AGROCHEMICALS : IMPORTED POLLUTANTS IN BANGLADESH
Since 1986 there is a rapid increasing of fish diseases, and it can be correlated with the increase use of agrochemicals, disposal of untreated industrial and municipal wastes etc. to river waters, and low-lying water reservoirs. Research studies in industrial countries have shown that mainly chemical contamination effects the habitat in aquatic environments. In Bangladesh there is a rapid increase in the use of pesticides and chemical fertilisers for the growth of newly introduced HYV crops. Some extremely hazardous pesticides (the dirty dozen) are used in the country. Pesticides and other contaminated water enter the low-lying beels, haros and rivers. Around 270 species of bird and 120 species of commercially important fish are exposed to danger. The "green and genetic revolution" which was to feed the world hungry is destroying the genetic base of the food supply. There were about 30,000 rice varieties cultivated by the farmers in the Indian sub-continent but at present only 15 varieties. The new HYV's are unstable to environment, replacing the environmentally sustainable plants that were preserved by our ancestors since thousands of years. Bangladesh should encourage to improve farming techniques for traditional varieties under regulated flash of nutrient rich flood water, reducing reliance on chemicals, improvement of quality of health aspects of food production, protecting water supply and creating an environment more congenial for human and habitat.
In Bangladesh fish is the most vital supplier of animal proteins and about eight per cent of the population and 1.2 million professional fishermen earn their livelihood from fishing, which ranges to about eight million metric tonnes annually. Inland water fisheries account for more than 70 per cent of the total fish catch but the price hike and non-availability of many varieties of fish types indicate a decline of inland fisheries.
It is presumed that over fishing, structural measures to prevent river overflows and an increasing use of low-lift pumps result in a loss of habitat as floodplains are drained. On the other hand, there is a gradual growth in water pollution by increasing use of agrochemical, uncontrolled disposal by industrial, municipal and urban wastes to river waters that not only deplete available oxygen supply but also dispose viral infections, extinction of aquatic habitats and increasing long term health hazards.
Recently the main varieties of eatable fish in lakes, beels, haros (flood-plain depressions), baors (ox-bow lakes) contain parasites associated with black spot in bass or with external growths, tumours or other lesions, lip and skin growths. Such tumours and abnormal growths are locally known as "fish-pox", and the poor fishermen and villagers do not know the background of such disease and the government and other institutions have not adopted any project or taken any necessary action (Nahar, 1992). However, a team of experts from the University of Stirling, UK, visited several effected areas in Bangladesh, but they could not identify any environmental parameter contributing to this disease (Ali,1994). Ahsan (1990) reported the occurrence of fish epidemics in different parts of the country and it is apprehended by the scientists and local people that fish moralities in the open water of Bangladesh have occurred due to uncontrolled use of pesticides. Pesticides like Aldrin, dialdrin, Endrin and Heptachlor are extensively used in Bangladesh. Dialdrin is about 40 to 50 times more toxic than DDT (ESCAP/UN, 1988). A few drops of Aldrin or Endrin can kill all the fish in pond and these compounds persist in the soils for a long period (Ali, 1994). Most species of fin-fish cannot survive insecticide in concentrations greater than 1 to 10 ppb (parts per billion). An abnormal reduction of shrimp fry in natural water have occurred in Bangladesh - natural sources could met only 10 per cent of the total demand (Nandy, 1996).
Since 1986 there is a rapid increase in such diseases which can be correlated to the increasing use of agrochemical and the discharge of untreated industrial and municipal wastes to river waters. Besides, a new disease known as Epizootic Disease is causing fish mortality in open and closed waters in an epidemic form. The disease affects almost all popular eatable fishes (local names) such as Taki, Shol, Baim, Kholisha, meni, Punti, Bele, Rui, Catla, Mrigal and their juveniles, however the disease causing factors could yet be diagnosed (Ali, 1992). The physical characters and other environmental conditions of the water body are important factors that determine the levels of residue contamination in the fish. Freshwater fish, in general, have higher residue burden than marine fish (Brevik, 1981).
