farmers are unable to pay the charges, these brokers, acting on behalf of the private turnkey contractors, usually paid the downpayment as a means of luring the farmers but actually recovered more than the amount of down payment made by providing less sinking materials against the total cost of the equipment to be borne by the farmers.
The IDA- financed projects failed to achieve project goals. As they have assumed that import of hardware alone would solve the problem of expanding irrigation. The largest majority of the STWs came to be owned by the affluent farmers. The other user farmers became bound by an informal agreement to pay per unit cost of irrigation to the “Water Lords”
About 40% of the fertiliser in Bangladesh are washed into the riverine and ground water systems (Safiullah and Mafizuddin, 1988). A recent study shows that a high concentration of ammonia (NH 4) and nitrate (N03) occur in the samples from shallow and deep tube wells (Hossain, 1997). The chemical fertilisers directly support agriculture, pesticides for which the World Bank has granted loan for several projects (the total credit for this sector from 1973 to February 1996 is US dollars 166 million). The growth rates of total rice production (the hero of our green revolution – HYV Boro) seems to have gone down and acreage during the last four years show a distinct downward move compared to the preceding period and to the decade’s average trend (Bayes, 1995).
In 1989 irrigated rice was produced in an area of 5944 000 acre which increased to 6709 000 acre in 1994-95. With the introduction of modern irrigation system traditional irrigation system decrease accordingly, at the same time more rich farmer became “Water Lords”, the poor farmers transformed to daily labourer or migrated to the cities slums.
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The farmers through manual lifting without any government investment irrigate about 30 percent of land But traditional method of irrigation is decreasing day by day, firstly the poor farmers are getting poorer due to sky rising unaffordable price of agrochemical, secondly due to modern power pumping and increase in deep tube wells there is scarcity in surface and shallow ground water. A. M.M.S. Ali (1987) of Ministry Agriculture, Bangladesh describes:
The mismatch of tubewells following the unplanned expansion of modern irrigation system, regardless of ground water potential, have limited future expansion of deep tube wells (DTWs, the deep tube wells are constructed primarily with imported, technologically complex pumps and engines of 56.6 l/s (2 cusses) or more and sunk by power rig)); at the same time the bunching of two types of wells, regardless of spacing criteria, have caused, in many places, drying up of Shallow Tube Wells (STWs, are locally constructed pumps and engines involving simple technology with less than 28.3 l/s (1 cusec) capacity, and are sunk by labour-intensive, percussion methods) and Hand Tube Wells (HTWs).. The donors are relentlessly pursuing the sale programme of DTWs. The current sale policy of DTWs to maximise irrigated areas is promoting the growth of “Water Lords”... Now the government is facing with the choice of declaring as many as 27,000 STWs engines as dead stock.
In 1979 Ghulam Mawla, Director, Bangladesh Water Development Board (BWDB) expressed disadvantages of ground water irrigation as the cost of developing water wells is greater than the cost of developing small streams.He adds (Mawla, 1979):
Recharge of ground water takes place during monsoon when irrigation is not required. As a result large quantity of water is carried to the sea as surface runoff and sub-surface flow. It has been found in the observation wells that during dry season water table goes down due to natural causes without any pumping. In the northern districts it has been observed that during dry season, the rivers are mostly fed by ground water, but due to long pumping of tubewells of Thakugaon Tubewell Project, the flow of river decreases or even dries up resulting failure of the low lift pumps.
According to a study by BRAC (Bangladesh Agricultural research corporation) 70 percent of Bangladesh total arable land has reached the critical level or has gone even below (BARC, 1993 study). Although the World Bank views that the damage has been caused by the “incorrect fertiliser application” (Dhaka Courier, Oct. 17, 1997).
In Bangladesh exists neither know-how on hazardous waste or laboratory facilities to analysis chemicals or substances that pose threat to human life, nature and soil.
Human communities have always generated, refined and passed on knowledge from generation to generation. Such “traditional” knowledge” is often an important part of their cultural identities. Traditional knowledge has played, and still plays, a vital role in the daily lives of the vast majority of people. Traditional knowledge is essential to the food security and health of millions of people in the developing world.
In industrial countries heavy metal contamination of agricultural soils, the impact on crops and on drainage the normal management mitigates water quality by the educated farmers. Practices such as periodic liming and maintenance of high surface organic matter levels, together with the generally better quality of agricultural soils – deeper, medium to fine textured, relatively high cation exchange capacities – tend, in most cases, to favour trace metal attenuation in the soil. In Bangladesh traditional agricultural practice that the farmers inherited since thousands of years replaced by agrochemical and so called modern “irrigation. system”. H. M. Khan, North West Hydraulic Consultant Ltd, Dhaka (1987) reveals that in planning or studies to find out the requirements of the farmers are totally neglected, mainly engineer’s decisions and designs are imposed on them although farmers posses the best source of hydrological and agricultural information. With the birth of “Green Revolution” flood embankments are constructed along either or both banks of the rivers which never protect severe floods but shallow normal floodwater. Farmer welcomes shallow flood that not only improves soil quality by depositing organic-rich silty-clayey sediments but also improves ground water condition during dry season. Flood embankments stop natural runoff monsoon rains and causes flooding.
Sir William Willcocks, an irrigation expert was extremely impressed by Bengal’s ancient system of flood (or overflow) irrigation, which eventually disappeared. In a series of lecture delivered in the 1920s, Wilcocks strongly argued that the ancient system should be revived in Bengal as it best suited the region and the needs of the people. The ancient irrigation system based on floodwater entered the fields through the inundation of canals, carrying not only organic rich silty sediments but also fish which swam through these canals (Khal) into the lakes (bil) and tanks (pukur) to feed on the larva of mosquitoes (Agarwal and Narian, 1997). According to Wilcocks, the ancient system of overflow irrigation has lasted for thousands of years. Unfortunately, during Afgan-Maratha war in the 18th century and subsequent British conquest of India, this irrigation system was neglected, and was never revived (Wilcocks, 1930). As Wilcocks reveals:
The delta of the Ganges is not a rainless area. It enjoys a rainfall of about 50 to 60 inches, when all rivers are in flood, and to make full use of the rich waters of the Ganges and Damodar floods and the abundant but nutritionally poor water of the monsoon rainfall that some early Bengal king put in practice the system of ‘overflow irrigation’ of the Ganges and Damodar deltas which insured health and wealth to Bengal hundreds of years. This system is perfectly suited to meet the special needs of Bengal.
Wilcocks observed “river water in the early months of the flood is gold” and made the following remarks when he spent sometime with the peasantry:
I have learnt from these men why they long for the old days when rice fields, tanks and pools were full of fish, which Bernier (an early English traveller) said, were in abundance. The peasantry craves for fish, which were the food for the poor in old days, which they seldom see today... Bernier saw in the 17th century that the overflow irrigation combated Malaria, provided an abundant harvest of fish, enriched the soil and made congestion of the river impossible.
In Bangladesh the government-constructed embankments that prohibit silt-laden flood water and monsoon rain does not drain the low pockets by gravity and caused return of mosquitoes and Malaria. In many areas farmers protests and cuts the embankments but the small rivers and canals (khals) are so heavily silted that the old system can not be reintroduced. We notice that after each severe flood when the rice fields are heavily flooded a bumper crop is yielded in following harvest season
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FAO reveals that land degradation costs South Asian states 10 billion US dollars a year due to damage in vital agricultural land that underpin food production: Afghanistan (33%), Bangladesh (75%), Bhutan (10%), India (25%), Iran (94%), Nepal (26%), Pakistan (61%), and Sri Lanka (44%) (Daily Star, 9. 3. 95).
The remarkable expansion of chemical fertiliser in the region has caused serious depletion essential plant nutrients. It has been appeared many areas in Bangladesh serious soil nutrient “mining” process and consequent decrease in yields. Fertilisers invented in the North (temperate climate) behave differently in tropical soils – many natural transformations are impossible to reproduce under existing laboratory or experimental studies. Now in Bangladesh 60 % of the arable lands have organic matter much below critical level (1.5 percent) and the rate of depletion is alarming. Over million hectare of arable land has been identifies as sulphur (S) deficient and two million hectare land has zinc (Zn) deficiency (Rahman, 1996).
Md. Reazuddin; Director, Department of Environment, Government of Bangladesh reveals (1992):
Due to the introduction of HYV technology in agriculture, the traditional land use pattern and cropping pattern of the country have changed, reducing the areas of wetland, and thus inland fishery and wildlife habitat. The low organic matter content, mineral deficiencies, higher cropping sequences and faulty management practices and agrochemical impact all combinedly have caused for a depletion of soil fertility. Submerged soils under irrigation increases the pH resulted depletion of essential minerals.
Approximately 80 percent of the total amount of arsenic that is released to the environment from anthropogenic activities that is released to soil (1982). The major anthropogenic sources contributing to arsenic in soils include the application of pesticides, disposal of solid wastes from fossil fuel combustion and industrial processes. Organoarsenical pesticides applied are metabolised by soil bacteria to form alkylarsines and arsenate. Historically, arsenic was used as insecticide in agriculture but increase environmental awareness and toxicity of arsenic most of the agricultural uses for arsenic were banned........ But pesticides based on arsenic is still produced or imported in the developing countries. At Behla, W. Bengal green plaster (arsenic based pesticide) is produced.
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UNDP (Development Transfer of Technology Series No. 13, Fertilizer Manual, UN, New York, 1980) reports:
The safe disposal of solid wastes or by-products from fertiliser plants has been problem particularly in developed industrial countries. Phosphogypsum is by far the largest by-product in the manufacture of “wet- phosphoric” acid. For every ton of P205 produced, 5 tons of phosphogypsum must be disposed of. Another solid waste is produced in Vetrocoke (potassium carbonate) processes for eliminating carbon dioxide in the manufacture of ammonia. The sludge contains 20% arsentrioxide As203.
