arsenic poisoning in Bangladesh/India

Presence of high concentration of arsenic in drinking water in excess of acceptable limit has become a major concern in Bangladesh. A number of government agencies and NGOs have been conducting testing of tubewell water for detecting the presence of arsenic. According to WHO report, groundwater of 41 districts of Bangladesh has been affected by arsenic contamination. Based on information from the DPHE UNICEF national testing programme, 29 per cent tubewells across the country contain arsenic above the maximum permissible level (>0.05mg/L).

About 40 million of people are at risk of arsenic contamination in which 7000 (approx.) people are already arsenic-affected.Arsenic in drinking water is a new hazard in Bangladesh and is an extremely complex problem. Much is yet to know regarding its real risk to human life. It is well known that arsenic in any form is toxic when absorbed in human body beyond the tolerable level. Arsenic poisoning is causing serious health hazards to the affected persons, and at the same time it is creating a lot of socio economic problems. But overall awareness is very low.

The situation has given rise to misinterpretation and misconception due to lack of awareness even in the educated circles. Due to our ignorance, some people are mistaking skin disorders resulting from arsenosis for leprosy or other contagious diseases. Victims are not allowed to attend any social and religious functions. Sometimes affected children are prevented from attending schools. Affected families are refused to take water from the neighbours' tubewells. The women are the worst sufferers because they are more malnourished than men, so are less able to deal with arsenic that invades their bodies.

This has resulted in a lack of understanding in men and as a result many have divorced their wives. Sometimes, husbands' families are not agreed to take meal from affected women. It does not end there for girls who succumb to the poison. They are finally not accepted as wives. Of course it can work the other way round too, and a man with arsenicosis may not be able to find a bride or he and his family is ostracised.

In some cases affected young unmarried women and men are advised to remain unmarried. Even victims are denied to get jobs. Arsenic disease is more prevalent amongst the poor people. These victims become incapable of giving hard labour and getting curative measures, and therefore, face a distressed future in the vicious cycle of increasing poverty and ill health.

Further, this is compounded by negative social attitudes. Unfortunately victims are sometimes treated as untouchable and as if they had an infectious disease.There is no end to the pain. In other words, to be poisoned by arsenic is not only a death sentence but a tragedy for the families too. It is also a tragedy for the nation, especially if men are victims, for it also harms the development efforts of the nation as victims are incapable of contributing to the country's economic growth. Such is the debilitating nature of the disease. On the other hand, there are people who see arsenic contamination of the groundwater as a means and an opportunity to make money.

A few case studies reported by Dhaka Community Hospital pointed to the magnitude of arsenic problem and its social effects. A college-going young man of Khoksha in Kushtia has spent about Tk. 40,000 to cure his skin ailments, but the treatment had no results. After he was identified as an arsenic patient, he just looked dazed in shock and despair. A young village woman of 21 years in Noakhali has experienced a lot already in life. She was divorced soon after her marriage because arsenic poisoning caused nasty scars on her skin. She has lost her zest for life. Even her parents now wish death to their beloved daughter.

There are many more such stories in the arsenic-affected areas.Avoiding arsenic contaminated water can alleviate the arsenic calamity. The way to avoid arsenic poisoning is to avoid intake of both arsenic contaminated food and drink. The people of the affected areas can drink surface water after its filtering and boiling. Various technologies are under consideration to reduce arsenic content below safe limits. But yet there is no foolproof solution to treating and obtaining cost effective arsenic-free water, particularly within the reach of the poor. In this regard social awareness building can play an important role in the safety of our health.

The conscious family and society must come forward first to take cue from the poor victims. Sufferers must get proper care and education. Government, donor agencies, private organisations, NGOs, educational institutions, press etc should jointly come forward to help mitigate the arsenic problem in Bangladesh. Health professionals like doctors, toxicologists, pharmacists, paramedics, nurses and radio, television can play key role in creating public awareness.

Source: The Independent, 4 March 2000

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3. Arsenic Threat

A LEAST developed country like Bangladesh, saddled as it is with numerous problems, has been burdened with another and quite a formidable one because it involves drinking water that is basic to life and living. Arsenic presence in underground water - used heavily in Bangladesh for drinking and all household activities - was detected some six or seven years ago. The problem then was thought to be limited to certain areas but later this notion was proved wrong. Subsequent investigations and reports disclosed more and more areas to be under arsenic contamination. High percentages of arsenic contamination in ground water have been detected in so many places that practically the menace now extends in varying degrees to nearly all of the country. According to the latest research, nearly 70 million people out of the country's about 130 million people - meaning more than one half of the entire population - fall in the arsenic risk zones. This is a deeply worrying figure to say the least.

Arsenic's effect on health does not show up readily. People in the affected areas have been drinking such contaminated water for years together not suspecting the effects of the same on their health. The tell-tale lesions on the skin and other physical dysfuntions from long-term exposure to arsenic start showing up only after some years. Therefore, the menace has been quietly creeping up on people when its victims remained rather in the dark about it.

The latest findings pointing to the extent of the health hazard posed by arsenic in water leave no room for complacence. The government must act quickly and decisively to counter this very serious health problem with the seriousness it deserves. Human lives not in hundreds of thousands but millions are now involved and no administration worth its name can remain a silent spectator to such a dangerous threat to health that engulfs the population. Unfortunately, the government's reactions so far have been mainly limited to awareness building and very limited attempts to provide some safeguards. However, these actions are surely too inadequate and meaningless when extensive programmes need to be started in the affected areas to provide the means of using relatively arsenic free-water.

One may say that this is easier said than done. But the reality is that technologies are available and the costs of the same are not prohibitive that people on their own will not want to use them; people fearing for their lives are found willing to even exceptionally spend money to steer clear of danger. Why then the authorities are dilly-dallying to make available filtration devices that can immediately provide safety against arsenic is a question worth asking. Such devices are being used widely in even parts of neighbouring India where arsenic is a similar public health issue.

Government bodies should not only distribute these devices extensively throughout the country but also try to do the same at subsidised costs to ensure that a device reaches every affected household in keeping with the government's commitment and budgetary provisions of safeguarding people's health. Besides, several natural processes are also available that can substantially filter arsenic from water. The devices and the processes need to be immediately introduced in affected areas under crash programmes. The official thinking perhaps is that even cheaper technologies and processes will be devised and then the campaign against arsenic can start in right earnest. This is a suicidal thinking because human lives cannot be left to high risks for the rationale of applying cheaper technologies.

Meanwhile, there is also the very pressing need to go all out for harvesting rain water. Rain water is the freshest natural form of water available and many countries round the world harvest rain water in great quantities to meet the needs of their population. The use of rain water in Bangladesh is still very limited although it can go some way in providing relief from arsenic contamination. Rain water in good amounts can be harvested throughout the greater part of the year in Bangladesh when rainfall is found to be frequent. Together with rain water, use of surface water of rivers and water bodies - treated for impurities - will have to be considered to face up to the arsenic threat.

Source: The Financial Express, 4 March 2000

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4. A market basket survey of inorganic arsenic in food

Schoof, R., L. Yost, et al. Food Chem Toxicol 37(8): 839-46.

Dietary arsenic intake estimates based on surveys of total arsenic concentrations appear to be dominated by intake of the relatively non-toxic, organic arsenic forms found in seafood. Concentrations of inorganic arsenic in food have not been not well characterized. Accurate dietary intake estimates for inorganic arsenic are needed to support studies of arsenic's status as an essential nutrient, and to establish background levels of exposure to inorganic arsenic. In the market basket survey reported here, 40 commodities anticipated to provide at least 90% of dietary inorganic arsenic intake were identified. Four samples of each commodity were collected. Total arsenic was analysed using an NaOH digestion and inductively coupled plasma-mass spectrometry. Separate aliquots were analysed for arsenic species using an HCl digestion and hydride atomic absorption spectroscopy. Consistent with earlier studies, total arsenic concentrations (all concentrations reported as elemental arsenic per tissue wet weight) were highest in the seafoods sampled (ranging from 160 ng/g in freshwater fish to 2360 ng/g in saltwater fish). In contrast, average inorganic arsenic in seafood ranged from less than 1 ng/g to 2 ng/g. The highest inorganic arsenic values were found in raw rice (74 ng/g), followed by flour (11 ng/g), grape juice (9 ng/g) and cooked spinach (6 ng/g). Thus, grains and produce are expected to be significant contributors to dietary inorganic arsenic intake.

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5. Hydrogeological investigation of ground water arsenic contamination in south Calcutta

Chatterjee, A. and A. Mukherjee. Sci Total Environ 225(3): 249-62.