During the past decade toxicological research has indicated that the immune system, on which defence mechanisms depend, is a potential target for many chemicals foreign to the body. Experimental studies show that toxicological effects of chemicals on the immune system produce changes in the weight and microscopic appearance of lymphoid organs, altered numbers of blood leukocytes, and in the impairment of immune cell functions. Such toxicity may result in an increased incidence of infectious diseases or in the development of certain tumours ( Vos et al., 1987 ).
Several instances of mass mortality of fish have been reported immediately following the massive application of pesticides. In 1950, simultaneous occurrence of fishkills in 15 tributaries of the Tennessee river in Albama, USA reported. These fishkills were associated with rainfall runoff from agricultural fields, following the application of chlorinated hydrocarbon insecticides (Nicholson, 1967). According to Holden (1964), many of the reported cases of mass mortality in Great Britain were attributed to accidental spillage of agricultural chemicals. The discharge of about 90.700 kg of chlordecone into the James river estuary during the manufacture of this compound at Hopewell Va., USA, between 1966 and 1975, led to closure of commercial and sport fishing in the estuary ( (Lunsford, 1981). Since the last decade research studies on tumours or infectious diseases in fish in industrial countries have been conducted (Sindermann, 1983; Mailns et al., 1988 and Overstreet, 1988). Results show that mainly chemical contamination effects the habitat in aquatic environment. Pollutants, once they have entered living organisms, find themselves in contact with enzyme systems that can make them metabolic alternations. These alternations, which use a series of biochemical processes, can be classified as biodegradation or metabolic transformation. Metabolic bio-transformation can also cause alternations that give rise to compounds which are more toxic than molecules from which they are derived. Further it has been shown under controlled laboratory conditions that environmental contaminants such as heavy metals, PCBs and pesticides are sensitive with the immune system of fish (Vos et al., 1987). This means that an increase in infectious diseases in areas contaminated with immunotoxic chemicals in Bangladesh could be attributed at great extent, to the immunosuppressive properties of these compounds. Pollutants may interact with natural water substances, and with each other. In addition, their effect on organisms may be altered by the presence of other toxins. Hellawell (1986) comments that the effect of mixtures of pesticides may be more poisonous than predicted from the known effects of each one separately.
In Bangladesh in the recent years growing use of pesticides and fertilisers by farmers, unaware of the negative effects of agrochemical, pose a big challenge to health, environment and the declining economy of the country. cropland clearly is a major source of sediment and the sediment resulting from soil erosion is regarded as the largest pollutant that affects water quality. There are about 20, 00 private pesticide dealers throughout Bangladesh coercively marketing 64 kinds of pesticides. their sales of pesticides more than doubled between 1985-90. In 1985-86, 3063 metric tons of were used in Bangladesh. During 1990-91 that figure reached 6948 metric tons. 18 per cent annual increase trend is alarming (Ramaswamy, 1992). Ninety per cent of the agricultural use of pesticides are for the newly introduced high variety rice (IRRI) and wheat, whereas the traditional varieties require almost no chemicals.
Some extremely hazardous pesticides are used in the country, although these are prohibited in the producing countries. These pesticides are carcinogenic (producing cancer), mutagenic (causing genetic damage), teratogenic (damage foctus), and allergenic (Table:1). In the study of chemical carcinogenesis, two important ideas have evolved. First many carcinogenic chemicals irreversibly alter cellular DNA, resulting in a heritable change; such chemicals known as mutagens. Second, cancer formation is a multiple process, with the simplest model being that initiation and promotion. In this multistep process, at least one step must involve a change in DNA; the additional steps affect the growth and development of tumour cells. Some examples are cited as follows:
ORGANOPHOSPHORUS PESTICIDES: (diazinon, malathion, diptrex phosphamidon, carbofuran, NOGOS, etc.)