As it has been seen TSP fertilisers used in Utter Pradesh, India contains 187.8 mg/100 gm arsenic (Kukal, 1978) is an extremely hazardous waste possibly due to the addition of solid waste during the manufacture of “wet-phosphoric”, sludge containing arsenictrioxide or others. It is likely that same kind of phosphate fertilisers were used in India and Bangladesh. Dishonest manufacturer and traders can also add contaminated sludge that contains 20% arsenotrioxde. Prof. Khaliqur Rahman, Chemical Engineering Dept, BUET, Bangladesh (1992) reveals:
A much serious problem is the disposal of highly toxic waste sludge from HFFG that has accumulated in the factory from carbon dioxide absorption tower. It has estimated that well over 22,000 CFT of packing material along with sludge containing arsenic has piled up. The arsenic control in the sludge is about 40 %. The process has since been modified and arsenic is not used in the absorbing solution, but large quantity of solid material remains dumped in concrete pit and in the open.
In Bangladesh everything is sold in the market. Author observed PCB containing oils from the so called “ship- breaking” industry in Chittagong is sold all over Bangladesh as lubricant for brick burning industry and as “Maitah Tel” (soil oil) found in the grocery shops. It is likely that much of the waste from the fertiliser industries from home or abroad ultimately landed to the rice fields, which the poor farmers have to buy it that cost them sweat, blood and tears.
A.T. Khandakar, Department of Environment, Govt. of Bangladesh (1992) reports on low cost fuel import in Bangladesh:
International racketeering was going on then regarding transboundry movement and disposal of these types of hazardous waste. At the time, one American ship laden with wastes was floating in the sea failing to dump the wastes in Nigeria. The industrially developed countries were trying to export their hazardous wastes to the developing countries due to high cost of treatment in their own countries to get rid of their own pollution problems. It was not unlikely that the wastes imported by the said promoters would clear up the unavoidable wastes of the western countries in the form of low cost fuel source of the said industry in Bangladesh. Since the wastes would be carried in sealed container they would be beyond the checking of custom officials in Bangladesh. Even if none for looking after due to lack of monitoring equipment and surveillance activity for the same in Bangladesh.
Every day one million tonnes of hazardous wastes are generated in the world, 90% of them in the industrialised world (Meadowset, 1989). The developing countries have become a direct and indirect dumping ground of hazardous wastes of industrial countries For example EC has safe disposal facilities for only 10 million tonnes of hazardous waste per year, or one-third of the total generated. Twenty million tones of hazardous waste per year will be looking for a resting-place.
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Cow dung is the latest culprit found to be causing arsenic poisoning in unsuspecting villagers in West Bengal, India.
During the last century people living in China, Nepal, India and Bangladesh were encouraged to use well water rather than surface water. Whilst reducing the number of casualties from bacterial diseases, it was soon discovered that the well water is contaminated by arsenic leaching from rock. Sickness through drinking the well water and rice, and other crops, irrigated with contaminated water has been widely reported. Dipankar Chakraborti and colleagues from Jadavpur University, India, have now discovered another related route through which people in West Bengal are exposed to arsenic. Chakraborti explains that in this region cow dung, from cows fed contaminated rice straw, is dried in the sun and used as fuel in domestic ovens. He found that when the cow dung cakes are burnt arsenic is released into the air, which is then inhaled.
Jose Centeno, an expert in medical geology at the US Armed Forces Institute of Pathology in Washington, DC, said the findings are important as they describe yet another previously unknown source of arsenic exposure in this region. The exposure is magnified because the ovens and kitchens are not ventilated, said Chakraborti. He explained that woman and children in the region are the worst affected because they spend an average of seven hours a day next to ovens. Inhalation of arsenic leads to respiratory problems such as persistent coughs and reduced lung capacity, said Chakraborti. Centeno believes that a concerted effort is needed to prevent further communities being exposed to arsenic. He said that geoscientists are currently 'trying to determine the source rocks from which arsenic is being leached' and to determine what caused the arsenic to be mobilised from the rock. (Chemical Science, Volume 2007 11, October 5, 2007).
The fact that people are not only exposed to arsenic through ingestion of water and food but also inhalation adds to the danger, the researchers wrote.
New research suggests that cow dung used by millions of people in India in cooking fires may be adding to the arsenic poisoning epidemic.
“This is a very interesting study that illustrates the need to be creative to try to find all the potential exposure pathways,” says Geoff Plumlee, a geologist with the U.S. Geological Survey in Denver, Colo. “Once you think about the fact that arsenic is in straw and water consumed by cattle, it makes a lot of sense that the burning of cow dung is something that needs to be looked at.” The authors also point out that arsenic from combustion could accumulate in food and water, potentially concentrating an additional source of arsenic not accounted for by inhalation alone. This is an important factor to consider, Plumlee says, adding that work in China has shown that consumption of chili peppers and corn dried over hearths burning arsenic-rich coal is a very important exposure pathway. “Arsenic is liberated during the coal combustion and ends up depositing on the chili peppers and corn, which are then consumed.”
Plumlee adds that more detailed studies are needed to find out how arsenic is transformed through cow dung combustion and what form it assumes once it is released into the air. “The form of the arsenic strongly affects toxicity,” he says. For example, organic arsenic compounds are generally considered less toxic than inorganic arsenic compounds. The form determines how the body takes up the arsenic, for example, whether the lungs readily absorb it after inhalation or whether it gets trapped in the mucus and swallowed, Plumlee says. “This innovative study certainly raises intriguing questions about a previously understudied potential exposure pathway for arsenic,” he says (Nicole Branan, Geotimes, January, 2008).
Additional danger of arsenic exposure through inhalation from burning of cow dung cakes laced with arsenic as a fuel in arsenic affected villages in Ganga–Meghna–Brahmaputra plainIn arsenic contaminated areas of the Ganga–Meghna–Brahmaputra (GMB) plain (area 569749 sq. km; population over 500 million) where traditionally cow dung cake is used as a fuel in unventilated ovens for cooking purposes, people are simply exposed to 1859.2 ng arsenic per day through direct inhalation, of which 464.8 ng could be absorbed in respiratory tract (J. Environ. Monit., 2007, 9, 1067 - 1070, DOI: 10.1039/b709339j. br> Top of page
In 1992 Bangladesh Agricultural Development Corporation (BADC) obtained a credit from the Asian Development Bank to import fertiliser from the USA. Stoller Chemical Company in association of Gaston Copper Recycling Co, and South Wire Corporation of USA exported 6300 metric tonnes of fertiliser to Bangladesh. This fertiliser contained extremely hazardous heavy metal concentration that exceeds thousand times allowable level. Since there is no controlling mechanism exists in Bangladesh, the first shipment of the fertiliser was distributed uncontrolled to the farmers. As the second shipment arrived Bangladesh, Green Peace and other environmental organisations made a heavy protest by disclosing the content of the fertiliser, but 4,164 metric tons of poisonous fertiliser was already distributed. It was known that hazardous waste from the Smelter Furnace Dust was mixed with the fertiliser.
Later on November1, 1993 a District Federal Court of South Carolina, USA fined Gaston Copper Recycling and South Wire Corporation a penalty of one million U.S. dollars for mixing hazardous waste in fertiliser. But the farmers of Bangladesh were never compensated and the irreversible harm to soil and water perhaps just continued as in the unrecorded past.
The daily Sangbad on January 12, 1995 reports that Brighton Company of Khulna imported 3000 tons of TSP (Single Super Phosphate) fertiliser from India containing abnormal appearance of coloured material with TSP fertiliser. The prescribed phosphate content was absent. Analysis on hazardous material was not performed. Farmers protested the loss of their crops but nothing substantial was done on quality control, loss of property, environment and health of the rural population of Bangladesh.
No body knows the fate of uncontrolled hazardous waste that can arrive Bangladesh in any form. If the soil and water could speak, could not be able to say as thousands of unnatural complex chemicals are produced each day without knowing its final resting-place.
What are the contents of other imports that have began since the sixties?
There are numerous reports of hazardous fertilizer sold in the market but the Agricultural Departments are incapable to trace content of the hazards. The cheap toxic fertilizers are easily sold in the market. An example of a recent publication in Independent (December 8, 2003):
Spurious fertilisers on sale in Noapara, Jessore (arsenic affected area)
Dec 7, 2003 : Spurious fertilisers are being sold by a section of dishonest fertiliser traders of Noapara industrial area, the biggest cement and fertiliser sales centre in the south-western region of the country. These dishonest traders not only market but also produce adulterated fertilisers in huge quantities. The retail fertiliser traders from different districts of Khulna division and North Bengal buy these spurious fertilisers and sell those to the farmers of their respective areas. By using these harmful and poisonous fertilisers the farmers of those areas are being cheated. They cannot produce crops up to their expectations as the adulterated fertilisers spoil the fertility of their lands.
The lion's share of the adulterated fertilisers remain undetected and the dishonest businessmen sell those to the traders of different districts. Different fertiliser importers of Noapara have reportedly imported huge quantities of harmful FMP fertiliser from abroad and stored in their godowns. The other godowns belonging to Baghdad Trading and those of other importers contain huge quantities of inferior quality FMP fertiliser and prohibited Indian fertiliser worth crores of Taka, sources at Noapara said. It is also learnt that the importers at Noapara import two kinds of FMP fertiliser from abroad. They sell one kind of FMP at Tk 350 per bag and the inferior and spurious category of FMP is sold at Tk 300 per bag. The cheaper category of FMP is harmful and poisonous.
The farmers of the 26 districts of the south-western and northern regions of the country are being cheated by purchasing and using the inferior quality FMP fertiliser in their crop fields. It is alleged that the adulterated FMP fertiliser does not dissolve. As a result, fertility of soil is lost. The particle fertiliser is harmful for soil and causing loss to the innocent poor farmers.
High Court bans entry of 'toxic' ship
A Bahamian-registered ship that environmentalists say is "toxic" and was due to be dismantled in Bangladesh has been banned from entering its territorial waters by the High Court, lawyers said yesterday.
Alfaship, which arrived in the outer anchorage of Chittagong Port, is one of 50 ships on a "watch-list" of vessels being monitored by Greenpeace. The High Court issued the ruling yesterday after the Bangladesh Environment Lawyers Association (Bela) challenged the legality of the vessel's entry into the country's waters.
"The court banned the ship from making any further move into Bangladeshi territorial waters for two months," Bela Executive Director Rizwana Hassan told AFP. Greek-managed LSP Tanker Corporation which owns the ship said yesterday that standard industry "decontamination" procedures had been carried out before the vessel left a port in Greece.