Typical clinical symptoms of acute arsenic poisoning have been detected in 1000 residents near a factory in P.N. Mitra Lane, Behala, South Calcutta, located in a thickly populated area manufacturing copper acetoarsenite (Paris-Green) an arsenical pesticide for the past 25 years. Soil around the effluent dumping point of the factory was exceptionally contaminated, with arsenic, copper and chromium concentrations of 20,100-35,500 mg kg-1, 33,900-51,100 mg kg-1 and 5300- 5510 mg kg-1. Arsenic and copper concentrations in bore-hole soils collected up to a depth of 24.4 m at the effluent dumping point, decreased with depth. Arsenous acid, arsenic acid, methylarsonic acid (MA) and dimethylarsinic acid (DMA) were detected in bore-hole soils up to a depth of 1.37 m, after which only inorganic arsenical compounds were present. A positive correlation was established between arsenic and copper authenticated the Paris-Green waste disposal site as the source of contamination.

Mechanism of ground water contamination from this disposal site had been probed by a systematic hydrogeological survey and the arsenic content of the tube-well waters in the surrounding areas. Hydraulic conductivity was maximum in the central part. The site for disposal of the effluent was a ditch located in the zone of discharge. Sparingly soluble Paris-Green cumulatively deposited in the waste disposal site is decomposed by micro-organisms to water- soluble forms and finally percolated to underground aquifers along with rain water through the discharge zone. The contaminant is currently moving towards WNW with ground water flow and the residents in the direction of encroaching contamination are insecure due to penetration of the contaminant

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6. SEARCHING FOR SOLUTIONS
by Sylvia Mortoza

Introduction

In Bangladesh today, more than 90 per cent of the population get their drinking water from the million plus tube-wells that were installed for the anti-diarrhoeal campaign. This was one of the few success stories in the public health sector for it helped reduce water-borne diseases. But tubewells are now dispensing arsenic-laced water, with the result that many people are showing arsenical skin lesions in the late stages of manifestation of arsenic toxicity. This came as a shock for no one was prepared for what could be a disaster - arsenic contamination. The source of arsenic is believed to be geological and most water samples show a mixture of arsenic and arsenate. None showed any methylarsonic or dimethylarsenic acid.

Water is one of the major means of transport of arsenic in the environment. Arsenic in the aquatic environment is predominant in places with high geo-thermal activity. Soil erosion and agricultural run-offs are also large contributors to the arsenic concentration in sediments. High arsenic levels have been reported to be associated with sediments and a potential exists that it may be released in hazardous amounts to the overlying waters. Industrial effluents are also a major source of arsenic to the environment. Arsenic and arsenical compounds are found in effluent from metallurgical industry; glassware and ceramic industry; dye and pesticide manufacturing industry; petroleum refining; rare earth industry and other organic and inorganic chemical industries. It finds an application in the manufacture of herbicides and pesticides. Other industries using arsenic include wood and hide preservatives; lead shot manufacture; phosphate detergent builder; and pre-soaks used in many fertilisers.

A chemical factory manufacturing several chemicals including the insecticide Paris-Green (acetocopper arsenic) was responsible for the contamination of wells in the southern part of Calcutta, India. Over 7000 people were consuming the arsenic contaminated water for several years but this fact remained unnoticed until September 1989. A few died and some of the victims were hospitalised while symptoms of arsenic poisoning were evident in many families living in the area.
As arsenic is a cause for skin, liver, lung and kidney or bladder cancer, it is a big headache for the nation. Due to this carcinogenicity of some arsenic compounds, the objective should now be to reduce exposure to arsenic contaminated water to a level as close to zero as possible, taking into consideration its health effects and toxicology, occurrence and human exposure, availability and cost of treatment technology, the practical quantitation limit of arsenic normally found in drinking water.

Addressing the problem

Various treatment methods have been adopted to remove arsenic from drinking water under both laboratory and field conditions. The major mode of removing arsenic from water by physical-chemical treatment methods. Various treatment methods include:

adsorption-co-precipitation using iron and aluminium salts
adsorption on activated alumina/activated carbon/activated bauxite
reverse osmosis
ion exchange
oxidation followed by filtration

Scientists and health and water experts have intensified their search for treatment methodologies and reliable alternative sources of water supply. The United States Environmental Protection Agency (USEPA) have summarised coagulation with iron and aluminium salts and lime softening as the most effective treatment process for removing arsenic from water to meet the interim primary drinking water regulations standard of 0.05 mg/L [30]. That regulatory agencies are reviewing maximum allowable concentration levels in drinking water is comforting but, as arsenic contamination of ground water and the possibility of poisoning is too alarming to wait for solutions, it is essential to locate alternative sources.

The most logical answer would be to go back to using surface water sources. But as most of these sources are heavily polluted with bacteria, some simple method of disinfection is required. Boiling is an effective method of disinfection but, in Bangladesh, poverty, the difficulty with which fuel can be obtained as well as the current rate of illiteracy, prevents people from boiling water.

Solar decontamination

One alternative may possibly be solar decontamination. During the eighties, Professor Acra and his colleagues at the University of Beirut demonstrated how a wide range of microbes, including pathogenic bacteria and viruses, can be inactivated by exposing the contaminated water to sunlight. The process that was adopted was simple. All that was needed to make the contaminated water drinkable was to place the water inside a transparent glass container or a transparent plastic container and place it in the direct sunlight for two to three hours before drinking.

Although some doubt has been cast on the effectiveness of solar disinfection, the anti-microbial properties of sunlight have been known for a long time but it is only recently that solar radiation has been seriously proposed as a means for decontaminating water. All that is really needed is a reasonably constant and reliable source of sunlight. Several researchers have successfully demonstrated that sunlight will destroy much of the faecal bacteria present in contaminated drinking water but this process is especially effective if the water contains a sufficient amount of oxygen. An easy way to ensure this is to oxygenate the water before hand by mixing it with air.

That sufficient oxygen is needed to be effective has also been confirmed by other researchers in the UK who have shown that the effectiveness of solar decontamination of water is strongly dependent upon its oxygen status. Under controlled conditions, tests using water contaminated with either pure cultures of faecal bacteria, freshly voided faeces or raw sewage, were exposed to full strength, natural sunlight for several hours causing a substantial decrease in the bacterial count when the water was fully oxygenated. De-oxygenated water gave a far slower rate of decrease.

This means that over a period of several hours, sunlight and oxygen can act together to inactivate faecal bacteria. But the most significant practical aspect of this kind of solar "photo-oxidative" disinfection is that the oxygen level of the water must be kept close to maximum value during the exposure of water to full strength sunlight. Simple experiments undertaken by the team showed that a clear plastic or glass bottle, three-quarters filled with de-oxygenated water and capped, shaken vigorously for a couple of minutes will create air bubbles which will restore the oxygen level of the water to near saturation point. As microbes present in the water may consume the dissolved oxygen, this will reduce the effectiveness of this disinfection process. Therefore it is essential to shake each bottle a few times during the period of exposure to sunlight to ensure the oxygen level is kept close to maximum.

If the above routine can be followed to the letter, solar photo-oxidative disinfection will give consistently effective results provided the bottles are illuminated by sunlight of a sufficient intensity to give clearly defined shadows. Professor Acra's pioneering work has shown that the most favourable solar conditions are obtained between the latitudes of 15" and 35" North and South of the equator where sunlight is both consistent and predictable. With slightly less favourable conditions such as in equatorial and tropical regions (between latitudes of 0" and 15") it may not be as effective, due to the higher cloud cover, for this process is slowed down under cloudy conditions.

Nevertheless this technology has important implications for us for small-scale water treatment. Clear glass bottles however, restrict the penetration of short-wave ultra-violet component of sunlight which may lead to a slower rate of microbial inactivation, in which case clear plastic containers may be a better option. Glass containers may. however, be more durable for as the temperature rises during illumination, some plastic bottles may leach small amounts of plasticisers. Also they have a tendency to becoming increasing opaque to short-wave-length light from any prolonged exposure to the sun.

Water turbidity and colour may reduce the rate of bacterial inactivation. Such negative effects are insignificant except when the water is highly turbid or coloured when light transmission is reduced to less than half the surface value.

Solar photo-oxidative disinfection works better if the water source is relatively clear or when turbidity or colour does not substantially restrict the penetration of sunlight. This could be a problem in time of flood when water turbidity and colour normally increase, in which case the water will need some initial processing before being placed in sunlight. This could have an advantage for a proportion of the contaminating microbes would be removed prior to solar photo-oxidation.

Solar photo-disinfection can be carried out in the home by individuals, families or small communities without any need for a significant financial investment or external agency support - (the only requirement being a sufficient number of bottles to provide enough drinking water to meet each person's daily needs). Therefore, solar water treatment might be the answer to the problem of arsenic contamination for any low-income community where the cost of engineering solutions may prove too high.

In places where there is already a water supply system, it may make greater sense to install large solar powered water purification systems which can treat large quantities of water. Ultraviolet disinfection uses an ultraviolet (UV) light source enclosed in a transparent protective sleeve, mounted in such a manner that the water that passes through the flow chamber admit the UV rays and absorb them into the stream. These rays are able to destroy bacteria and inactivate many viruses. This kind of system disinfects the water without the need for adding chemicals and as a result, possesses some of the benefits of distillation.