The group includes a large number of insecticides, herbicides and fungicides - containing an organic structure made up of carbon atoms arranged in a straight chain or ring. These insecticides work by interfering with the function of nerve cell. The health effects of chronic organophosphates exposures to animals and man suggests immune dsfunction, and the occurrence of hematopoietic tumours, especially lymphomas. Epidemiological studies of Organo phosphates exposed populations show lymphomas in farmers, lymphomas in grain mill workers, lymphomas in resin workers ( Newcombe et al, 1994). Evaluation of in vitro human natural killer (NK) cell and cytotoxic T lymphocyte (CTL) activities in the presence of Organo phosphates shows that the cytotoxic functions of these cells are significantly inhibited by some organophosphate compounds. Newcombe et al (1994, American Chemical society) suggest the following results due to organophosphates exposures:
- Organophosphorus -induced Immune dysfunction;
- Organophosphorus Suppression of Natural Killer (NK) Cell Activity;
- Organophosphorus Suppression of Cytotoxic T Lymphocyte (CTL) Functon;
- Immune Dysfunction and Lymphomas,;
- Esterase deficiencies and Hematopoietic tumors;
- Organophosphorus Inhibition of monocyte Esterase Activity;
- Oncogenic Viruses and Organophosphorus-Induced Mutations;
- Immundeficiency and Lymphomas;
- Immune deficiencies and epstein-Barr virus Infections;
- Organophosphorus-Induced Chromosomal Aberrations;
- Ataxia Telangiectasis and Lymphoma.
In the healthy nervous system, insect, animal or human, an activated nerve cell stimulates the next in line by releasing the enzyme acetylcholine, which flows across the tiny gaps or synapases that separate nerve cells. Once the nerve impulse has passed across the synapse another enzyme, Cholinesterase, acts to stop the message reverberating endlessly across the synapse. Altstair Hay, a chemical pathologist at the University of Leeds, states that both voluntary muscles and involuntary muscles (heart, lungs, stomach and uterus etc.) can go into spasm in response to the absence of Cholinesterase (Bartle, 1991). The unchecked nerve message to the voluntary muscles results in tremors in all muscles a person can think of moving. The unchecked signals to the involuntary muscles can result in heart attacks, stomach cramps and vomiting, excessive menstruation and spontaneous abortion in women, impotence and sterility in men, loss of sphincter control , increasing excitement and fearfulness (Bartle, 1991). For those who survive exposure to organophosphates the impact on their lives and bodies is enormous. Thousands of deaths and harm cases by pesticide poisoning in Bangladesh are neither registered, nor reported. But scattered reports of poison and deaths are regularly appear in local newspapers.
In Bangladesh about one third of pesticide consumption consists of organophosphate Diazinon , which appears a serious challenge to all living beings. Hellawell (1986) showed in standard comprehensive toxicity tests that a mere 5 to 51,000 parts per billion (ppb) organophosphosphorus pesticides in water are intolerable to fish. Fish are the best indicator of water health and decrease in fish quantity and increasing in diseases reflect that Bangladesh has arrived beyond the tolerable range. Besides, the main source of drinking water in the urban areas is surface water. Whereas the groundwater is replenished by surface waters. The most serious threats that chemical contaminants from industry and agriculture pose is to groundwater, which is virtually impossible to purify once contamination has occurred, since the microbes that normally break down organic pollutants need oxygen, from which groundwater is cut off. Recent (1993) example is in West Bengal, where several deaths are reported from arsenic contaminated ground water (see also chapters: Heavy Metal Pollution in Bangladesh and How Safe is Drinking Water in Bangladesh).
THE DIRTY DOZEN
The Pesticide Action Network (PAN) in U.K. since 1985 launched the "Dirty Dozen" campaign with the intention of stopping 12 particular controversial pesticides : 2,4,5-T, endrin, aldrin, paraquat, chlordane, lindane, DDT, campachlor, chlordimeform, ethylene dibromide, DBCP, dieldrin, ethyl parathion and pentachlorophenol. It is reported in the local press in Bangladesh that there is a widespread distribution of banned pesticides, especially the highly toxic "Dirty Dozen". There are also many pesticides sold in the market without names or under false labels. Unknown diluted varieties rarely contains any instructions on health hazards are sold to unaware farmers, who use their naked hands to spray pesticides and preserving the rest on the floor along with vital household goods and use them for drinking water and food (Erler, 1985). There are no statistics on pesticide causalities, although reports on deaths and sufferings or chronic effects are common in Bangladesh.