"Prior to commencing her final voyage, the Alfaship was made gas free and emptied of oil cargo residues," company spokesman Nicholas Brown said in a statement. "Alfaship is no different from hundreds of tankers and other merchant vessels sold for demolition in Bangladesh, India and Pakistan in recent years. "The fact that the ship appears on a list on the website of Greenpeace appears to be completely arbitrary," he added.
The company said it would continue to cooperate fully with the Bangladeshi authorities to ensure it met all its requirements. The High Court ban follows a temporary order last week by the Bangladesh government's Mercantile Marine Department refusing permission for the oil tanker to be scrapped. "The entry of Alfaship is illegal because it's a toxic ship," Rizwana Hassan told AFP earlier, without elaborating. The Bangladesh government has not given any detailed reasons for refusing permission for the vessel to be scrapped.
Shipbreaking yards in Bangladesh dismantle up to 80 ships, mostly oil tankers, each year. The metal is sold for recycling into iron rods for construction and other purposes. Operating on beaches at Sitakundu the yards directly or indirectly employ 300,000 people. Workers break up the ships manually without safety equipment. The United Nations Development Programme says accidents that kill or maim shipbreakers are "not uncommon" (Afb, Daily Star, May 4, 2006).
It is very common to see that thousands reports published in district news on adulterated and spurious fertilizers since two decades but no action was taken by the controlling ahthorities.
Fertilizer Risk in the USA
Concerns have been raised regarding the use of certain wastes in the manufacture of agricultural fertilizers and soil amendments, and the potential for ecological or human health risks, as well as crop damage, when such fertilizers are applied to farmlands. In conjunction with state governments, the U.S. Environmental Protection Agency (EPA) has launched a major effort to assess whether or not contaminants in fertilizers may be causing harmful effects, and whether additional government actions to safeguard public health and the environment may be warranted.
The U.S. Environmental Protection Agency's (EPA's) fertilizer risk assessment uses existing and available data to estimate potential risks posed to human health and the environment by contaminants in fertilizers. The primary purpose of the fertilizer risk assessment is to inform the Agency's decisions as to the need for federal regulatory action on fertilizer contaminants.
Several studies have measured heavy metals in mineral ores and the resulting fertilizers. Natural rock phosphate ore contains zinc ranging from 0.2 to 576 mg/kg and measurable amounts heavy metals.These metals can also be found in the NPK fertilizers that are produced from natural ores.
"No person shall distribute an adulterated fertilizer product. A fertilizer shall be deemed to be adulterated:
If it contains any deleterious or harmful substance in sufficient amount to render it injurious to beneficial plant life, animals, humans, aquatic life, soil or water when applied in accordance with directions for use on the label, or if adequate warning statements or directions for use which may be necessary to protect plant life, animals, humans, aquatic life, soil or water are not shown on the label." Consistent with the AAPFCO model fertilizer bill, most states currently have a general prohibition on distribution of “adulterated” fertilizer products.
In 1928, the German chemist, Fredrich Wöhler made an unexpected discovery that he was able to synthesise for the first time an organic compound, urea. Wohler’s accidental discovery proved to be a major turning point in the history of science and industrial technology. The use of industrial chemicals had widened greatly by the beginning of World War I, but the greatest increases in chemical production came during World War II. During the 1960s and 1970s, large-scale Western agricultural technologies were introduced to many traditional farming societies in the Third World countries – the so-called “green revolution”. The green revolution since its birth has been advocated and decorated with all the attributes that should feed the hungry population of Africa and Asia – just like DDT that was crowned with “noble-prize”.
Pollution through agrichemicalsSeveral studies have shown that heavy metals are present in the parts per million (mg/kg) range, and occasionally as high as parts per thousand, in fertilisers produced from recycled industrial by-products (US EPA, 1997).
Banned Pesticides in Industrial countries but allowed for export:
- arsenic trioxide
- 4. 2,3,4,5-Bis(2-butylene)tetrahydro-2- furaldehyde [Repellent-11]
- bromoxynil butyrate
- cadmium compounds
- calcium arsenate
- carbofuran (granular only)
- copper arsenate
- lead arsenate
- sodium arsenate
- sodium arsenite
Thirty-eight percentage of international trade in pesticides in 1978 occurred in the developing countries pesticides. According to a report by the US Congress’ General Accounting Office, 30 percent of all pesticides exported from the United States were unregistered – that is, not approved by the Federal Environmental Protection agency – for use in the United States. A pesticide produced solely for export need not be registered with EPA. Prior to 1978, it was possible to begin manufacture and widespread distribution of a pesticide outside the United States without even informing the EPA, and over 85 million pounds of such unapproved pesticides were shipped abroad in 1975 (Norris, et al., 1982)
Dhaka Courier on 26th January 1996 reports that no measures have been taken to withdraw dangerous and pestiferous insecticides from the market despite a warning by the World Health Organisation (WHO). Nuruddin (1996) reveals on the adverse effects of pesticides, firstly because of the lust of a section of businessmen, the ignorant, illiterate and naive farmers suffering physically by using these “unnamed insecticides” and secondly damage is caused to the soil, water, fish resources and environment and the country is facing a kind of indirect chemical warfare, Nuruddin (Dhaka Courier, 26 January 1996) further adds:
The “no name” pesticides are entering in the country in jerry and cans without any brand name or label and are sold in the rural areas at a lower price. A gang brokers has been supplying these unnamed insecticides to retail sellers very secretively for last three or four years. And the retail sellers, not knowing the consequences, have been selling these insecticides to the innocent farmers at a low price, which is the main attraction. The sellers and the buyers do not know the names of these insecticides. These insecticides have a common popular image, that they have long lasting effects. Where the government approved pesticides need to be used more than once, these particular insecticides have one time use only. Such insecticides are sold at Tk 50 (1 US dollar) per litre whereas other pesticides cost Tk. 200 to 250 per litre... The unnamed pesticide is extensively in use in villages in districts of Lakshimpur, Satkhira, Naogaon, Chuaganga, Jessore and Jhenidah (Now these areas are the worst arsenic contaminated areas of Bangladesh; Anwar, 2000)... Some pesticide marketing company took initiative to locate the pesticide and drew the attention of local plant protection officials. But unfortunately the plant protection department did not take any initiative to collect samples and test to verify the allegation of containing toxic chemicals... Thiodan, Thionex and Zinc Phosphate and others come from India. . At present 8000 metric tons of pesticides are being used in Bangladesh and most of them bear red level (very dangerous poison).
AbuTaleb Khandakar (1992), Department of Environment, Government of Bangladesh reports nearly 5000-6000 MT pesticides are used in Bangladesh and numerous unauthorised products:
There are numerous pesticide products that are formulated by local unauthorised companies. These products are notorious for being adulterated and many do not have levels. One such unlabeled commonly referred to as “silver dust” is reputed to be highly toxic. Thiodan, not registered in Bangladesh is commonly smuggled across the Indian border. It is known to be both unlabeled and adulterated with DDT.
Arsenic is an elemental metal used in insecticides, herbicides, and manufacturing processes (Coffel, 1989). Arsenic is used extensively in insecticides as calcium arsenate to boll-weevil in cotton fields, and in herbicides and plant desiccants as lead arsenate to control codling moth, plum curculio, cabbage worm, potato bug, tobacco horn worm, and other pests that attack fruits and vegetables. Many thousands of As (+3) and As (+5) compounds with carbon-arsenic bonds have been synthesised and tested for their effectiveness against various agricultural pests. Methyl arsenic and dimethyl arsenic or salts are extensively used for weed control. Phenyl arsenic acid, cacodylic acid, methane arsenic acid and Lewisite ( CH3-CH =CHAsCl2) as a chemical warfare agent, are some of the well-known and widely used arsenicals (Moore and Ramawiorthe, 1984). The toxicity of arsenic compounds is different from those of heavy metals. For arsenic the toxicity to the rat declines with arsenite ? arsenate ? methyl arsenate = dimethyl arsenate. The toxic dose increases by about fifty between arsenite and methyl acid salts. The toxic effects appear to be caused by binding to sulphydryl lipid groups by trivalent arsenic, and pentavalent arsenic appears to be reduced to the trivalent form (Harrison, 1990). Green Plaster produced in India is very likely to enter Bangladesh as “no name “ pesticides
Effects of Pesticides on Living Organisms:
Cancers, tumors and lesions on fish and animals, possibly death. Reproductive inhibition or failure. Suppression of immune system, and/or disruption of endocrine (hormonal) system, and in general poor fish health marked by low red to white blood cell ratio. Cellular and DNA damage. Teratogenic effects (physical deformities such as hooked beaks on birds). Intergenerational effects (effects are not apparent until subsequent generations of the organism). Other physiological effects such as egg shell thinning.
Potential Sources of Ground Water Contamination (US EPA; 2000):
Agriculture :Crop-related sources , Irrigated crop production, Non-irrigated crop production, Specialty crop production (e.g., horticulture, citrus, nuts, fruits), Grazing-related sources* Pasture grazing - riparian and/or upland
Intensive animal feeding operations, Concentrated animal feeding operations (CAFOs; permitted; PS) Confined animal feeding operations (NPS)
Aquaculture , Atmospheric deposition,Collection system failure
Combined sewer overflow Construction , Highway/road/bridge construction, Land development ,Contaminated sediments,Debris and bottom deposits Domestic wastewater lagoon
Groundwater loadings , Groundwater withdrawal
Habitat modification (other than hydromodification), Removal of riparian vegetation
Bank or shoreline modification/destabilization , Drainage/filling of wetlands
Highway maintenance and runoff
Hydromodification , Channelization, Dredging
Dam construction , Upstream impoundment , Flow regulations/modification
Industrial Point Sources , Landfills , Inappropriate waste disposal/wildcat dumping* , Industrial land treatment Onsite wastewater systems (septic tanks)* , Hazardous waste etc.
One of the routes of mercury pollution is through the use of pesticide containing mercury.”