It neither creates new chemical complexes nor changes the taste or odor of the water - and - it does not remove any beneficial minerals that may be in the water. However if the water is partially treated by the sediment process and carbon filter prior to passing through the UV flow chamber, it is more effective. Some of the bacteria that can be rendered ineffective through this process include - Leptospira interrogans (Infective Jaundice); Salmonella paratyphi (enteric fever); Salmonella typhosa (typhoid fever) Shigella dysenterai (dysentery); Shigella Flexneri (dysentery) Vibrio cholerae; Streptococcus; Staphylococcus; Escherichia coil; Hepatitis virus; Influenza virus; Poliovirus (poliomyelitis); Rotavirus and Bacteriophage (E.col) and yeast and fungi, all common in Bangladesh.

Acknowledgements:
ITDG UK
AIT, Bangkok, Thailand
Disaster Forum, Bangladesh

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7. ARSENIC REVISITED
by Sylvia Mortoza

Due to the more pressing problem of the flood and its aftermath, the presence of arsenic in the ground water has all but been forgotten. But this in itself spells danger for once forgotten, long-term problems of this nature are likely to be shelved until they regain their former virulence. Yet to a thinking person, it is hard to imagine how a problem as severe and serious as wholesale poisoning can be elbowed aside for any reason.

Narayn Shell What is especially astonishing and at the same time distressing is that this is the worst case of mass-poisoning the world has ever known, as such, the inability of most people to comprehend its portent is quite remarkable especially as this topic has caught the media's attention for some time now. The fact that inorganic arsenic has been a recognised poison since ancient times does not help us, for the presence of arsenic in ground water can only be viewed by this over-populated country as alarming. Yet, judging from the lack of correspondence in the press on this subject, few people, if any, seem unduly alarmed about something that could increasingly become a threat to life and limb, for them and their families. Yet the slow ingestion of arsenic over a long period of time can cause several forms of cancer like skin, liver, lung, kidney and bladder, as well as other diseases. Already the manifestation of arsenic-related illnesses is becoming alarming high in some parts of the country. Apart from the human cost, it is very likely to become an unwarranted large burden on the already hard-pressed health services. WHO estimates the time factor for the appearance of cancer is between ten to twenty years of exposure and, although this may mean it is too early to detect any increase in mortality from cancer, this factor cannot be ignored.

As long term exposure to arsenic can lead to hyper-keratosis, conjunctivitis, hyper-pigmentation, gangrene in the limbs as well as the cancers previously described, allowing people to have access only to contaminated water is inconceivable, and as arsenic is also in the food chain, the urgency must be given the recognition it deserves. Recent research from China (September, 1998), showed that rice grown on As-polluted soil contained 0.7 mg As/kg. Some plants such as mustard, cabbage, cauliflower etc. accumulate metals and metalloid (like arsenic). The major portion of absorbed arsenic is excreted through the urine (about 50 per cent); a small portion through faeces; skin; hair; and nails, and as it can be stored by the body in metabolically dead tissues and then slowly eliminated, some people may be tempted to play down the problem. That people handle arsenic differently, is known, for even here, although people are drinking from the same water source, one may be ill while others are not. But this does not detract from the fact that we are all in danger if we continue to drink arsenic-contaminated water.

A continuous consumption of arsenic-contaminated water can in time, result in three distinct types of chronic arsenic poisoning. The first begins with an irritation of the gastro-intestinal and upper respiratory tracts. The second is in an overgrowth of the Kasatin skin-structure with the development of numerous warts, ridges on the finger-nails, and coarseness of the hair and the third results in inflammation of the peripheral nerves. If this condition is allowed to persist, palsies may set in and the patient becomes listless.

As the only positive treatment for arsenic-poisoning is to find the source of the poisoning - and stopping it - the only way to avoiding further lethal doses is to stop drinking arsenic-contaminated food and water. Neither is arsenic-contaminated water suitable for washing clothes or bathing or for any other domestic purpose for arsenic can be absorbed through the pores too. Besides the waste water will be returned to the ground and re-absorbed into the soil. But despite this knowledge, efforts made to reduce dependence on arsenic-contaminated tube well water is not very much in evidence and this aspect of mitigation needs to be speeded up.

When people are faced with a problem of this size the easy way out is to deny there is a problem at all but ignoring it will not make it go away. Once we all take our collective heads out of the sand, only then will it be possible to find a solution. One way is to motivate the affluent section of society and persuade them to come forward to invest in small water purification plants, plants that are well within their capacity to provide. Although small water purification plants that serve around 1000 people may seem insignificant in a country with a population of 114 million, no effort no matter how small, can be termed insignificant even if at the moment it seems just a drop in the ocean.

If this can be the beginning of a programme where "self help is the best help," these little drops of water can soon become an ocean for with numbers affected by arsenic-poisoning increasing, there is clearly no time to waste even though there are supposedly various treatments available for removing the arsenic from the drinking water.

The problem with these is it is effected through a physical-chemical method which may not prove so easy or foolproof when dealing with a largely illiterate population. Besides none of them appear to be completely free from risk, so for general use, these may not be advisable because all leave behind a quantity of arsenic-sludge that is as dangerous as nuclear waste or radon. However, while scientists and water experts intensify their search for a solution, how we cope with a disaster of this kind will be up to us.

Although cheaper solutions which can render polluted water safe are available, if only the government agencies and the NGOs would take the trouble to go among the people and teach them the simple technology, this is not very likely for one reason and one only - there is no money to be made from imparting this "solar photo-oxidative disinfection" technology. All that is required is to show people how to fill transparent glass or plastic containers with water and place it in the sun for two to three hours before it is rendered safe to drink. This technology is based on research that has demonstrated that provided the water contains a sufficient amount of oxygen, sunlight will destroy much of the faecal bacteria present in contaminated water but, until some of the NGOs can be motivated to take this technology to the people, as things now stand, providing people with the minimum amount of water they need a day (estimated to be 15 litres), getting pure water to just those who have already succumbed to arsenic-related diseases, is a Herculean task beyond the capacity of the government.

In the face of this "No-win" situation, without the active support of concerned people, conquering arsenic poisoning is a task likely to overwhelm us. However for the moment it could be that we have received a reprieve of sorts for the extreme flooding may have "diluted" the arsenic in the ground water and driven out the air due to the replenishment of the water table. But do not think for a moment the problem has resolved itself, for once we start using the tube wells again - "mining" for water if you like - this is a problem likely to return - and with a vengeance - and it could even be we shall find arsenic in those places where there was previously none.

As we know the use of tube wells is unlikely to diminish, at least not in the forseeable future, in no time at all air will again get inside the aquifers to do its devilish work so, in other words, although the floods may be seem to be God-sent - in so far as arsenic is concerned - this will depend on how well we can prevent water from being extracted from below the earth's crust. Of course this is based on the assumption that the source is geological.

As a theory, the geological source is gaining in credibility for most of the water samples have shown a mixture of arsenic and arsenate. Soil erosion and agricultural run-offs are also believed to have contributed to arsenic concentration in sediments. High arsenic levels have been reported to be associated with sediments and the potential exists for it to be released in overlying waters in hazardous amounts. While it is acknowledged there may be more than one source of arsenic-contamination in Bangladesh, the size and extent of the problem seems to be pointing more to a geological origin as the most important.

Most of Bangladesh, except for the hills in the eastern parts of the country, is composed of a vast thickness of alluvial and deltaic sediments which can be divided into two main parts - the recent floodplain and the terrace areas. The floodplain and the sediments beneath them are only a few thousand years old and can be classified according to which of the river systems (Ganges, Brahmaputra, Tista and Meghna etc.) deposited them. The terrace areas, known as the Madhupur and Barind Tracts, and the sediments underlying them are much older than the adjacent floodplain (and may be as much as a million years old). Most of the arsenic is occurring in the younger sediments derived from the Ganges Basin.

Although arsenic is occurring in the alluvial sediments, the ultimate origin of the arsenic is probably in the outcrops of hard rocks higher up the Ganges catchment that were eroded in the recent geological past and re-deposited in West Bengal and Bangladesh by the ancient courses of the Ganges. At present, these source rocks have not been identified.

It is also important to understand that arsenic does not occur at all depths in the alluvial sediments. Although there is not enough evidence to draw firm conclusions, it appears that high concentrations are restricted to the upper 150 metres of the alluvial sediments and offers prospects of obtaining arsenic free waters from deeper layers. However, this remains to be confirmed.

The World Health Organization (WHO) has given advice on innovative alternative sources of drinking water such as pond sand filters, infiltration galleries, or Ranney (collector) wells and in some places rain water harvesting is being encouraged. As in some cases safe water sources are not available, and as arsenic removal processes, even as a short-term solution appears to be increasingly risky, due to the residual sludge, more permanent arrangements must be put in place. Although the sludge can be placed on a dung heap where the arsenic is converted by bacteria into a less toxic organic form, the sludge still has to be transported from its source to the dung-heap, which could expose women to poisoning.