Some analysis in Bangladesh show alarming pollutants in fish like DDT, DDE, DDD, heptachlor, lindaine, dieldrin, aldrin, heptachlorepoxiode, PCBs and mercury ( BCAS, 1990). Even small amounts - no more than a few parts per billion of water - of DDT and many other pesticides can stunt or stop reproduction in some species. A concentration of eight per million in the ovaries of sea trout in an estuary off the Texas coast prevented spewing. As little as one part in ten billion of DDT in water severely cut the growth rate of oysters, and two parts in ten billion kill commercial species of shrimps and crabs (Echolm, 1976).
The author recently visited north-east Bangladesh (Syleht District) hilly areas where mainly tea is produced and the low lying areas of Surma Basin with its paddy fields and one of the main centres of inland fisheries of the country in numerous beels and haros (wetlands). It was surprising to acknowledge that the tea gardens that used to be alive with birds use to live in harmony to nature were covered in deep silence. From official reports it is known that chlordane and heptachlor etc. are widely applied here, whereas animal tests have shown to be a mutagen and carcinogen, and to cause damage to the nervous system, the liver and the developing embryo/fetus, which recommended by the World Bank not to be used as a pesticide. Chlordane was also banned for use on food crops by the EPA (USA) in 1975. Since the extensive use of pesticides - insecticides and herbacides (mainly dirty dozen) the indigenous birds which used to live of insects perished. Fish diseases and the decline of inland fisheries are possibly related with the use of hazardous pesticides.
Pesticides and other chemically contaminated rain waters enter low lying rice fields and inland fish producing waters (rivers, beels, haros). These haros and beels (wetlands) are a major wintering and resting site for many indigenous and migratory birds. About 330 species of plant, 270 species of bird and 120 species of commercially important fish are exposed to danger. A comprehensive study on the destruction of natural environments and ecosystems is not available. But the recent increase in fish diseases and human sufferings indicate an alarming situation. A study of soils (Dept. of Environment, 1989) after 336 days use of organochlorine pesticides shows the soil still contains 35% Aldrin, 37% Dieldrin, 43% Lindane (Ó-HCH), and 30% Hepatchlor. The organo-phosphate pesticides after 80 days of spray show soil contains 15% Diazinon, 15% Parathion, 8% Dichlorvos (NGOS), and 5% Phosdrin (Mevinphos).
Chlorinated hydrocarbons (organochlorine compounds) were the first generation of pesticides called wonder drug, introduced following the Second World War which comprise DDT, Dieldrin, Heptachlor epoxide, and others. They are designed to kill insects and which, as broad-spectrum poisons, having an extreme range of biological activity, stability and affinity for living organisms, also inflicted heavy mortality upon vertebrate wildlife. The insecticide (DDT) do not easily break down in the environment, but build up in the body fat of those who consume it.
In 1972 the use of organochlorine pesticides was banned in the USA and many European countries. The Pesticide producing plant at Chittagong yearly produces yearly (1987-88) 729 metric tonnes of DDT. Bangladesh extensively uses DDT, repeating the well documented experience of Europe and the USA of sanitising the soil, contaminating groundwater, depleting the wildlife and repeatedly increasing resistant pest strains. Unaware farmers in Bangladesh in an effort to increase crops overuse pesticides - many insecticides wipe out not just the target species but all insects that they come into contact which include the natural predators of the target insect. The target insects that have escaped regroup, breed anew and recolonize in the sprayed area. The farmers try stronger doses of known or unknown varieties of pesticides from the market and in course of time most possibly mutant species develop which are resistant to insecticides. Eighteen species of animal are reported to have been lost in this century in Bangladesh and there are also over 300 species considered to be rare or doubtful occurrence.
It is not imaginable to predict the result of one of the most man- made hazards of this century. Most of the users are unaware and the government is not capable to monitor environmental policies. The environmental plans and priorities in Bangladesh are conspicuous by their absence and where they exist they are inadequate and unforceful.
There are no facilities to monitor pesticides and to control pollutants in Bangladesh. Any government regulation on Maximum Admissible Concentration (MAC) or ban on illegal chemicals without modern laboratory facilities and increase awareness on sustainable environmental incentives will remain ineffective.