A GROUP of researchers from Kolkata’s Vivekananda Institute of Medical Sciences claims that exposure to mercury can bring about lethal effects on human peripheral white blood cells. In a lab dish, the team has shown that even a minute amount of mercuric chloride, an organic salt of mercury, can damage the chromosomes of human white blood cells. “The study results suggest that tracking down the harmful chromosomal changes in peripheral white blood cells is a good biomarker in assessing the risk of mercury toxicity-induced cancer in humans,” says Ajanta Haldar of VIMS, who led the research team. “Recent reports indicate that mercury concentration in various soil samples from the eastern part of India is much higher than the level prescribed by World Health Organisation,” he says. “One of the routes of mercury pollution is through the use of pesticide containing mercury.”
ndustrial waste is also a factor in increasing mercury load in soil and water. Chlor-alkali industries are still the major source of mercury release in atmosphere and surface water. Other industries that contribute to mercury pollution in India are petrochemical complexes, fertiliser factories, oil refineries, pulp, paper, textile, sugar and steel mills, tanneries, coal washeries, synthetic material outlets, and plants for drugs, fibres, rubber, and plastics. “A Chlor-alkali factory in Khardah, West Bengal, has been accused of discharging mercury in its effluents,” says Haldar, adding that “high levels of mercury have also been observed in the effluents discharged from a chemical fertiliser factory in Meendweep Island of Haldia in West Bengal”.
This is alarming given that mercury is a potent neurotoxin. Even at extremely low levels of exposure, it can cause permanent damage to the human central nervous system. Methyl mercury, a compound of mercury, damages the developing brain and causes permanent damage to the central nervous system, lungs and kidneys, thus posing a grave danger to unborn babies. To study the toxic effects of mercuric chloride on peripheral human white blood cells, the VIMS team cultured human white blood cells culled from peripheral venous blood of normal healthy blood donors in the age groups 1-12, 13-24, 25-36 and 37-48 years. When the cultured white blood cells were exposed to three different doses (5.4, 0.54 and 0.054 microgrammes/ml) of mercuric chloride solution for 72 hours, they showed abnormal cellular changes. Among these three doses, 5.4 microgrammes/ml, which is one-hundredth of a lethal dose (for lab studies), was found to be more toxic and .054 microgrammes/ml the least.
At lethal dose (one hundred times 5.4 microgrammes/ml, also for lab studies) of mercuric chloride, blood cells showed a greater number of damages. The chromosomes became clustered in the centre of the cell as dense lumps,” Haldar and her colleagues wrote in the August issue of the Indian Journal of Experimental Biology. Research across the country pours out eye-popping results. Some of the major rivers tested for heavy metals by the Industrial Toxicological Research Centre, Lucknow, were found to contain mercury in alarming levels. Testing of seawater by the National Institute of Oceanography, Goa, found increased mercury concentrations in the Arabian Sea. Several studies on fish and prawns in Mumbai, Kolkata and in parts of Orissa, have reported alarming rates of mercury concentrations. A recent study conducted by the Environmental Science Department of the Guru Gobind Singh Indraprastha University, Delhi, has revealed that the concentration of contaminants like arsenic, mercury and nitrates in the groundwater of Delhi exceeds the permissible limits. The study entailed 50 samples of groundwater lifted from random spots along a 22-km stretch between Palla and Okhla in Delhi.
The mercury concentration in some samples was as high as 4.6 ppm. This alarming presence of mercury in groundwater can be traced to the continuous discharge of sewage and industrial effluents into the Jamuna and, subsequently, into the groundwater aquifer which, being sandy in nature, allows mercury pollution to spread at a rapid rate. Other studies have also shown mercury’s toxic effects. According to a study released in October 2004, conducted by the University of North Carolina, 21 per cent of women of childbearing age had mercury levels in their hair that exceeded federal health standards.
Dr Kathryn Mahaffey, a biochemist with the USA-based Environmental Protection Agency, estimates that one in six pregnant women in the USA has high enough blood mercury to damage her child. Developed countries have risen to the occasion. Europe has decided to phase out all its mercury-based plants. It has over 13,000-18,000 tonnes of mercury that it will dump. The USA also has excess mercury stocks. Unfortunately, India is yet to wake up to the warning signals given by researchers. Instead, it continues to be a dumping ground for mercury containing wastes.
Over the past seven years, Europe has sold over 3,000 tonnes of this toxic substance to India. In most cases in this country, the contamination level in fish exceeded the 0.5-ppm (parts per million) total mercury regulation. In the west coast, particularly in Mumbai, it was 1.6 times higher than the permissible level.
All of this paints a grim future that looms large on posterity. Before it is too late, we should pay heed to the findings of researchers like Haldar. Or else we may all fall victim to mindless activities (The Staesman, Sept. 11, 2005).
Arsenic in Bangladesh drinking wells may be linked to crop irrigation, MIT study finds
A ruthless killer in Bangladesh's drinking water is making millions of people sick and may be causing as many as 3,000 deaths each year. That killer--naturally occurring arsenic in the water drawn from family wells--appears to have been released through a process involving crop irrigation, at least in one part of the country.
At a research site in the southern part of Bangladesh, scientists calculated that irrigation pumping, which began in the last several decades, has dramatically altered groundwater flow through the aquifer. They show that the resulting changes to the chemistry of the groundwater have the potential to either increase or decrease arsenic levels, in a paper written by an MIT-led team of scientists in the Nov. 22 issue of Science. "Our data indicate that the arsenic was mobilized largely by degradation of dissolved organic carbon by microbes. Some of the organic carbon appears to have been drawn into the aquifer by irrigation pumping," said Charles F. Harvey, assistant professor of civil and environmental engineering at MIT and lead author of that paper. "But the effects of irrigation are complex, probably lowering arsenic concentrations in other areas. Curtailing irrigation pumping is not a solution."
Harvey is also an author of a research paper providing an epidemiological analysis of arsenic-induced illness throughout Bangladesh. That paper will appear next year in the Water Resources Research journal published by the American Geophysical Union. In it, the authors conclude that replacing 31 percent of the country's most tainted wells with deeper wells will eliminate about 70 percent of the illness, assuming that arsenic levels remain low in the deep wells.
Arsenic poisoning, usually characterized by sores on the chest, or blackened knotty palms, and cases of skin, lung, liver, bladder and pancreas cancers have been linked to arsenic in the drinking water. In 1998 the World Bank agreed to provide Bangladesh a $32.4 million credit to develop a method of controlling the arsenic. But today, most Bangladeshis continue to drink arsenic-laced water. The World Bank describes the problem as one of the world's primary environmental challenges. The World Health Organization refers to it as "the largest mass poisoning of a population in history" in a fact sheet published in March.
The mass poisoning began, sadly enough, with a well-meaning attempt to provide clean drinking water for Bangladeshis, who suffered from cholera and other diseases caused by bacteria in water taken from surface reservoirs. To remedy that problem, the Bangladesh government, with the help of international aid organizations, drilled between 6 and 10 million wells at depths ranging from 50 to 300 feet to provide clean, safe water for individual households.
At about the same time, farmers in this largely rural country began irrigating land so that rice, the country's main food staple, could be grown during all six of the dry months when monsoon flooding abates. Cholera deaths dropped. But about 10 years into the use of the tube wells, villagers started displaying symptoms consistent with arsenic-related illnesses, and incidents of skin cancer and internal cancers became common.
Harvey's team used radiocarbon dating to determine the age of the carbon isotopes in the groundwater at various depths. They found that very young and very old carbon were mixed, and concluded that water had carried young organic carbon (probably derived from untreated waste on the surface) deep into the aquifer (MIT, Nov. 21, 2002).Top of page
The most intractable hazardous wastes are human- synthesised chemicals. Since they have never before existed on the planet, no organisms have evolved to break them down and render them harmless. A total of 65,000 chemicals are now in regular commercial use. Toxicology data available on less than 1% of them. According to a report the U. S. Congress’ General Accounting office, 30 percent of all pesticides exported from the United States were unregistered – that is, not approved by the Federal Environmental Protection Agency – for the use in the United States. The chief exporters of pesticides are companies based in Germany (25%), U.S.A. (20%), United Kingdom (15%), Switzerland (15%), France (13%), Japan (5%), and Italy (3%) Norris, 1982). Many pesticides that are forbidden in these seven countries due to hazardous consequences but are exported to developing countries. Abuses, exploitation of uninformed hungry consumers, and the double standard that says products considered for use in the industrialised world may be promoted and sold freely in the developing nations – are the issues confronting basic values and morals of the industrialised countries.
Adulterated fertiliser floods market for lack of control
With no specific body given the responsibility for ensuring quality of fertilisers - a crucial input in agriculture - there are virtually no quality control measures in the country. Consequently, thousands of farmers are tricked into buying adulterated and ineffective fertilisers. Private operators, selling supposedly imported fertilisers including Triple Super Phosphate, Single Super Phosphate, Zinc and Boron, often dupe farmers with sub-standard and locally produced adulterated fertilisers.
An official of the Bangladesh Agricultural Development Corporation alleged that although the corporation has laboratories for testing fertilisers that is ready to go into operation, the special inspection committee of the ministry has been delaying its approval for eight months. The committee have apparently failed to cite their reasons for the delay and the corporation has not yet received approval for testing fertiliser quality.
Despite a government decision, notified by the Bangladesh Gazette on November 22, 1999, stipulating that the Bangladesh Agricultural Development Corporation must be authorised for fertiliser management including implementation of the fertiliser control order, quality control and test, the agriculture ministry did not approve the corporation as dictated by the gazette.
Some local companies in Jessore, Bogra, Chittagong and Narayanganj produce these substandard fertilisers, often mixed with rubbish and soil, as the nutrient fertilisers sell at a higher price. These companies produce zinc, potash, boron and SSP, which have no certificates ensuring their quality. An agriculture official from Jessore admitted that particularly in Jessore and Noapara dealers were selling adulterated and substandard SSP and Fused Magnesium Phosphate as TSP. Some dealers also sell Indian SSP and FMP as TSP, which sells at a higher rate according to the official.