UNICEF has also played its part in battling the problem by purchasing test equipment for zonal laboratories in the form of 500 field testing kits. The staff of the DPHE surveyed several wells with these field kits and later verified any positive results through analysis in the laboratory but as even these kits are subject to conjectures by environmental engineers who say that, coagulant kits and other quick removal options that are being distributed to people could, when such containers are cleaned, expose people to the precipitated arsenic based compounds.

They recommend that proper warnings be provided with these kits about the wastes generated and their proper disposal. This in itself may pose a problem as thrown on open dumps or unmanaged disposal sites, the arsenic may find its way back into the soils and eventually into the water.

The Royal Dutch Government is also funding projects for providing safe drinking water or for treating contaminated water. These projects include drilling deep tube wells in the arsenic affected districts and the construction of an arsenic removal treatment plant in Meherpur town. The sludge produced from the plant will be stored in a concrete tank which has a capacity lasting fifty years. Other organisations like UNDP took up a "TOKTEN Programme" which concentrated on the development of sensitive and selective Analytical Methods for Chemical Analysis of trace elements (at very low concentrations, e.g. 10-9g or less) such as Pb, Hg, Cd, As, Cr, Cu, Zn, etc in food, water, soil, air, human hair, blood, urine, etc, in the laboratories of the Atomic Energy Centre, Dhaka (AECD). The basic objective was to provide national services in time of need.

Suspected arsenic-poisoning cases were referred to Calcutta for diagnosis and treatment. Most of the field analyses were done in the SOES, Jadavpur University, Calcutta, in collaboration with the Dhaka Community Hospital. In 1993, under the Small-Scale Irrigation Project, the AECD was approached for analysis of groundwater samples for different parameters, including arsenic. In the face of increasing reports of arsenic-contamination and arsenic-related diseases, the concerned ministries and departments of GOB responded by constituting three different committees. What was the constitution of these committees is not known, nor was the Plan of Action (if any) revealed to the public. There was also an assumption by donor agencies that Bangladesh does not have the expertise to handle the problem. This pre-conceived notion was reinforced by the fact that the concerned GOB Departments for scientific and technical matters, suffered from this weakness, whereas other bodies did not.

This has resulted in a fragmented view of the arsenic problem as each discipline tried to solve it separately and in accordance with their own light so, instead of taking a coordinated view of the problem, individual efforts replaced the inter-disciplinary approach that was truly needed for a problem of this type. Under present circumstances, opinions are pouring into various government departments in an effort to help the government out of the problem.
One of the Terms of Reference of the National Committee for Research and Development on the arsenic problem, was to organise the analytical work and to ascertain which method should be chosen to investigate the nature of the problem. But the Government is being "helped" with outdated technologies (Kit method) and visible spectrophotometric method. It is now understood that the World Bank is setting up a modern laboratory, possibly at Khulna or Satkhira, for proper analysis.

The aquifers in Bangladesh are hydraulically interconnected. As a result of the Ganges water diversion by India, plus large-scale withdrawal of groundwater from deeper aquifers, the water table dropped with a gradual development of the drying zone. This caused rapid diffusion of oxygen within the pore spaces of the soil/sediments as well as an increase in dissolved oxygen in the upper part of ground water. As these oxic water or oxygen comes in contact with the 1st impervious layer within 30-50 meters, the Arsenic-laden pyrite is partially oxidized to form acid and becomes soluble, it is then released as arsenic, iron and sulphate, plus hydrogen (acid). The oxygen rapidly consumes the arsenic and forms sulphate, the iron acts as catalyst to further the decomposition of arsenopyrites.

These two-fold reactions released arsenic into the water.

The depositions are in 2 impervious layers under the modern delta formation of the Gangetic plain. One within 15 to 30 meters depth and the other one below 100 meters depths. These layers contain arsenopyrite, pyrite, iron sulfate, iron oxides as revealed by x-ray, diffraction, electronic probe, micro analysis and laser micro probe mass analysis. The Himalayas have pyrites and sedimentary formations as it is marine in origin. Marine conditions are the ultimate resting place for metals or elements or compounds. For example, the Indians recovered 150 kg of arsenic/year from the water of one solitary tube well. This means the arsenic found in the groundwater is certainly a geological source because no organic arsenic compounds were found at high concentration.

Bangladesh and the adjacent West Bengal have three aquifers: 1st one 2-15 meters; 2nd 40-80 meters; and the 3rd one below 100 meters. These aquifers are also hydraulically connected to the major streams in Bangladesh, especially the Ganges in the Northwestern region of Bangladesh. Ground water recharge is low due to less rainfall and upstream diversion of Ganges water by India. During the dry season, the water table falls to 25-30 feet below the surface.

Added to this, extraction of ground water for irrigation from 100 feet deep wells resulted in a drying zone within 200-300 feet below, maybe even more (Water Resources Policy in Asia) edited by Md. Ali (1985). That this newly introduced oxygen oxidised the arsenic in the arsenopyrites and released it into the water is now the accepted theory for when arsenic comes into contact with water and air, it forms hydrated arsenate which is highly soluble and very soft. The light pressure from the tubewell water helps to break down the hydrated arsenic into fine particles and the arsenic gets dissolved. If water is pumped incessantly over a long period of time, the quantity of arsenic will gradually increase.
Shallow tube wells extract water from the upper and intermediate aquifers. The intermediate aquifer is just below the 1st impervious layer. As a result Arsenic is leaching from the 1st impervious layer and remains soluble in the water of the intermediate aquifer. The oxidation theory also justified the occurrence of acid sulphate soils in Jessore, Faridpur, Khulna. As the Ganges sediments are calcareous in nature, the calcium neutralises the acid formation otherwise we might have had more acid sulphate soils. The Ganges water is itself neutral to slightly alkaline and contains a high level of dissolved oxygen (which is why it does not putrefy when kept in bottles).
But as the people are getting arsenic also from food such as rice, fish and vegetables, the problem grows ever larger. Mr. Mustak Ahmed, a former student of Soil Science at Dhaka University reported that if you irrigate land with 50 cm of water containing 35 u Arsenic/Litre, the soil will end up with an accumulation of 0.1 ppm arsenic in the soil. The Farakka barrage caused wet desertfication in Bangladesh. A study was conducted by Dr. Jabber et al. (1985 or 1986) to delineate desert-like area in Rajshahi. India has built embankments along the banks of the Ganges to canalise the flow of water with the result that, during the monsoon, India can release as much water downstream as it likes so as to ameliorate its own flood problem. India is now planning to build a dam on the Ganges at Tehri (8000-10000 ft above mean sea level), Garwal of Utter Pradesh. This project will divert more water for irrigating Basmati rice.

Although health issues relating to second-hand smoke were once greeted with skepticism, these are now standard working environments. Like the smoke-free working environment, employers today are now considering safe, fresh drinking water to be a priority area saying a corporate move to safer drinking water could provide significant improvements in absenteeism and reduce medical costs. In view of the arsenic problem, a governmental move toward safe drinking water would now be appropriate.

The West Bengal Government's investigation revealed there is a 450 km long layer of arsenic rich silt clay lying between the depths of 70 and 200 feet below the surface of the upper deltaic plain of river Bhagirathi. All these zones are located between the Ganges-Bhagirathi river and the western border of Bangladesh. The sediments on both sides of the border have the same depositional history and geological environment. The area is a part of the Ganga-Brahmaputra delta. The delta proper as well as the flanking areas forming the so-called Bengal basin is divided into six macro-process regions: laterite upland, Barind, upper delta plain of meander belt, valley margin fan, marginal plain, lower delta plain and delta front. The aquifer of the contaminated zone in West Bengal and Bangladesh are hydraulically connected. Although the arsenic poisoning of ground water in the lower Gangetic delta is posing a serious threat but in spite of arsenic-contamination of the ground water, this has not received the media attention they deserve, especially abroad. However, unless people are willing to throw their weight behind the solving of this issue by providing alternative sources of drinking water, this problem, unlike the arsenic, will become insoluble.

Acknowledgements:

1. Dr. S.S.M.A. Khorasani - Dhaka University.
2. Dr. Tom Lawand - Brace Research Institute, Canada.
3. Ms. Samira Abbasi - Environmental Engineer.
4. Dr. A. H. Khan - Dhaka University.
5. Mr. Khondker Rafiqul Islam - Maryland University, USA.
6. Dr. Fanning - Maryland University, USA.