The history of pesticide uses illustrates that additional problems are created either by the rapid resurgence of the treated pest population or by the elevation of minor pests to the role of secondary or major pest status. Furthermore, insecticide applications reduce not only the pest population but also populations of natural enemies, with a resultant increase in pest population. There are many examples of unintentional damage to nontarget species:
the drift of herbacides and insecticides onto sensitive crops or those intended for animal feeds; the reduction of beneficial soilmicroflora by application of fungicides or herbacides to the above ground portions of the crop; killing of wild life; the contamination of root crops from last years insecticides or herbacides application; sickness and death of livestock feeding in pastures on which highly toxic materials drifted following application of to adjacent crops; and, finally, the accidental poisoning of persons, including children, from improperly stored pesticides.
A dependence on pesticides results in increased human-made pest problems, environmental damage, and potential hazard to human themselves. Generally, pest control methods available today fall into six categories:
1. Chemical control: the control of pests by the use of pesticides
2. Biological control (biocontrol): the reduction of pest numbers by predators, parasites, or pathogens
3. Cultural control: the use of farming or cultural parasites associated with crop production that make the environment less favourable for survival, growth, or reproduction of pest species
4. Physical and mechanical control: the application of direct or indirect measures that kill the pest, disrupt its physiology other than by chemical means, exclude it from area, or adversely alter the pest's environment
5. Host-plant resistance: the use of and development of plants that are resistant to attack by insects, disease organisms, nematodes, or birds.
6. Regulator control: the prevention of the entry and establishment of undesirable plant and animal pests in a country or area and eradication, containment, or suppression of pests already established in limited areas (quarantines).
The eco-farmers of Europe have made considerable advance in crop production without using chemical method of pest control. The traditional varieties of crop plantation in Bangladesh are host plant resistance, biological, physical and cultural controlled, that the farmers inherited since thousands of years. But recently introduced high yield varieties require vigorously chemical control method.
FERTILISERS AND HYVs (HIGH YIELD VARIETIES)Recent all major newspapers in Bangladesh came out with headlines and editorials in Bangladesh on import of toxic fertilisers from the USA. By June 1992, the toxic fertiliser was distributed in 12 districts and was suspended only when the press took up the issue and the result of an US lab test revealed that the 6.9 per cent lead and 0.05 percent cadmium found in the samples would be highly toxic. But the Bangladesh Agricultural Development Corporation gave any explanations to the dealers or the farmers in this regard (BCAS, 1992). A daily news paper in Dhaka revealed that 14,400 metric tonnes of toxic TSP fertiliser was unloaded sometimes in the first week of November 1992 at Chittagong port. The Third World has become direct and indirect dumping ground of hazardous wastes of industrial countries. The developed countries, pressed by their mountains of waste and increasing disposal costs, began to look for opportunities to export the problem. The European Environmental Bureau pointed out in a conference held in December 1987, the EC has safe disposal facilities for only 10 million tonnes of hazardous waste per year, or one-third of the total generated. Twenty million tonnes of hazardous waste per year will be looking for a resting-place. A number of European or North American business or municipal authorities have sought to transport toxic wastes to certain Third World nations with little or no consideration of the possible consequences for local population. The cost of transporting toxic wastes to developing countries is only a fraction of the cost of safely incinerating or storing them in the in the West and meeting government regulations in doing so. The local authority at the disposal sites are unaware of the composition of the wastes and in most cases they are unable to analyse the composition of the hazards.
Around 75 per cent of the cropped area in Bangladesh is producing rice and rice yield has been increased considerably since last twenty years with the increasing growth of high yielding varieties (HYVs) but the poverty has not been decreased. The price for producing rice has been rapidly increased and the farmers do not obtain the real return. Recent agricultural production has been achieved at the cost of intensive use of fertilisers, pesticides, construction of embankments to avoid seasonal flooding by sediment laden rivers, and increase in tubewells, low-lift pumps for irrigation. Increasing agricultural cost has produced more poor farmers, only the rich farmers and landlords are benefited.