He said usually zinc sulphate contains 36 per cent zinc, but the fertiliser produced in Jessore and Jhenidah contain hardly 3 to 4 per cent zinc. About 60 to 70 per cent substandard zinc sulphate is likely to be used in the southern and northern regions including Jessore, Jhenidah, Meherpur and Chuadanga. Besides this, there are three types of widely used boron fertilisers - boric acid, flover and borax. Although the original boron is supposed to contain a minimum of 17.5 per cent boron compound, the locally manufactured fertiliser has only 2 to 3 per cent boron.
Sources concerned alleged, "Only 5 to 7 fertiliser factories in these areas are approved by the Department of Agricultural Extension, but there are 100 to 150 factories operating without approval." Another agriculture officer from Jessore told New Age, "Usually the original zinc fertiliser sells at Tk 30 per kilogram, but currently it is selling at prices between Tk 8 and Tk 10." According to a report of the Bangladesh Agricultural Development Corporation on "the role of soil health, quality fertiliser and good seeds for adequate food production", the markets are rife with adulterated fertilisers deficient in the required plant nutrients.
The total fertiliser demand in the country is 42.5 lakh tonnes - with 26 lakh tonnes of urea and other fertilisers making up the remaining 16.5 lakh tonnes. The other fertilisers include 5 lakh tonnes of TSP, 3 lakh tonnes of DAP, 4.5 lakh tonnes of MOP. The locally manufactured fertilisers are 1.25 lakh tonnes of SSP, 1 lakh tonnes of NPKS or mixed fertiliser, 1.5 lakh tonnes of gypsum, 25,000 tonnes of zinc and 5,000 tonnes of boron (New Age, November 6, 2004).
Fake fertilizer and pesticides factories are growing like mushrooms in the country.
Fertilisers 'reducing diversity'
Scientists have identified why excessive fertilisation of soils is resulting in a loss of plant diversity. Extra nutrients allow fast growing plants to dominate a habitat, blocking smaller species' access to vital sunlight, researchers have found. As a result, many species are disappearing from affected areas.
A team from the University of Zurich, writing in Science, warned that tighter controls were needed in order to prevent widespread biodiversity loss.
Estimates suggest that the global level of nitrogen and phosphorous available to plants has doubled in the past 50 years. Looking at grasslands, the researchers said it was widely recognised that an increase of chemical nutrients in an ecosystem led to a loss of diversity, but the mechanism of how it was occurring had been difficult to determine. "You would think that more [nutrients] would lead to more biodiversity," said co-author Andrew Hector, a researcher at the University of Zurich's Institute of Environmental Sciences. "Yet it is considered to be one of the main threats to biodiversity this century."
Professor Hector explained that there were two main hypotheses: "One is that the presence of more resources led to a general increase in the strength of competition among plants. "The other is a little bit more mechanistic," he told BBC News
"When you get an increase in fertilisation, you get an increase in productivity, leading to increased plant biomass and increased shading. "This shifts the idea to light being the critical resource, with shorter species being shaded out by taller species, resulting in a loss in diversity."
The findings led the team to conclude that it was the lack of access to light that affects diversity, not an increase in the strength of competition. "We have done the critical experiment that has been asking to be done for the past 35 years," said Professor Hector. "If it all depends on light levels, then if you put the light back then you should prevent a loss of biodiversity." However, he added that their findings did not offer a "magic bullet" for conservationists. "What our research shows is that competition for light is very asymmetric. "So if a plant can get between the sun and its competitors, not only can it get all the light it needs but it can also block its competitors' access to light.
"Because this competition for light is such a 'winner takes all', it emphasises how important it is that we control nutrient enrichment." (Source: BBC, May 01, 2009).
Spurious fertilizer factory unearthed in Jhenidah
JHENIDAH, Feb 16:–Agriculture Minister MK Anwar unearthed an spurious fertilizer factory at Bishaikhali bazar under Jhenidah sadar upazila and handed over three of the factory to the police. A case was filed against them on Saturday. The local people brought to the notice of the Minister about the spurious fertilizer factory Bishaikhali bazar when the minister was taking to the local people on way to Jessore on Saturday afternoon. Later the minister unearthed the spurious factory and ordered the Jhenidah district administration to seal the factory and handed over its there propritors Alamgir Hossain, Abdul Gafur and his brother Khokon to the police. He also ordered them to file a case in this connection. But no case has been recorded, the police said. It may be mentioned here that at least 15 unscrepulous spurious businessmen manufacturing adulterated fertilizer in their spurious factory and marketing the adulterated fertilizer in different markets of Jhenidah district and its adjoining areas (The bangladesh Observer February 17, 2005).
Low-quality, adulterated fertilisers flood market - (Arsenic contaminated?) 2005
Low-quality and adulterated fertilisers have flooded the market in the absence of implementation of the Fertiliser Control Ordinance 1999. Reluctance of the Department of Agricultural Extension officials in monitoring the quality of fertiliser and taking action against the producers of substandard and adulterate fertilisers are blamed for the non-implementation of the ordinance. Allegations are also there against the DAE officials that they remain blind by taking bribe from the producers of the low-quality fertilisers, also encouraging the growth of the fake factories.
Also, inactivity of the district and upazila-level monitoring committees on seed and fertiliser are blamed for the adulteration and production of substandard fertilisers, and their marketing.
Fifty-six per cent of the fertiliser tested in 2004-05 by the Soil Resource Development Institute was found adulterated. The institute examined 800 samples of different types of fertiliser collected from different markets of the country, the SRDI sources said.
In 2003-2004, SRDI tested samples of 63 varieties of fertiliser, including TSP, SSP, DAP, zinc-sulphate, fused magnesium phosphate, MOP, sulphate of potash and NPKS or mixed fertiliser, and found 100 per cent adulteration except for zinc-sulphate and NPKS, which respectively drew 33.3 and 50 per cent adulteration. The samples were supplied by the DAE, fertiliser importers and dealers, and law enforcing agencies.
The same year, it tested 533 samples of fertiliser, supplied by the farmers and analysed in its regional laboratories in Dhaka, Comilla, Rajshahi and Khulna, and found six per cent of these 'fake' and 30 per cent sub-standard.
It was found in the tests that the borax contained only 5 to 6 per cent boron against the required level of 17 per cent while 2 to 12 per cent zinc in zinc-sulphate against 21 to 36 per cent required. They also found mixture of ash and brick-powder with TSP and MOP as alternative to phosphate and potash. According to the fertiliser control ordinance, every fertiliser factory must have a quality testing laboratory, but most of the factories do not have any such lab. Acknowledging absence of the labs in fertiliser factories, a top DAE official said, 'There are about 70 approved factories in the country, but we are not sure how many factories are running without the labs.'
He, however, said they would immediately find out such factories and go for action. Citing fund crunch as an impediment, he said as we cannot test the standard of fertiliser as and when required due to the fund crisis, it ultimately hampers the overall monitoring process.
As the fertiliser are produced and sold in every corners of the country, action against adulteration and production of low-quality fertiliser could not be taken without promptness of the root-level monitoring committees,' he said. The Bangladesh Fertiliser Association executive secretary, Reaz Ahmed, said the government monitors the quality of imported fertiliser before entering into the country, but 'practically' there is no monitoring for the locally produced fertiliser and the marketed fertiliser, both local and imported. The annual demand of fertiliser in the country is 42.5 lakh tonnes.
Although there are about 70 fertiliser factories in the country as per the government statistic, the actual number is many more, they said and referred to the unearthing of a few number of fake factories in the last couple of years. Unconfirmed sources said there are over 100 'fake' fertiliser factories in the country, mainly in the south-eastern districts (O. Ghani, New Age, August 2, 2005).Fake Fertiliser
Fertiliser plant rains toxin on people
large amount of toxic ammonia, highly soluble in water and released from the country's largest urea producing Jamuna Fertiliser Factory (JFF) at Tarakandi under Sharishabari upazila of Jamalpur district, has been wreaking havoc on the local environment causing debilitating illnesses among the residents of the area for the last 16 years. The gas emitted by JFF has also been destroying the crops, livestock, poultry, and fishes of the area worth crores of taka every year. The factory produces 1,700 tons of urea a day, for which it also produces ammonia as an input.Top of page
Factory sources said since the beginning of operation they have been producing an extra 300 tons of ammonia than required everyday, and that superfluous amount of toxic gas has been being released into the environment through the plant's exhaust system on a daily basis since 1991, when the factory started its operation. The factory authorities did nothing to stop the environmental disaster despite continued protests from thousands of affected local people over the years. Crops, trees, poultry, livestock, and fishes in adjacent Kandarpara, Tarakandi, Charpara, and Dhuriarbhita villages have been dying due to the emission of the toxic gas from the factory. Croplands of the area have become arid due to the pollution of many years.
This correspondent recently visited Kandarpara village. As he entered the affected area, a heavy acrid smell of ammonia hit his nostrils making it very difficult to breathe and very soon his eyes also started to burn, making the visit quite injurious to personal health. But the villagers have been living in this dangerous situation for 16 years now. Trees of the village have already died while the water of the ponds have become poisoned and discoloured.
Azizul Haque, 50, of Kandarpara said he had cultivated different kinds of fishes in his three ponds last year with loans from the local Krishi Bank, but the fishes worth about Tk 1 lakh died due to the ammonia mixed in the pond water. "I went to the factory authorities including the managing director with the dead fishes in my hands but they paid no attention to my complaint and did nothing about the problem," he said. The farmers of the worst affected four villages are feeling helpless as yields of their boro crop on 200 acres of land contained no grain in them last season due to the effect of the large amount of ammonia in the environment, local residents said.
Razzak Ali, a landless farmer of Kandarpara village said during the last boro season he had cultivated boro rice on 35 bighas of land taking advance payment from buyers, but his entire yield of the crop turned out to be sterile. "I invested Tk 36,000 for the cultivation but the entire yield of paddy was sterile due to the ammonia in the environment," he said adding, "Now I don't know how I'm going to repay." Not only Razzak, most of the farmers of the village including Tota Miah, Joinul Abedin, Shamsher Ali, Khanu Miah, Badal Miah, Abdul Aziz, Marfat Ali and Suruj Ali are also suffering from similar fates.