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8. WATER POLLUTION IN THE GANGES BRAHMAPUTRA DELTA PLAIN

JAMAL ANWAR

1995 Pacific Basin Conference on Hazardous Waste, Edmonton, Canada

Abstract

The Ganges-Brahmaputra delta is the largest delta in the world and the rivers contribute one-third of the global sediment transport to the world oceans. The rivers flow through 10 per cent global population and carry untreated rural, urban, municipal, and industrial wastes to the Bay of Bengal. India ranking the tenth largest industrial country of the world but most industrial plants use outdated and polluting technologies. The river Ganges flows through more than 700 cities and about 120 million litres of waste water added daily. DDT factories, tanneries, paper and pulp mills, petrochemicals and fertiliser complexes, rubber factories and host of others use river to get rid of their waste. 70 per cenr of surface water in India is polluted. About 6,000 large and medium industries and 24,000 small industries are operating in Bangladesh discharge untreated effluents (10 to 100 times the allowable levels permissible for human health) directly to the rivers without any regard to environment. All of Bangladesh's sewage is flushed directly into Ganges and Brahmaputra Rivers. Increase chemical based agriculture and destruction of natural environments due to structural measures in this subcontinnent pose the greatest threat of surface and ground water contamination. A rapid disappearnce of forests, coastal mangrove forests and wetlands is increasingly lacking in natural purification of polluted waters. The point and non-point sources of surface water pollution are creating chemical and biological contamination, channel contamination and basin contamination and the existing management efforts are incapable to meet the problems.

The environmental policies in Bangladesh Governments plans and priorities are conspicuous by their absence and where they exist they are inadequate, outdated or unforceful. While the Government's proposed industrial pollution regulation is sensible, its implementation will require considerable technical and corruption-free management. It will take decades for controlling the proposed act. The development projects in this region benefit only richer society.

The region requires pollution prevention and conservation of natural environments, cheaper technology for effluent treatment and social change for a sustainable development. The Ganges-Brahmaputra Rivers transport annually 2.9 billion tonnes of nutrient rich sediments to the Bay of Bengal and there is no effort in the country to utilize this unique natural gift. Bangladesh urgently needs to develop improve farming techniques for traditional varieties under regulated flash of annual nutrient-rich flood waters in the agricultural land and reducing reliance on chemicals.Social changes are required in ist value-systems. If the society of North and South does not want to see, feel, and act according to global and regional reality, our blue planet will not survive.

1. INTRODUCTION

bottom ganga flowing to bangladesh The Ganges originates from the Gangotri glacier in the Himalayas at the elevation of 7,010 meter where the length of the main river is about 2,550 km, the catchment area is about 1,087,300 sq. km. and in Bangladesh lies 46, 300 sq. km. The Brahmaputra river rises south of the Lake Konggyu Tsho in Tibet (China) and has a total catchment area of 552,000 sq. km. lying in China (270,990 sq. km.), Bhutan (847,000 sq. km.), India (195,000 sq. km.) and Bangladesh (39,100 sq. km), (Fig.: 1). The Ganges-Brahmaputra- Meghna river system carries over 2.9 billion tonnes sediments (one third of global sediment transport to the world ocean, Milman et al., 1983) into the Bay of Bengal. Thousands of years of civilisation flourished along the Ganges-Brahmaputra rivers. The ancient Indians considered that the force behind flowing water was a god. Mother Ganges or "Ganga Mai" was originally a water of goddess worshipped by the non-Aryans. Darian describes :

No river has kindled Man's Imagination like the Ganges.... Since Vedic times from 1000 B. C. Indian thought has provided the elements with human counterparts. This personification, in the form or myth, allows humans some recpurse from the otherwise malevolent forces of nature. people pray not to water but to the life within the water.

The Ganges particularly Yamuna are among the most sacred rivers in India or possibly anywhere in the world. Jawahrlal Neheru wrote:

The Ganges, above all the rivers of India, has held India's heart captive and drawn uncounted millions to her banks since the dawn of history. The story of Ganges, from her source to the Sea, from old times to new, is the story of India's civilisation and culture, of the rise and fall of empires, of great proud cities, of the adventure of man....

Unfortunately the rivers of this subcontinent have become the garbage of the nations. 70 per cent of surface water in is polluted (Sibert and Dutta, 1990). The Ganges in particular is full of toxics, including decomposing bodies tossed into it along most of its length, for example at Varanasi about 10,000 half-burned bodies are pushed into the river each year, along with 60,000 carcasses of cows, dogs and buffaloes. Calcutta dumps close to 400 million tonnes of raw into Hooghly Estuary (Hinrichsen, 1990). The State of India's Environment, A Citizen's Report describes:

Out of India's 3119 cities, only 209 have partial sewage facilities and eight have full facilities, besides DDT factories, tanneries, paper and pulp mills, petrochemicals and fertiliser complexes, rubber factories and a host of other use the river to get rid of their wastes.

An Indian's daily diet contain 0.27 mg of DDT and the accumulated DDT in the body tissue of an average Indian is said to range between 12.8 and 31 parts by million which would rank among the highest in the world (Verghese, 1990). It is likely to have the same trend in Bangladesh.

All of Bangladesh's sewage and industrial wastes are flushed directly into Ganges and Brahmaputra Rivers. There are widespread fears that as the region develops in industrial infrastructure, industrial pollution will accelerate, compounding the problems posed by raw municipal wastes. Since 1982 industrial development accounts 9 per cent of GDP and the Government is planning for a rapid increase in industrial products to meet country's vast unemployment. About 900 polluting industries in Bangladesh dispose of untreated industrial wastes directly into rivers, although the effluents contain 10 to 100 times the allowable levels permissible for human health (Ministry of Environment and Forest, Govt. of Bangladesh, 1991).

2. THE STATE OF THE RIVERS

The rivers of this sub-continent originate from the Himalayan and mass wasting is very widespread constant faced in all parts of the Himalayan. Besides natural factors they are aggravated by anthropogenic factors such as:

i) loss of forest cover
ii) extension of agriculture onto steep slopes
iii) open-cast mining without environmental control
iv) roads built without regard for geological and ecological factors.

Economic development in the Himalayan region in the last few decades mainly consists in the felling of forests, the increase export of medical plants, construction of water works, exploration and mining of minerals, enhanced tourism, the introduction of commercial farming together with limited urban industrial growth in the foothills (Stone, 1993). The environmental impact due to mining in the Himalayan region (Utter Pradesh - 4819 ha, J & K State - 886 ha, West Bengal - 1147 ha) includes loss of production (forest, agriculture, pasture), loss of top soil, reduction in flow of water, lowering water tables, hazard of debris, sedimentation of streams and fire hazards etc. (Sahini, 1992).

Between 1951 and 1976 agricultural land increased by 430,000 sq. km (15 percent of land area), much of this through conversion of non-reserve forests which were originally intended to meet rural fodder, fuel and timber supply. Certain groups of plants are particularly at risk notably medical plants due to over-exploitation by the local pharmaceutical industries (Hussain, 1983).

The accessibility introduced by new roads accelerated economic transformation and population growth in a way which had little regard or concern for ecological fragility of the Himalayan region. Forest became denuded, roads and mines created enormous land instabilities, the intensification of agriculture led to soil degradation and erosion, pastures were damaged by over-exploitation while natural courses of rivers were dammed and all these factors together created a massive sedimentation problems. Consequently severe flooding and subsequently followed by drought. experiences India, Nepal and Bangladesh almost every year .

The Ganges-Brahmputra delta, the largest delta in the world suffers water pollution due to several factors such as dense population, no sewerage, removal of natural waters, decreasing dilution, contaminated ground water, river used for waste disposal, no treatment of effluents and increased chemical based agriculture. The categories of wastes create water pollution are as follows:

Liquid Inorganic wastes:

Most of the inorganic liquid wastes come from industry, and their dilution in large river waters renders them harmless. Some inorganic toxic wastes can become concentrated up the food chain to fish. Many of the pollution incidents which have been resulted in many parts of the world in largest number of deaths and serious injuries from water pollution have been arisen from human ingestion of fish, or crops contaminated with heavy metals or other inorganic compounds.

Liquid Organic Wastes:

Wastes when disposed of in water, bacteria and other micro-organisms combine with oxygen dissolved in water to break them down, can be termed as "oxygen demanding" wastes. Liquid organic wastes include sewage, many wastes from industries (especially industries producing agricultural and tannery products) and run-off from rains, floods and storms which picks up organic wastes from land, before flowing into streams, rivers, lakes or seas. As concentration of dissolved oxygen decreases, so fish and aquatic plant life suffer or die. According to Department of Environment, Government of Bangladesh (1988), Karnaphuli River shows following intolerable BOD values: at Kalurghat (tannery and food processing industrial area) 800 - 12,000 ppm, at Chandragahna (paper mill) 60 ppm. Industrial wastes also creates a very high chemical oxygen demand (COD) ranges between 75-600 mg/l. Besides, Buriganga River near Dhaka shows BOD between 5-75 mg/l. A wide spread of fish deaths have occurred in these areas, and thousands of fishermen have lost their jobs. In Damodar river, near Calcutta BOD level rises upto 30 mg/l (Rao, et al., 1991).

Waterborne or related pathogens:

Many pathogens (disease causing agents including bacteria, viruses and worms) are spread in water - either through human ingestion of contaminated water or because water provides the habitat for intermediate hosts. Outbreak of floods in Bangladesh causes disease epidemics of dysentery and other waterborne and water-washed diseases, as floods contaminate all available water supplies.