The traditional varieties of rice such as Aman, Boro ,Aus etc. are replaced in many areas by HYVs. At present farmers complain declining yield of HYV rice despite increasing use of chemical fertilisers and pesticides. According to Agricultural Development Department, Government of Bangladesh about 244,000 tonnes of fertilisers were distributed in 1971-72, whereas it increased to 1588,000 tonnes in 1987-88. After the construction embankments, where the HYVs are cultivated, agricultural land does not receive fresh fertile sediments, algae and water that keep ground water level high during dry season, depleting natural soil to nutrients poor soil. The loss of vital nutrients like illite, montmorillonite clay minerals, silt, organic matters (nitrogen supplying algae) compensated by chemical fertilisers. Now the new agriculture can survive in Bangladesh as long as it continues to be supplied by agrochemicals, and on the other hand, the basic soil infrastructure will be destroyed so that there will be little inherent fertility remaining. It is now forgotten that Bangladesh is gifted with enormous fresh fertile soils and organic matters (2.4 billion tonnes annually) which usually deposit in floodplains (main agricultural land). But after the introduction of HYVs numerous structural measures to control intrusion of flood water deprived the land from the flow of natural fertilisers. It may be mentioned here, after each major flood, when flood water crossed the embankments, a record crop yield was registered in Bangladesh (Anwar, 1992).
The increasing use of inorganic nitrogen fertilisers not only kills existing fish stocks but also responsible for the proliferation of widespread water pollution. Nitrates in themselves are not especially dangerous, although in the presence of certain bacteria in the digestive tracts of infants and animals they convert to highly toxic nitrites, affecting oxygen utilisation ("blue baby syndrome"). Nitrates themselves may be carcinogenic and in adults' digestive tracts they produce nitrosamines, proven carcinogens. Nitrogen enrichment of rivers, streams, beel, haros encourages the growth of algae, which in process of decay causes deoxygenation and the extremetion of most aquatic life.
The excessive use of chemical fertilisers (ammonia, nitrates and phosphates) to cultivate HYV rice, indeed, decreases the take-up of natural nutrients, diminishes the ability to hold water and accelerates erosion. The high deposition of ammonium results in an accumulation of ammonium in soil and in a simultaneous leaching of essential nutrients as potassium, calcium and magnesium from the soil and also leads to damage the root system. The rate of higher productivity of HYV varieties is based on the capacity of photosynthesis and the maximum capacity has arrived. The government and many organisation in Bangladesh have reported that the deterioration in soil fertility is attributed to continuous monocropping of rice, particularly HYV rice. According to the Ministry of Environment and Forest (1991), Government of Bangladesh, since the last decade average HYVs and irrigated rice yield have been dropping. Year round transplanted rice cultivation keeps the land water-logged continuously for many years. This, in turn, leads to the formation of toxic compounds in soil, loss of essential nutrients like zinc and sulphur through deep percolation, and the spread of soil-borne diseases which thrive in this water-logged , and which become difficult to eradicate. About 3.9 million ha and 1.74 million ha of land is deficient in sulphur and zinc respectively. This has caused a crop reduction of about 10 per cent on an average. Besides there is a rapid decrease in other important crops such as oil seeds, lentils, vegetables etc. The farmers of Bangladesh use to plant them traditionally since thousands of years. Now Bangladesh has to import these items legally or illegally across the borders.
One of the rice co-operatives in Philippines complains about the high cost for the use of fertilisers and pesticides compared to traditional variety - IRRI produces 8 tonnes per hectare which is only 1.75 tonnes higher (Mooney, 1985). There are many commercial advantages to producing entire plantations of uniform, high yielding crops, clonally propagated crops are six times more vulnerable to pests and diseases than their seed-bred counterparts (ATAS, 1982).