The hepless population who grow food items that probably end up on the dinner tables of many powerful people in the capital, have been left to suffer for the last 16 years while the local environment was being permeated by toxic ammonia emitted from the government run fertiliser factory infecting the population with diseases like asthma, bronchitis, blindness and different kinds of skin diseases. Rina Begum, a housewife living in Kandarpara village, said her three minor children have been constantly suffering from diseases over the years.
Marfat Ali of the same village said three of his six brothers and their families already left the village due to the pollution. "I will also leave the village as soon as possible with my wife and children," he said.
Shamsher Ali of the village said, "I am only 40 but I can't see clearly anymore, moreover my hair has already fallen due to the pollution." The local residents alleged that they held protest programmes like forming human chains, blockading the factory gate, submitting memorandums to the JFF authorities, etc, but the authorities seemed to keep getting away with not caring at all with impunity years after years.
The villagers repeatedly demanded that the authorities concerned build a waste treatment plant on the factory premises to stop the pollution of the environment and to put an end to the wanton destruction of their lives, but that seemed to fall on deaf ears only (Mirza Shakil, Daily Star, July 8. 2007).
Government recommends dangerous banned pesticides
CHAPAI-NAWABGANJ, Mar. 6:–The scientists of the Regional Horticulture Research Station (RHRS) under Bangladesh Agriculture Research Institute (BARI), Chapai-Nawabganj, widely known as the Mango Research Station, are providing conflicting information to the people about their research works and achievements. They are also distributing book-lets prescribing banned pesticides to control pest-attacks on mango. In the same book-let the above sceintists have prescribed some banned pesticides including Roxin, Rogor, Bidrin, Azodin, Monodrin, Bidrin and Poligor to control the attack of Apsyllla, a kind of dangerous pest of mango. Now the question arises how far justifiable it is for the scientists to spend the public money for publishing a book-let to give confusing information to the people as well as to tell them to use banned pesticides (Bangladesh Observer, March 7, 2005)..
Ban toxic pesticides, demands rally Chemical pesticides kill 2,20,000 a year worldwide: Chapai Nawabganj, December 6, 2003:
Farmers joined by cross-sections of people marched the streets of Chapainawabganj town and held a rally protesting use of chemical pesticide and fetiliser in agriculture.At least 20,000 people die in the world due to poisonous effects of chemical pesticides and about two lakh commit suicide by taking those in a year, the rally was told quoting WHO statistics.
At least 20,000 people die in the world due to poisonous effects of chemical pesticides and about two lakh commit suicide by taking those in a year, the rally was told quoting WHO statistics. Several hundred processionists including teachers, lawyers, and students carrying banners and festoons marched the streets chanting various slogans.
The programme was organised by the local unit of UBINIG in observance of the 'International No Pesticide Use Day' on Wednesday.
Quoting from a WHO report, Shamsul Haque said four pesticides among the 'Dirty Dozen', banned in other countries, are "widely used in Bangladesh through the Department of Agriculture Extension". These do not really increase agricultural output but destroy soil fertility, environment and bio-diversity. Fish resources have depleted mainly due to their use. Many farmers in Bangladesh have now realised this and are using organic fertiliser like cow dung and compost fertiliser and are getting better results, he said.
Pesticides produced from leaves of different plants and trees including 'Neem' are now being used in many countries now, he said. But the government is giving little attention to popularise organic fertiliser and gradually reduce use of chemical pesticide and chemical fertiliser, he alleged. He mentioned that highly poisonous pesticides which are very destructive for land and bio-diversity are being smuggled freely from across the border. Other speakers called for building up a movement to popularise use of organic fertiliser and to ban pesticide.Neem - The Wonder plant
Toxic insecticides destroying food chainBangladesh Paribesh Andolon (BAPA), an environmentalist group, yesterday demanded enactment of stricter laws for effective control on the use of insecticides in agriculture and to stop import and use of toxic chemical substances. The BAPA made the demand at a citizens’ rally held at Shahbag in the city. BAPA also demanded proper training to the sellers and users of insecticides to ensure a safe and secure environment. They also called for introducing new and alternative methods of pest and disease control.
The green activists also formed a human chain in the area. They stressed the need for increasing awareness among the farmers, traders and consumers about the harmful effects of toxic chemical insecticides on the food chain and human health. They urged the government and the civil society to make a concerted effort for enacting stricter laws to stop use of toxic insecticides in agriculture. The speakers called upon the conscious citizens to launch a vigorous campaign to stop wanton use of insecticides in agriculture that is damaging the environment.
The speakers at the rally said that despite a government ban on sales of toxic insecticides the chemical substances were being sold to farmers who were using those in agriculture, especially in production of vegetables without being aware of their harmful effect. Shishuk, Biswa Shahitya Kendra, Sheba, Hunger Free World, Institute of Environment and Development (IED), Usha, Peace, Battikrom Manab Kalyan Sangstha, Green Force and World Peace Organisation expressed solidarity with the campaign of BAPA (The Independent, December 9, 2003)-Top of page
Arsenic contaminates millions of people's drinking water in West Bengal and Bangladesh, but scientists now think they might have figured out how the toxic element gets into the water in the first place. The discovery could help authorities to decide where to site new wells and stop this problem escalating
For more than twenty years, people in West Bengal and Bangladesh have been drinking water from tube wells that tap into groundwater, rather than using untreated surface water. While this has helped reduce gastrointestinal diseases, it has inadvertently led to the one of the most serious water quality problems in history. More than twenty million people are now drinking water contaminated with arsenic, with tens of thousands already diagnosed with arsenic poisoning. Scientists think that arsenic in the groundwater comes from sediments washed down from the Himalayas. Oxidised iron in the sediment traps arsenic, also present in an oxidised form known as As(V). Over time, the sediment becomes buried and covered with water. But as bacteria break down organic carbon compounds in the sediment, the iron oxides are reduced to a lower oxidation state, breaking their bond with arsenic and releasing it into the groundwater.
Andy Meharg of Aberdeen University, UK, and colleagues have now analysed levels of arsenic, iron and organic carbon in a range of affected sediment, and say that they can identify the type of river sediments that pose the highest risks
Since organic carbon ultimately sets the release of arsenic in motion, finding its source is crucial, says team member David Kinniburgh of the British Geological Survey in Wallingford. 'We showed for the first time that there is a definite positive correlation between arsenic and organic carbon, which is not what would necessarily have been expected,' he says. This implies that arsenic and carbon are buried at the same time in the sediment, the team argues in Environmental Science and Technology.1
Meharg's team believes that the carbon involved comes from vegetation, such as mangrove swamps. They did not find any evidence, says Kinniburgh, to support alternative theories that organic carbon is derived from buried peat, or from surface pollution, such as latrines.
If they're right, then the work will have dramatic implications, says Charles Harvey, a geochemist at Massachusetts Institute of Technology, Cambridge, US. Yet he remains sceptical: 'The paper does not show a relation between the sediment characteristics and arsenic in the groundwater,' he says. 'There may be a strong correlation between solid arsenic and solid organic carbon - but what is the relation to dissolved arsenic?' he asks. Harvey points out that rich deposits of solid arsenic do not necessarily go hand in hand with dissolved arsenic. 'Perhaps dissolved arsenic is low in locations where the solid arsenic is high, because the solid arsenic is not dissolving there,' he suggests. 'We just don't know.' Zafar Adeel, an expert on Bangladesh's water crisis at the UN University in Hamilton, Canada, is also cautious. 'They argue that if arsenic concentrations follow the organic carbon profile then it would be better to have deep aquifers where organic carbon levels are very low,' he says. 'But I would be concerned if people switched from shallow to deep aquifers without further investigation.'
'Microbes to blame' for arsenic threat to millions
Researchers claim to have identified the process responsible for contaminating groundwater with arsenic, a phenomenon that endangers the health of tens of millions of people, mostly in Bangladesh and India.
The scientists describe their research as a breakthrough, and say that it can help identify areas at risk, and could eventually lead to ways of cleaning up contaminated water.
According to the research published today in Nature, bacteria are responsible for the release of arsenic into water from surrounding earth. The microbes gain energy by changing the chemistry of minerals containing both iron and arsenic, and release the arsenic into the water as a by-product of the reaction. Without such bacterial activity, the arsenic would remain in an insoluble form, and thus be unable to contaminate the water. "This research means we now have a much better idea of how arsenic is released into drinking water and aquifers in the region," says Farhana Islam, a Bangladeshi PhD student at the University of Manchester, and lead author of the study. "The results will help to inform ways of [detoxifying] the water, leading to a healthier supply for thousands of people."
The researchers collected earth samples at a depth of 13 metres from a site in West Bengal known to have relatively high concentrations of arsenic in the water. The samples were mixed with groundwater in a laboratory and exposed to a range of biological, geological and chemical factors. The scientists found that arsenic was only released from the earth samples in the absence of oxygen, and that the presence of organic matter — derived from decaying animal and plant life — enhanced this process. This is because the bacteria's ability to gain energy from surrounding minerals is influenced by the quantity of carbon (which all organic matter contains) present.
This conclusion reinforces speculation that human activities that increase the amount of organic matter underground — such as irrigation pumping, during which water drawn from below ground is replaced by water containing organic matter seeping down from above — may promote the release of arsenic into groundwater (Agricultural pumping linked to arsenic).
According to the researchers, the suggested link between iron and arsenic would mean that some of the processes at work could be reversed. For example, one way of treating contaminated water could be to add air to it for a suitable period of time prior to drinking. This could reverse the release of arsenic and reform an insoluble mineral that could be removed by a simple filter (Reference: Nature 430, 68 (2004).)
In a related paper,2 Meharg has found that many Bangladeshis are also consuming arsenic when they eat rice. In southwestern Bangladesh, rice that had been irrigated with contaminated groundwater contains enough arsenic to pose serious health risks, they found in a survey. The team suggests that in areas with high concentrations of groundwater arsenic, farmers should be encouraged to use surface waters for irrigating rice, or to substitute rice for cereal crops that require less irrigation (Maria Burke, Chemistry World, 2006).