The surface water contamination poses greatest threat from Industrial, Municipal and Urban Wastes and Agriculture.

2.1 INDUSTRIAL, MUNICIPAL AND URBAN WASTES :

In 1987 India exported about US $ 500 million leather. About 250 different toxic chemicals and heavy metals like cadmium, chromium, arsenic, zinc etc. are used by the leather industry and these wastes are disposed of in rivers (Dittfurth and Röhring, 1987).There are about 2,000 tanneries in India with an annual processing capacity of 500,00 tonnes of hide and skin. Besides other toxic chemicals, annually 25,000 tonnes of chromium salt is used and out of this 10,000 tonnes of chromium salt in the form of Basic Chromium Sulphate is discharged into waste water streams causing environmental pollution (Schaapman, Rajmani and Pelckmans, 1990).

The Ganges and her tributaries flow through main industrial sites, cities and agricultural lands of India and enter the deltaic plain of Bangladesh (Fig. 1). The River Ganges flows through 700 cities in India, and about 120 million litres of waste waters from the industries and municipalities are added daily. The Ganges at Calcutta obtains daily 252 million gallons of liquid wastes, and of which 77 million gallons is industrial wastes (Dept. of Environment, Govt. of Bangladesh, 1988). The State India's Environment, a Citizen's Report points out that of India's 3119 cities, only 209 have partial sewage and sewage facilities and eight have full facilities. The report further adds:

DDT factories, tanneries, paper and pulp mills, petrochemical and fertiliser complexes, rubber factories and a host of others use the river to get rid of their wastes from more than 150 major factories around Calcutta ... raw sewage pours into the river continuously from 361 outfalls.

The National Commission of Urbanisation in India reports (August, 1985):

A major feature of our urban scene is misery and serious health hazards caused by lack of water supply and sanitation. Almost all our urban centres, even those which at one time had reasonably adequate water supply, are now suffering from crippling shortage.

River Yamuna that flows to the Ganges consider to be highly polluted. Verghese (1990) reports:
Civic and industrial pollution pose a threat to fish and other aquatic life. Tannery discharges into the Ganges at Kanpur have resulted in toxicity levels that are inimical to fish. Fishermen report virtual absence of fish in certain reaches. Effluents draining into the Yamuna via the Hindon from Ghaziabad have from time to time resulted in mass fish-kills at Okhla in Delhi. Pollution destroys fish directly by poisoning and reducing the oxygen content, killing fish food and affecting spawning grounds. Some species of air-breathing fish might survive in polluted waters but bottom dwellers find the water devoid of plankton and benthos. Persistent pollution can cause mutation and bring about genetic changes. Arsenic, mercury, chromium and other heavy metals pollutants are dangerous as they tend to accumulate in fish tissues and can enter the human system through food chain........Bandel to Budge on the Hoogly at Calcutta is yet another badly polluted stretch.

The present economic development increasingly widens the gap between the poor and the rich. The limited agricultural land does not allow any further expansion along with the fast expanding population of working age. In view of this problem the Government of Bangladesh is planning for a rapid increase in industry, commerce and services (55.7 per cent of GDP). At present industrial manufacturing accounts for about 10 per cent of GDP in Bangladesh and 10 per cent of total employment, and contributes about three-quarters of total merchandise exports. The earliest industries in Bangladesh were based primarily on agricultural products like jute, sugarcane, tobacco, forest raw materials, and hides and skins. During the mid-sixties a modern industrial base emerged as heavy industries like steel, machine tools, electric machines, diesel plants, refineries, pharmaceutical plants and other chemical industries were set up. From 1985 to 1990 the industrial sector achieved an average annual rate of growth of 4.02 per cent. In recent years, the major source of industrial growth has been in textiles, with ready-made garment manufacture expanding from insignificance in the 1970s to the leading export earner today. Leather tanning and brackish water shrimp farming have also expanded rapidly and are expected to grow further.
The industrial areas in Bangladesh are situated in the midst of densely populated regions. There are many hazardous and potentially dangerous polluting industries situated in the cities of Bangladesh. In Dhaka at Tejgaon area, food processing industries are situated along with chemical and heavy metal processing industries. In Tongi a pharmaceutical industry is situated near a pesticide producing industry. Tannery industries of Hazaribagh also situated in a heavily populated residential area. These examples are repeated in the cities of Chittagong, Khulna and other smaller cities of Bangladesh. The Government of Bangladesh has not shown much interest in environmental impact created by the industries, whereas government's concern to create jobs usually meant that when a new factory is proposed - by local, national or international business or agency - little attention is given to the likely environmental impacts.

Surface water pollution in Bangladesh occurs mainly by human sewage coupled with municipal garbage and industrial effluents. Industrial discharges along with municipal and urban wastes are creating special problems that completely destroy the microbial-based systems of decomposition.

About 6,000 large and medium industries and 24,000 small industries are operating in Bangladesh which discharge effluents directly to the rivers or nearby canal or waterbed without any regard to environment. According to the Department of Environment, Government of Bangladesh about 903 polluting industries such as 176 tanneries, 5 paper and pulp plants, 16 sugar mills, 3 distilleries, 57 iron and steel mills, 298 textile units, 5 fertiliser plants, 23 insecticide industries, 92 jute industries, 3 cement industries, 34 rubber and plastic industries and 166 Pharmaceutical industries are the most polluted industries of Bangladesh. Under the Environmental Pollution Control Ordinance of 1977 are not required to take clearance from the Government for their project plants, permits or consent for discharge of pollutants. Other sources of water pollution are disposal of hazardous wastes from boats and ships, and dumping of scrap from ship breaking yeards.

So far there is no monitoring facilities for controlling or inventorying on water qualities of rivers of Bangladesh. The status of some polluting rivers are as follows (Figs.: 1 and 2):

2. 1. 1. Buriganga River

All industrial, municipal (700-1100 tonnes daily) and urban wastes of Dhaka city ( population 1989 about 6.5 million and expected to grow in year 2000 to 11.1 million) are flushed into the Buriganga River. It is estimated that total organic waste load discharged into the river will be around 250 metric tonnes per day (Reazuddin, 1994).

The Department of Environment, Dhaka Division has selected different sampling locations. The choice of DoE's sampling station in Buriganga is based mainly on the location along the river banks. The selected locations are Hazaribagh, Chandnighat and Pagla where the major pollution sources from tanneries, city sewage and sewage treatment plant respectively

Water chemistry

The results indicate that Buriganga river is one of the major polluted rivers in the country, with Hazaribagh station being the most polluting station. Dissolved Oxygen (DO) at Hazaribagh can be as low as 2 mg/L during January to May. Total solid and chlorides are also sharply higher here. Hazaribagh is estimated to discharge water around 16,000 m3/day generating about 18 MT of Biological Oxygen Demand (BOD) per day into Buriganga. In addition, Hazaribagh main effluent drain discharges waste water from tanneries which contains high levels of Chemical Oxygen Demand (COD) in the order of 1100 mg/L and chromium at about 11.5 mg/L. Seasonal variation of DO and BOD are also observed. During flush season, DO increases to the level of 4-5 mg/L and BOD reduces to the level of 3-4 mg/L which is just critical level for recreational and domestic use

The situation of Chandighat, which is in the middle of the river, is as bad as Hazaribagh excepting in terms of chemical Oxygen Demand (COD) load. In Pagla, though there is discharge from Pagla sewage Treatment plant, the result indicates a higher level of oxygen compared to Hazaribagh and Chandighat stations. In addition, data on Total Solids and Turbidity indicate that the river is highly turbid and waded with solids residues almost throughout the river. The reasons for high pollution and oxygen for most of the length of the river may be attributed to the discharge from Rayer Bazar sluice gate, Dolai Khal, Pagla Sewage Treatment Plant, hanging latrines.

Sources of pollution load from industries include Hazaribagh tanneries, Tejgaon industries and others which discharge waste water around 15,800, 3,500 and 2,700 m3/day respectively and generate around 17,000, 1,850 and 1385 BOD 5/day respectively (BCAS, 1998)..