The Green Revolution which was to feed the world hungry is destroying the genetic base of the food supply. International Organisations showed that an increase in hunger and malnutrition characterises these areas (Graffin et al., 1976). In Bangladesh consumers complain very high prices of declining quality of vegetables and beyond the reach of poor people. Farmers have to compensate high cultivation costs due to rapidly increasing use of costly fertilisers and pesticides (Chinta, 1992). The imported technology with the high demand of water, fertilisers and pesticides a narrow gain of a few hundred dollars can be achieved. Recently protesters (Indian farmers) attacked and damaged parts of a seed processing plant of the US seed giant Cargill of Minneapolis being built in Karnataka in India (New Scientist, 31 July, 1993). M. D. Nanjundaswamy, an agricultural scientist and president of the KRRS says that multinational seed companies are gene thieves, buying in seed from farmers, treating it and selling it back at a hefty profit. The poor farmers can not afford to buy seeds, pesticides and fertilisers at a rapidly increasing price , and at the same time food production is declining.
Manipulation of IRRI evolution is going to make the same mistake as it happened in Formosa at the beginning of this century. The danger of monoculture first became evident with the Irish Potato Famine of the 1840s and 50s. Monoculture, in turn, creates a market for crop chemicals. More advanced varieties of seed will lead to more toxic chemicals, greater risks for farmers, achieves only environmental damage, more chemical residue in food system, increasing production cost and danger of crop loss.
In USA more than a billion pounds of active toxic ingredients are poured onto crops every year, only one per cent hits its target. Since the rise of pesticides, 30 species of weeds and 447 species of insects have become tolerant of the chemicals designed to thwart them. Most of the HYVs producers are also the leading multiorganizations of chemical industry - Sandoz, Upjohn, Limagrain, Cargill, Volvo, ICI, France Mais, Dekalb-Pfizer, BASF, Royal Dutch/Shell, ITT, and Ciba-Geigy, whereas only six are traditionally seed producers. The Royal Dutch/Shell is the highest producer of pesticides and at the same time is the largest seed producer of the world. In fact, the short and long term strategy of the supplying industry is to maximise the use of chemicals and use new biotechnique to broaden the applicability of pesticides (Mooney et al., 1988). Chemical companies recognise that there is a bonanza awaiting manufacturers who can create seeds like herbicides. It is undoubted that "the green revolution" has opened the world wide market of the agrochemical industry. Third World expenditure on pesticides in some $ 40.0 billion annually, which is the equivalent of the net transfer of capital from Third world
to the developed countries (The World Bank).
There were about 30,000 rice varieties cultivated by farmers in the Indian sub-continent and at present only 15 varieties account 75 per cent of rice cultivation. Pat Mooney and Cary Fowler, the Noble Prize winners of 1985, described as "genetic erosion". Most prominent of all is the environmental erosion. Not only are the final days of the twentieth century witnessing the genetic erosion of crop resources - a loss of more than half of the diversity of major food plants in a scarce of three decades - we are also observing soil and atmospheric erosion. The new HYVs are unstable to environment, replacing the environmentally sustainable plants that were preserved by our ancestors since thousands of years. Mooney and Fowler (1991) termed HYVs as "threat of seeds of hunger" which threatens the present and future generations.
It may not be too late for Bangladesh to encourage improve farming techniques for traditional varieties under regulated flash of annual flood water in the agricultural land, reducing reliance on chemicals, improving the quality and health aspect of food production, protecting water supplies and creating a more congenial environment for human beings and habitat.
Ali, M. Y. (1992): Importance, Problems and Potentials of Fisheries In Bangladesh; Training Manual on Environmental Management in Bangladesh; Edt. Md. Reazuddin; Dept of Environment, Govt. of Bangladesh.
Ali, M. Y. (1994): Fisheries and Environment; Environment and Dev. in Bangladesh, V2, University Press Ltd., Dhaka, Bangladesh.
American Chemical Society (1994): Biomakers of Human Exposure to Pesticides; ACS Symposium Series 542, edts. Saleh, M. A., Blancato, J. N. and nauman; C. H.
Anwar, J. (1992): The Ganges Brahmaputra Delta Plain: A Challenge; The Bangladesh Observer, Dhaka, Bangladesh.
ATAS Bulletin (1982): Pesticide Resistance and World Food Production; Imp. College Centre for Environmental Technology, London.
Bartle, H. (1991): Quite Sufferings of the Silent Spring; New Scientist, U. K., May 1991.