Modern Agriculture and the Ecologically Handicapped Fading Glory of Boro Paddy Cultivation
This study attempts inter alia to understand the rationale of farmers' choice of boro paddy harvest in a situation of declining profitability and growth in output, the impact on groundwater reserves in West Bengal and damage to the soil substrate caused by such monocropping. Despite a dearth of scientific data on the polluting effects of agrochemical dumping, indicators show that a large number of farmers of West Bengal who are growing boro paddy are becoming ecologically handicapped. SREERUPA RAY, DHRUBAJYOTI GHOSH (Economic and Political Weekly June 30, 2007 2534).
Arsenic contamination has also been reported in the food chain in rice irrigated with arsenic contaminated groundwater [Chakraborty et al 2001]. About 140 lakh of people in 75 blocks of eight districts of the state suffer from arsenic poisoning in their drinking water. It is needless to mention that these areas with huge tracts of land under boro paddy cultivation, absolute reliance on groundwater, low possibility of adequate replenishment of the groundwater reserve from rainfall, lack of necessary surface water irrigation are tending towards an unsustainable future.
The green revolution provided food security that the farmers dreamed about for so long. However, after two decades, today it will be difficult to meet many farmers in West Bengal/Bangladesh who are happy to cultivate the crop. The economic return from the crop is negligible; at the end of the season the farmers hardly have a surplus to sell in the market. But the data reveal an ever-increasing trend in the area under boro paddy. The farmers do not have a better alternative for their already degrading land. It is not only the land but also water underneath, crops and health of the farmers that are being seriously damaged. Beyond economic hardship, farmers are ecologically handicapped and this exhausts their ability to make any profit. The productivity-driven prosperity of the 1980s could not be sustained in the long run, in fact it has now become a cause for concern for farmers.
Irrigation has been an important factor for cultivating high yielding varieties of crops. In West Bengal, the area under cultivation of irrigated HYV rice increased rapidly from its initiation.
Damage to Soil Substrate and Rising Pollution
The soil condition required to cultivate transplanted paddy is distinctly different from other crops. Wetland or submerged soil condition having poor internal drainage capacity is a pre-requisite for transplanted paddy. This distinguishes the soil chemistry of wetland paddy from other upland crops. Paddy by nature prefers to keep its root system in a reduced layer, oversaturated by water and almost devoid of oxygen. This is in contrast to the soil's natural environment of well-drained to moderately well-drained conditions with a reasonable supply of air and water - an environment that is preferred by majority of crops and huge symbiotic aerobic microbial population. The typical wetland-chemical condition of the soil favourable for transplanted paddy needs to be created, that is, a poorly drained condition with soil reduction phase, irrespective of soils natural drainage properties.
This typical process has turned vast tracts of moderately well-drained irrigated land to imperfectly drained to poorly drained. The traditional crop sequence that farmers used to follow, i e, either keeping the land fallow during the winter and summer months or cultivating crops other than wetland paddy in between, naturally restored the soil from the temporary poorly drained status.
. The degradation or pollution of the soil's natural environment for diversified crop-growth has been further aggravated by the uncontrolled use of chemical fertilisers and plant protection chemicals by farmers. For rice in general, fertiliser consumption has increased over time with the irrigated variety consuming more than the unirrigated one.
The efforts of farmers to increase the yield of boro paddy, though abortive have resulted in the uncontrolled use of groundwater and agrochemicals. The water and soil substrate have, in many cases, become a matter of serious environmental concern because of the change in the traditional cropping pattern that altered the natural properties of a stable and friendly agroecosystem. Today agrarian life in the state has become difficult.Farmers are comprehensively challenged. Modern agriculture has consistently encouraged a cropping practice that is exploitative of land and people. It has systematically undercut all other agrarian values. Nevertheless, the system with all these visible signs of unsustainability is still flourishing. What is more surprising is that the consequences do not influence the farmers' decision to cultivate the crop.
Farmers are aware of the inadequacies of modern agriculture but they cultivate the crop out of compliance. What farmers need is a tangible alternative, a choice that values water as a precious resource and recognises the ecological margin of the use of land. A business-as-usual approach will lead to the permanent destruction of our agrarian ecosystems. Contract farming is waiting to come. If it does so on the basis of any imprudent terms, it may further destabilise the traditional knowledge base of our farmers, which grew for hundreds of years and whose relevance has been far from being obsolete.
Arsenic-contaminated irrigation water produces toxic crops
Crops produced by arsenic-contaminated irrigation water accumulate toxic element, and when these contaminated foods are taken, human body becomes sick, said a study yesterday. The study titled 'Arsenic poisoning in the food chain and its remedial possibilities' was presented as second dean lecture by Prof S M Imamul Haq of Dhaka University at the Teachers Students Centre auditorium. The study also showed that rice and other food grains like arum, green papaya, bean, potato, bitter gourd, aubergine and chilli cooked in contaminated water also contain substantial amount of arsenic.Top of page
Prof Imamul said around 19 percent of the total population consume excessively arsenic-contaminated rice. Terming this an urgent matter, the study said only safe water can reduce the risk of arsenic contamination.
He also showed some findings to reduce the contamination. "It has been observed that mixing surface water with ground water could reduce the arsenic contamination by about 50 percent," said Prof Imamul, adding that organic and inorganic substances including cow dung, poultry feces, litters, sewage and composts could reduce the accumulation of arsenic in soil.
The study also showed two indigenous ferns, pteris vittata and nephrodium molle, could remove arsenic from soil. Arsenic is a major concern of the world as the ground water in 20 countries is contaminated, and in Bangladesh more than 80 percent ground water is contaminated by arsenic.
The chief guest at the lecture series Prof Nazrul Islam, chairman of the University Grants Commission, said although research is a mandatory part of university education, the teachers at present are not interested in it. Admitting the fund constraint for research he said the government has allocated Tk 10 crore for research purpose which will help reduce the crisis.
He also noted that the University Grants Commission is going to sign a deal with the World Bank for funding research projects. "After the sighing of the deal with the World Bank, the fund crisis will be solved," the UGC chairman added. Presided over by DU Vice-chancellor Prof SMA Faiz, the lecture was also attended by Prof Anwar Hossain, dean of Biological Science faculty, and Prof Harun-Or-Rashid, dean of Social Science faculty (DU Correspond, August 3, 2007).
Researchers have pinpointed the source of what is probably the worst mass poisoning in history, according to a study published Sunday. For nearly three decades scientists have struggled to figure out exactly how arsenic was getting into the drinking water of millions of people in rural Bangladesh.
The culprit, says the new study, are tens of thousands of man-made ponds excavated to provide soil for flood protection. An estimated two million people in Bangladesh suffer from arsenic poisoning, and health experts suspect the toxic, metal-like element has caused - and will continue to cause - many deaths as well.
Symptoms include violent stomach pains and vomiting, diarrhoea, convulsions and cramps. A large dose can kill outright, while chronic ingestion of small doses has been linked to a large range of cancers. It has long been known that the arsenic comes from water drawn from millions of low-tech 'tube wells' scattered across the country. Ironically the wells were dug - often with the help of international aid agencies - to protect villages from unclean and disease-ridden surface water.
Tragically, millions of people continue to knowingly poison themselves for lack of an alternative source of water. Earlier studies succeeded in filling in a few pieces of the deadly puzzle.
They showed that water with the highest concentrations of arsenic is roughly 50 years old, and that the organic carbon which, once metabolised by microbes causes the poison to leach from sediment, does not take long to filter down from the surface. But the source of both the contaminated water and the organic carbon remained unknown until a team of researchers led by Charles Harvey of MIT in Boston, Massachusetts cracked the secret.
Working in the Munshiganj, the researchers analysed the flow patterns of surface and underground water in a six square-mile area.
They used natural tracers and a 3-D computer model to track water from rice fields and ponds, and tested the capacity of organic carbon in both settings to free up arsenic from soil and sediments. 'We saw that water with high arsenic content originates from the human-built ponds, and water with lower arsenic content originates from the rice fields,' said Rebecca Neumann, a co-author and postdoctoral associate at Harvard.
Chemical analysis showed that the organic compound that unleashes the poison first settles on the bottom of the ponds and then slowly seeps into the ground. The findings, published in Nature Geoscience, 'suggest that the problem could be alleviated by digging deeper drinking water wells below the influence of the ponds, or by locating shallow drinking wells under rice fields,' Neumann said in a communique.
The same team of researchers plan to dig such wells in different region to see whether it leads to improved health for villages.
Scott Fendorf, a professor at Stanford University who studies arsenic content in soils and sediments along the Mekong River in Cambodia, said the new study was clearly a breakthrough. 'It shows that human modifications are impacting the arsenic content in the groundwater,' he said in a statement. 'The ponds ... are having a negative impact on the release of arsenic.'
The origin of dissolved arsenic in the Ganges Delta has puzzled researchers ever since the report of widespread arsenic poisoning two decades ago. Today, microbially mediated oxidation of organic carbon is thought to drive the geochemical transformations that release arsenic from sediments, but the source of the organic carbon that fuels these processes remains controversial. At a typical site in Bangladesh, where groundwater-irrigated rice fields and constructed ponds are the main sources of groundwater recharge, we combine hydrologic and biogeochemical analyses to trace the origin of contaminated groundwater. Incubation experiments indicate that recharge from ponds contains biologically degradable organic carbon, whereas recharge from rice fields contains mainly recalcitrant organic carbon.
Despite the complexity of these processes, our results have several implications for safe drinking water.
Throughout Bangladesh, and in some other regions where arsenic contamination is likely,our research suggests that the development of artificial ponds above wells should be avoided if it is possible, and that drinking-water wells should not be placed downstream of recharge from existing ponds, wetlands, rivers or other permanently saturated water bodies potentially elevated in organic carbon.
Our results also suggest that shallow wells beneath rice fields could offer a source of safe groundwater, particularly if accumulated arsenic in the rice field is removed annually during flooding (L. Roberts et al., unpublished).