The following description of Hazaribagh leather industry explains the present status of industrial pollution in Bangladesh:

Hazaribagh Leather Industry

The annual supply of hides and skins in Bangladesh is estimated to be about 13.95 million square meters. Only 15-18 per cent of the total supply is needed to meet the domestic requirements and the rest about 11.81 million square meters remains surplus for export.
The small leather industry of Indian-subcontinent developed Indian vegetable tanned crust over a hundred years ago to preserve the hide in the safest way to suit Indian conditions. The development of leather processing industry was started in Bangladesh in the late 1940s. Until mid 1960s, the leather was dominated by vegetable tannage for supply to W. Pakistan, Iran and Turkey. Manufacture of wet blue, the chrome tanned semiprocessed leather started featuring in 1965. There was a rapid growth of tanning industry in Bangladesh during 1970s and by the end of 70s. Until 1980-81, the export from leather sector was almost 100% in the form of wet blue, the chrome tanned semi-processed leather (Table: 1).
In 1977 the Government of Bangladesh imposed export duty on wet blue leather so that the industry produces crust and finished leather. With the ban on wet blue export from July, 1990, the leather industry of Bangladesh is entering into second phase of its development, the conversion of finished leather into further value added leather products to earn more foreign exchange. Promotion and Protection Act of 1980 provides protection of foreign investment in Bangladesh. There are German, Italian etc. joint venture plants are established in Bangladesh (M/S H. H. leather Industries Ltd, M/S BATA, M/S Lexco Ltd, M/S Apex Tannery Ltd).
The operation in tanning which give rise effluents may be categorised into pre-tanning and post-tanning processes. Pre-tanning is employed mainly for the removal of impurities from the raw materials. These consist largely of protein (blood, hair, etc.) and the process chemicals employed include salts, lime and sulphides. The tanning processes themselves are used to alter the characteristics of skin or hide and their effluents contain chromium and vegetable or synthetic tanning. Post-tanning process include coloration and produce effluents typical of these addition processes; that is, containing residues of dyestuffs or pigments and larger quantities of auxiliary chemicals. The process chemicals employed are a variety of inorganic and organic materials, affecting total solids, pH, COD and of particular importance are the applicable quantities of sulphide and of heavy metals. Hazardous chemicals for leather and dyes treatments are Ammonium Bicarbonate, Chromic Acetate, Ethylene Glycol Monoethyl Ether, Methylamine, o-Nitrophenol, Toulene Diamine, 2,4,5-Trichlorphenol, Zinc Hydrosulfite, Zinc Sulfate, tert-Butylamine, Cadmium Nitrate, Cadmium (II) Acetate, Copper(2)Nitrate, 1,4-1,8 Dichloronaphthalene, Nickel Sulphate, o-Xylene, Zinc Nitrate etc.170 tanneries of Hazaribagh generates waste water about 5,000 litres/100 kg of hides and skins. BKH Consulting Engineers in 1986 reported the following characteristics of the effluents:

Parameters range of variation

pH	4-10
Total alkalinity as CaC03	185-6475 mg/l
Electrical conductivity	670-5300 (Micro-mhos/cms)
Chloride	175-18000< mg/l
Chromium	3-28000 mg/l
COD	120-9600 mg/l
Ammonia nitrogen	12-1970 mgl

Tubewells for drinking water adjacent to the down-gradient from the Hazaribagh industrial area is highly polluted.
For example Chromic Acetate shows the following characteristics (Sax, 1986):

Potential of Accumulation	Positive
Food Chain Contamination Potential	Positive, can be concentrated in food chain
Etiologic Potential	Chrome ulcer
Carciniogenecity	Potential, higher occurrence of lung cancer
Acute Hazard Level	Extremely toxic if ingested or inhaled. Corrosive to living tissue
Degree of Hazard to Public Health	Highly toxic material via ingestion or inhalation. Corrosive to skin and mumem; potential carcinogenic

At present in Bangladesh the tanner's basic wet process technique is to treat the stock with increasing concentrations of process chemicals using water as the carrier. In order to ensure full penetration of the thickest hide or skin in the batch, these concentrations are in excess of what is needed and the unabsorbed chemicals are discharged in the effluent, where they are a waste and cause expensive treatment problems.

While the Chemical companies in the Federal Republic of Germany, the United States, the United Kingdom, Switzerland, Spain and Italy provide short term training on the application of their chemicals, Whereas they do not provide any assistance how to treat toxic effluents that increasingly contaminate surface and ground water. Consultants provide technological transfer and management either on arm's length fee paying basis on assignment or financed by the World Bank, UNIDO, ITC or other United Agencies.

The small cottage tanners of Hazaribagh producing sandal leather out of cow heads are probably the only tanning group in the world using waste tanning liquor from the modern tanners as their process liquor. But after using these waste are eventually discharged, as are all other tannery discharges in the Hazaribagh tanning effluents into the streets, gutters and sewers which ultimately enter surface and ground water.

According to Dittfurth and Röhring (1987) about 250 different toxic chemicals and heavy metals like cadmium, chromium, arsenic, zinc etc. are used by the leather industry. When the local industry was basically a vegetable tanning complex, this effluent might have been high in BOD and unpleasant but particularly dangerous.

There is, in addition, an extremely hazardous air pollution occur in Hazaribagh which is not known in any other places of the world. The rest treated hides and skins are cooked in open air to obtain glue for the local market. They burn treated leather pieces instead of coal or wood as it is cheaper. The smog and the smell like a witch cooking pot and it is beyond author's capability to narrate.

The most hazard occurs when the poorer group uses poisonous treated leather pieces as an alternative fuel to cook regular meals. No body knows how much harm and potential carcinogen diseases will occur to the slum inhabitants. There is no warning from the Government or aid giving agencies or their representatives. This is the vicious circle that the poorest groups are the worst victims of the foreign currency earning schemes.

2. 1. 2. Sitalakhya River

Besides wastes from Dhaka urban population the river receives untreated industrial wastes from urea fertiliser plants, textile mills and other industries. The principal polluting agent in the region is the Urea Fertiliser Factory of Ghorasal and the concentration of ammonia dissolved in water has increased over time causing fish-kills.

2. 1. 3. Balu River

The river near Tongi (15 miles north of Dhaka) receives untreated effluents from industries such as textiles, lead batteries, pulp and paper, pharmaceuticals, paints, detergents, iron and steel, rubber etc.

2. 1. 4. Bhairab/Rupsa Rivers

The principal industries of Khulna (south-east of Bangladesh) are jute mills, oil mills, newsprint mills, cable, shipyards, tobacco, match factories, hardboard and others dispose molasses, starch, oil, sodium-sulphide, ethane, lissapol, sodaash, dye, sulphuric acid, salicylic acid, lime, ammonium sulphide, and chrome etc. Afew study at Bhairab River shows a very alarming water quality data (Nov.-April 1988-89) - conductivity 390-9500 Micro-mhos/cms, total solid 260-3500 mg/l, TDS 260-3200 mg/l. The pollution aspects of Bhairab and Rupsa Rivers is very critical - the Rupsa River does not receive a continuous flow of fresh water from the parent river, on the other hand, the Bhairab River, being subject to tides, has marked backwater effects which reduce the purification capacity of the river.

2. 1. 5. Karnaphuli River

The polluting industries of Chittagong (south-east of Bangladesh) such as 19 tanneries, 26 textile mills, 1 oil refinery, 1 TSP plant, 1 DDT plant, 2 chemical complexes, 5 fish processing units, 1 urea fertiliser factory, 1 asphalt bitumen plant, 1 steel mill, 1 paper mill (solid waste disposal hourly 1450 m³), 1 rayon mill complex, 2 cement factories, 2 pesticide manufacturing plants, 4 paint and dye manufacturing plants, several soap and detergent factories and a number of light industrial units directly discharge untreated toxic effluent into Karnaphuli river. From the survey of effluents from different industries , it has been found that the discharge is generally compose of organic and inorganic wastes.

The organic waster are the effluents from the tanneries, fish processing units, degradable wood chips, pulps and untreated municipal and sewage (about 40,000 kg BOD daily) etc. The inorganic waster are chemicals used by the industries such as various acids, bleaching powder, lissapol, hydrogenperoxide, alkali, salts, lime, dyes, pigments, aluminium-sulphate and heavy metals etc.

The DDT factory and fertiliser factory disposing of DDT, toxic chemicals and heavy metals to the Karnaphuli River and ultimately to the Bay of Bengal ( Table: 2 and 3). The tables show about 220 ppm of chromium, 0.3-2.9 of cadmium, 0.05-0.27 ppm of mercury, 0.5-21.8 ppm of lead entering river and sea water much higher than allowable limits. and extremely alarmingly to aquatic flora and fauna and through food chains to human beings. It may be mentioned that Bangladesh obtain table salt from solar drying of sea water and consequently increase pollution of sea water shall create a serious national health hazard situation.

About 20,000 fishermen became jobless at Rangonia, Boalkhali and Anwara Upazila due to water pollution (Dept. of Environment, 1988). The estimate of crude oil spillage at Chittagong is about 6,000 metric tonnes per year, while about 240,000 gallons per year of bilge water is also dumped (Ministry of Environment, 1992). Polycyclic aromatic hydrocarbons known to be carcinogenic enter the river water and also the Bay of Bengal. But no specific study or quantitative analysis of the run-off, discharge amount or residue level has so far been analysed.

3. POLLUTION FROM AGRICULTURE

irri India currently uses about 5 million tonnes of fertiliser, around 12 000 tonnes of pesticides and manufactures 55 varieties of pesticide, of which DDT, BHC and malathion account for half of the output (Verghese, 1990). In Bangladesh during 1979-80 total use of pesticides was nearly 2,3047 tonnes, whereas the use rose during 1984-85 to nearly 4,000 tonnes, during 1989-90 to more than 5,000 tonnes and during 1992-93 about 7,200 tonnes. Indiscriminate and excessive use of pesticides in increasing amount are posing greatest threat to surface water pollution in the Ganges-Brahmaputra delta plain. DDT and other highly toxic pesticides (Dirty Dozen) are indiscriminately used by the farming community.