BCAS (1990): Bangladesh Env. News Letter; n. 6, v 2, Dhaka, Bangladesh.
BCAS (1992): Bangladesh Env. News Letter; n 4, v 3, Dhaka, Bangladesh.
Brevik, E. M. (1981): Organochlorine Residues in Fish from Lake Mjosa, Norway; Bull. Env. Contam. Toxicol., 26, 679.
CHINTA (1992): The Increase Use of Fertilizers and Pesticides and the Effect of Increasing Higher Price in Bangladesh; in Bengali; January 31, 1992, Dhaka, Bangladesh.
CIDA (1989): The Environment and Natural Development in Bangladesh; Canadian International Agency.
Department of Environment, Govt. of Bangladesh (1989): Bangladesh Environment; in bengali, Dept. of Environment, Govt. of Bangladesh, Dhaka.
Echolm, E. P. (1976): Losing Ground; W. W. Norton & Comp. Inc., New York.
Erler, B. (1985): Tödliche Hilfe; Dreisam Verlag, Freiburg, Germany.
Fairchild, E. J. ed.(1978): Chemicals and Pesticides - A Handbook of the Toxic Effects; Castle House Publications Ltd., London.
Fowler, C., Lachkovics, E., Mooney, P. and Shand, H. (1988): The Laws of Life; Development Dialogue, Uppsala.
Greffin, K. and Khan, A. R. (1976): Poverty and Landlessness in Rural Asia; World Employment Programme, Geneva.
Haslam, S. M. (1991): River Pollution: An Ecological Perspective, Belhaven Press, London.
Helawell, J. M. (1986): Biological Indicators of Freshwater Pollution and Environmental Management; Elsvier Applied Science Publisher, London.
Hodgson, E. and Levi, P. E. (1987): Modern Toxicology; Elsvier, New York.
Holden; A. V. (1964): The Possible Effects on Fish of Chemicals Used in Agriculture; J. Proc. Inst. Sew. Purif., 4, 361.
Hossain, S. S. (1991): Use of Pesticides for the Conservation of Dry Fish in Bangladesh; in Bengali, Chinta, April, Dhaka, Bangladesh.
Lunsford; C. A. (1981): Kepone Distribution in the Water Column of the James River Estuary - 1976-78; Pestic. Monit. J., 14, 119.
Möcker, V.,ed. (1988): Was Sie schon immer über Umweltchemiekalen wissen wollen; Kohlhamer Verlag, Berlin, Germany.
Mooney, P. R. (1985): Saat-Multis und Welthunger; Rowohlt, Hamburg, Germany.
Mooney, P. and Fowler, C. (1991): Die Saat des Hungers; Rowohlt, Hamburg, Germany.
Murty, A. S. (1988): Toxicity of Pesticides to Fish, Volume 1; CRC Press, Inc., Florida, USA.
Nandy, G. (1996): Shrim Export Faces Loss, Lobster Farmers Face Problems; Dhaka Courier, March 8, 1996.
Newcombe, D. S., Saboori, A. M., and Esa A. H. (1994): Chronic Organophosphorus Exposure; in Biomakers of Human Exposure to Pesticides, edt. M. A. Saleh et al., American Chemical Society, Washington DC.
New Scientist (1993): Seeds of Dissent in India over Foreign Gene Thieves'; Bupesh Mangla, p 8, 31 July, 1993.
Nicholson, H. P. (1967): Pesticide Pollution Control; Science, 158.
Overstreet, R. M. (1988): Aquatic Pollution Problems, Southeastern U.S. Coasts: Histopathological Indicator; Aquat. Toxical., n 11.
Ramaswamy, S. (1992): Pest Control and Environment; Bangladesh Agricultural Research Council, Dhaka, Bangladesh.
Sindermann, C. J. (1983): An Examination of Some Relationships between Pollutants and Disease; Rapp. P.v. Reun. Cons. Int. expol. Mer., n 182.
Vos, J. G. and Van Loveren (1987): Immunotoxicity testing in the rat; Burger edt.; Environmental Chemical Exposures and Immune system Integrity, Adv. in Mod. Environm. Toxicol., v 13, Pricnecton Sc. Publ.