Chemical and isotopic indicators as well as groundwater simulations suggest that recharge from ponds carries this degradable organic carbon into the shallow aquifer, and that groundwater flow, drawn by irrigation pumping, transports pond water to the depth where dissolved arsenic concentrations are greatest. Results also indicate that arsenic concentrations are low in groundwater originating from rice fields. Furthermore, solute composition in arsenic-contaminated water is consistent with that predicted using geochemical models of pond-water–aquifer-sediment interactions. We therefore suggest that the construction of ponds has influenced aquifer biogeochemistry, and that patterns of arsenic contamination in the shallow aquifer result from variations in the source of water, and the complex three-dimensional patterns of groundwater flow( Rebecca B. Neumann1, Khandaker N. Ashfaque1, A. B. M. Badruzzaman, M. Ashraf Ali, Julie K. Shoemaker & Charles F. Harvey Nature, 15 November 2009,).
Our Results- Wells near Ponds
Our results show that many wells close to ponds found to be arsenic free. For example visit Kabi Jasim Uddin House at village Ambikapur, Faridpur the well close to pond is arsenic free, whereas wells at rice field are arsenic contaminated.
The distribution of vertical flows is highly dependent on the assumed lithological profile. Lithology therefore has to known in detail. This is especially important for considering flow to the deep aquifer. Lithological information from the borehole log obtained for Faridpur suggests that there is not an extensive, well-defined aquitard layer (which is found in southern Bangladesh, a thick layer of clay sediments in many places) between the shallow and deep aquifer. In other words, contaminated shallow aquifer can flow to deep aquifer.
The stratigraphy of the Upper Ganges-Brahmaputra delta shows different patterns and controls than those in southern Bangladesh (coast). Sandy channel deposits comprise nearly the entire subsurface stratigraphy across a broad area from Hooghly River distributaries to the main channel of the modern Ganges-Brahmaputra River. Boreholes from this area reveal little or no subsurface floodplain deposits (Goobred, et al., 2003). This situation suggests that floodplain deposits are wholly removed over longer terms (103 years) in this part of the basin, despite rapid aggradation during the early Holocene. The seasonal discharge and large sediment load (esp. bed load) of these rivers favour channel migration and avulsion, and thus the lateral erosion of interchannel floodplain units (Hannan, 1993).
Since the donors/government policy to make deep tube wells in every villages of Bangladesh, expensive deep tube wells are set without considering lithology, lateral and vertical flows.
The principal goal of this project is to introduce least cost-effective, efficient and appropriate method to obtain arsenic free water in the light of adaptability, social acceptance, sustainability and easy reproducibility within Bangladesh environment. We are pleased to see that many afforable persons in rural areas followed our principles and hired our trained personals, in other words, additionally thousands of people has been benefited. A project can not be succesful without the traditional, social, cultural heritage of the rural poor population of Bangladesh.
Accessing the risk of arsenic ingestion with mineralogy
Mineralogy, percent arsenic bioaccessibility and total arsenic concentration of samples from Nova Scotia mine tailings. Detailed mineralogical analyses of individual samples revealed up to seven arsenic species in individual samples (six shown here as major arsenic phases). Results of a physiologically based extraction test are for the < 150 µm particle size fraction. A weak correlation is observed between total and bioaccessible arsenic concentrations. The percent arsenic bioaccessibility is most influenced by the presence of a more soluble arsenic species, even in low concentrations. Lower percent bioaccessibility in the majority of samples is associated with sparingly soluble arsenopyrite and scorodite.
Higher percent bioaccessibility in some samples is attributed to the presence of calcium-iron arsenates and arsenic-bearing iron oxides. The star denotes the presence of a minor calcium-iron arsenate phase.
Canadian researchers working at Brookhaven's National Synchrotron Light Source (NSLS) have created a method for determining how much of the arsenic in soil tailings -- byproducts of the mining industry -- will enter the bloodstream if ingested. (September 10, 2010 By Sophi Bushwick Enlarge)
"People tend to get frightened when they hear about chemicals in the environment, but those chemicals have to get in the bloodstream first," explained lead researcher Kenneth Reimer, director of the Environmental Sciences Group at the Royal Military College of Canada. "The default assumption is that all arsenic attached to ingested particles will enter your system, but you're going to eliminate some of it through waste."
Those who live near past and present mining sites may accidentally consume soil samples containing arsenic. (In fact, children eat an average of 80 milligrams of dirt a day, four times as much as adults.) In order to ensure that harmful mining waste is properly dealt with, it is important to determine how much of an ingested chemical is absorbed by the body rather than passed harmlessly through the digestive system. Scientists can approximate this as the chemical's bioaccessibility.
"Bioaccessibility gives us a much better idea of the actual risk involved in arsenic ingestion," explained Reimer. "It's much more accurate than just using the default assumption of 100 percent absorption."
Bioaccessibility testing approximates the percentage of an ingested chemical that will enter the body, without requiring animal or human testing. Instead of feeding samples to a test subject, a bioaccessibility test runs the sample through conditions that simulate a digestive system, complete with mock gastrointestinal fluids. The percentage of arsenic that dissolves during this process reveals the sample's bioaccessibility.
But what if, instead of running these tests on numerous soil samples from throughout a mining site, researchers could describe the relationship between a sample's bioaccessibility and the specific minerals in it — its mineralogy? Reimer and his team sought to do so, examining the bioaccessibility and mineralogy of soil samples taken in the gold mine districts of Nova Scotia, Canada
Arsenic in Crop
Unabated mining of groundwater for irrigation is causing heavy deposits of arsenic in vast tracts of the country's cultivable lands, posing a threat to crop production in future. Noting that non-flooded lands are particularly at risk of arsenic accumulation due to heavy dependency on groundwater irrigation for paddy production, two Bangladeshi researchers have cautioned against further expansion of dry-season rice -- Boro-- at the cost of depositing more arsenic in soil.
They also found penetration of arsenic into the grains, though at a low level. And they found presence of up to 0.3 milligram of arsenic in per kilogram of paddy grown in their research site in Munshiganj district. Prof M Ashraf Ali, one of the researchers, said, "We cannot say for sure the degree of health hazard it poses for human body right at the moment as there is no set standard of permissible arsenic level in food as yet."
He went on, "If the croplands continue to accumulate larger amount of arsenic, the level of its penetration into the food chain will be higher too posing greater risks." Arsenic is a notoriously poisonous metalloid classified as a Class-1 carcinogen, meaning it is too harmful to humans. Other Class-1 carcinogens include asbestos, formaldehyde and hepatitis B and C viruses.
A galaxy of leading arsenic researchers from home and abroad studied the impact of irrigation with their findings published in the January issue of the London-based Nature Geoscience. The researchers include ABM Badruzzaman and M Ashraf Ali, both professor of civil engineering at Bangladesh University of Engineering and Technology.
Talking to The Daily Star at Buet recently, the two experts said arsenic drawn to the surface by groundwater irrigation is largely removed (up to 62 per cent) in the following monsoon if the lands go under floodwater about one metre in depth. But paddy fields not experiencing typical monsoon flooding are particularly at risk of arsenic accumulation, posing a potential threat of penetrating into food chain in future, they said.
According to official statistics, only 21 percent of Bangladesh's total lands are submerged by floodwater around a metre in depth while the rest remains largely vulnerable to arsenic accumulation due to mining of groundwater. Badruzzaman and Ashraf Ali, having long track records of arsenic research, worked for years along with co-researchers at an experimental site in Mnshiganj. The team included experts from from Massachusetts Institute of Technology and Harvard University, USA, and a couple of Swiss and German research centres of excellence. The current issue of Nature Geoscience that has an editorial titled 'Digging Deeper'focused on arsenic issues and carried their findings based on field studies.
The researchers said up to 250 milligram (mg) of soil arsenic (in per square metre of cultivable land) is released into floodwater during the monsoon season, which correspondents to a loss of up to 62 percent of the arsenic added to soil through irrigation each year. The rest is deposited in the cropland unless removed by 'volatilisation and transportation' to deeper layers. Their field studies found large tracts of paddy lands that do not experience yearly monsoon flooding continue to be burdened with accumulated deposits of arsenic drawn to the cropland through irrigation.
Bangladesh's food basket now heavily depends on the irrigated-rice Boro that contributes 60 percent of annual rice output, far surpassing the rain-fed Aman output. Explaining the reasons behind arsenic accumulation due to groundwater irrigation, Badruzzaman said, "Due to drawing of groundwater by over a million shallow pumps from 100-150 feet beneath the surface, 'young' water gathers from all possible directions and with that 'young' carbons get oxidised dissolving iron and mixing arsenic into the water."
Cultivable lands, annually washed by monsoon floods, said Badruzzaman, are relatively safer in terms of arsenic accumulation but "policy planners need to seriously think over extracting groundwater for irrigation in non-flooded lands." Ashraf Ali emphasised further studies on arsenic and irrigation issues so that various mitigation and adaptation mechanisms can be developed.
Both of them also stressed efficient use of water by Bangladeshi farmers in growing winter rice. Over half of the country's 8.4 million hectares of arable land are under irrigation now. And typically the rice growers use 3,000 litres of water to produce one kilogram of dry-season rice. (Daily Star, January 15, 2010).
Arsenic found in infant
Environmental chemist Andrew Meharg of Aberdeen University in Scotland and colleagues tested 17 samples of baby rice from three British supermarkets, The Daily Telegraph reported Wednesday. He said high levels of arsenic were also found in rice products such as rice milk and puffed rice cereal. "I don't want to give out nutritional advice to the public, but as a parent I would try to reduce my baby's exposure to any contamination," he said.
A Food Standard Agency spokesperson said surveys show arsenic levels in infant foods are "as low as reasonably practicable" but said the agency would continue to monitor the situation.
The newspaper said the current standard for arsenic was set in 1959 before arsenic was recognized as a carcinogen. (May 1, 2008)
1.Arsenic and Uranium in Fertilizer
2. Radioactive Mineral in Drinking Water of Bangladesh
3. Green Revolution
4.Argument against Natural Origin
5. AGROCHEMICALS : IMPORTED POLLUTANTS IN BANGLADESH
6. Arsenic poisoning: man-made disaster
7. Dams/Barrages Relation to Recent Arsenic Poisoning
7. Rice - IRRI High Yield Producing Countries in River Plain faceing Arsenic Contamination
8.ARSENIC AND OTHER TOXIC METALS IN BANGLADESH’S DRINKING WATER
9. Is groundwater arsenic poisoning in Bangladesh a natural or a man made disaster?
Last Modified: October 23, 2010