In Bangladesh total production of rice (Aus, Aman, and Boro) and wheat increased from 9.9 million tonnes in 1972/73 to 19.1 million tonnes in 1990/91. This has been achieved through extensive cultivation of HYVs (High Yield Varieties) of rice and wheat with extensive use of fertilisers, pesticides and irrigation. The total area under irrigation has increased from 1.2 million hectares in 1973 to 3.1 million hectares in 1989 (Ministry Environment and Forest, Govt. of Bangladesh, 1991).

Year round transplanted rice cultivation keeps the land water-logged continuously for many years. Fertilisers and some pesticides are leaching through the soil into shallow groundwater's. There is no available systematic studies on nitrate contamination in Bangladesh. A rapid increase in nitrate content is expected in the rural areas of Bangladesh. About 20 percent of the rural population obtain drinking water from surface sources, whereas the rest rely on shallow tube-wells (30-60 meter depth). High mortality death rate of children under the age of five indicating increasing pollutants in drinking waters. Maintaining high quality groundwater will require practical approaches to prevent contamination, because of the increasingly vast areas involved.

The traditional varieties of rice such as Aman, Boro, Aus etc. are replaced in many areas by HYV. At present the farmers complains that a declining yield of HYV rice despite increasing use of chemical fertilisers and pesticides. Year round mono-cropping resulted in Bangladesh depletion of soil nutrients, formation of toxic compounds in soil and about 1.74 million ha land is deficient in essential nutrients (sulphur, zinc). This has caused 10 per cent crop reduction, 17 per cent for rice crop (Ministry of Environment and Forest, 1991).

The Government and many Organisation in Bangladesh reported that the deterioration in soil fertility is attributed to continuous monocropping of rice, particularly HYV rice. The daily "Bhorer Kagag" reports on November 11, 1994 almost all HYV rice fields in the southern districts of Bangladesh are severely destroyed by the insects, whereas 16 districts of the northern part of Bangladesh seriously lacking of essential trace minerals (crop production will reduce to 40-50 % within the next three to four years).

After the construction embankments, where the HYV 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 nutrient poor soil. The loss of vital nutrients like illite, montmorillonite clay minerals, silt, organic matters (nitrogen supplying algae) are compensated by chemical fertilisers. The environmental aspects of surface water development projects have been neglected by the planners and engineers. In the planning of projects farmers requirements and knowledge are not considered. Mainly engineers' decisions and designs are imposed on them (Khan,1987).

For example under the Ganges-Kobadak Irrigation Project construction of flood embankments produced flowing rivers like Kumar, Kaliganga and Dakua to dead rivers which created a serious ecological disaster. Another example of ecological disaster is Horai River Sub-Project where in February 1989 the inlet of the Horai River at the Padma (Ganges) end closed down which resulted 20 beels (wetlands) of 9,000 acres dried up. Besides the loss of wetland prevented the annual recruitment of fish prawn and nutrient rich water from the Padma (Ganges) river.

If the current trend continues, in twenty years about 2 million ha flood plains would have been permanently removed due to flood control and drainage development (Ministry of Environment and Forest, 1991). After China and India Bangladesh is the third largest country in the world in inland fisheries. But at present the average yields for inland fishery are low and declining by about 2.7 per cent a year. However, this decline have been offset by increased inland culture fisheries by the richer group of rural population.

But the poorer group of the rural population (more than 80 per cent) who used to catch fish from the floodplains as the only source of animal protein is interrupted from this source due to structural measures and increasing surface water pollution. In 1960 average caloric intake in Bangladesh was more than 2,300 which reduced to 1,920 in year 1990. A large number of children in poor families become blind every year because of nonavaility of proper diet.

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.

There were about 30,000 rice varieties cultivated by farmers in the Indian-Subcontinent and at present only 15 varieties comprise 75 percent of rice cultivation. Monoculture creates a market for crop chemicals. More advanced varieties of seed will lead to more toxic chemicals, greater risk for farmers, achieves only more environmental damage. Pat Mooney and Cary Fowler, the Noble Prize winners of 1985, described it as "genetic erosion", most prominent of all is the environmental erosion.

4. DISCUSSION: MANAGEMENT - BEYOND CONTROL

About 10 per cent of global population is living in the Ganges-Brahmaputra delta and the population is increasing more than 2.6 per cent annually and the it will double in 27 years. In view of this the governments of this region have increased the production of chemical based agriculture (Monoculture) and rapid industrialisation programme without considering environmental impacts. The non-point sources of water pollution have increased tremendously and even if all the major industries and urban and municipal sewage obtain cleaning systems water quality will deteriorate due to non-point sources.

India ranking among the ten most industrialised nation with GDP about 5-6 per cent yearly has brought unwanted and unanticipated consequences, including unplanned urbanisation, pollution and risk of accident. Most industrial plants use outdated, polluting technologies and makeshift facilities (Centre for Environment Education, India, 1992). It is praiseworthy that in 1985 India lauchned Ganga Action Plan when Prime Minister of India declared "we will restore the pristine purity of Ganga". The plan intends:

to intercept and treat raw sewage flowing directly into the river;
to ensure and enforce proper effluent treatment;
to promote and assist programmes for supply of protected drinking water, construction of latrines, and electric crematoria etc

The Ganga Action Plan is a 532 cores Rupees project believes an expert of the Thames Water International that some of the quality norm set are questionable or may be unattainable (Verghese, 1990). The management problems are:

over 900 million litres of sewage is dumped into the Ganges daily;

installation of effluent treatment plants are expensive and premature closure can cost can displace workers . For example 2,500 tanneries discharge daily 80,000 cubic meter of waste. More than 90 per cent of tanneries are small and medium scale and are scatteredly situated which neither can set up individual effluent treat ment plants nor be included in a common effluent treatment plants (Rajamani, 1993). Besides most of the industries will not be profitable after constructing modern effluent treatment plants;

rapidly increasing amount of fertiliser, pesticides runoff from agriculture increasingly deteriorating surface and ground water quality. Non-point sources also include infiltration from the surface into vulnerable aquifers - seepage from underground and surface mining operations - and wet and dry deposition in lakes and aquifers. India's coal has a very high ash content (35-40 %), the disposal of which is a major problem (Centre for Environment, India, 1992).

The Ganges transports 83 million tonnes of dissolved solid along with 2.5 per cent of global flux of sodium to the oceans, whereas the Brahmaputra transports 35 million tonnes of dissolved solid to the Bay of Bengal (National Environmental Engineering Research Institute, India, 1987). 70 per cent of surface waters in India is seriously polluted (Sibert and Dutta, 1990 and Centre for Environment Education, India, 1992).

The major rivers of India along with polluted load flow deltaic plain of Bangladesh and finally to the Bay of Bengal. In Bangladesh the combined flow of the Ganges and Brahmputra typically increasing from less than 10,000 cubic meter per second early in the year (dry season) to a peak of 80,000 to 140,000 cubic meter per second in late August or early September. Shortage of water in dry season is exacerbated by the diversion of Ganges at the Farakka Barrage, India. During dry period (November to April) surface water pollution increases especially down streams of Industries and cities.

dirty water UNICEF (1986) reports that in 1983 there were over 57 million episodes of diarrhoea among children under five causing an estimated 200,000 child deaths. The National Cancer Society of Bangladesh on Nover 4, 1994 reports that about 800,000 persons are at present suffering from cancer and about 150,000 deaths annually occur in the country (Daily Sangbad, November 4, 1994). There is no study that correlates diseases to environmental impacts. But there is no doubt that most of the diseases are related with surface water pollution, as in Bangladesh vast majority of the rural population uses ponds and other surface sources and only 2-4 per cent of the population has a sanitary latrine.

The present liberalised industrial policy in Bangladesh ignores environmental protection - private entrepreneurs do not require permission from any quarter. Banks in general accord permission to the project, if it is financial viable. With the increase of unplanned and socially and environmentally degraded industries Bangladesh poses a new challenge. Pollution and human-induced hazards are particularly serious in the developing nations, because industrial production is heavily and scatteredly concentrated in city regions or 'core regions' within each nation.

The deterioration of surface water quality is a serious problem in this subcontinent and it will grow further if the present policy of industrialisation and agricultural practice continues. A recent study which covers most of the subcontinent shows that between 1890 and 1970, more than 30 million hectares of land were transformed from forest and grassland into areas of crop production and settlement (Tucker, 1988).

Most of Bangladesh was originally forested, with coastal mangroves backed by swamp forests and a broad plain of tropical moist deciduous forests. Remnants of these forests, the Sunderbans, still the largest mangrove forest of the world is threatened (ODA inventory in 1983 reveals that Gewa and Sundri declined to 40-45 % since 1958-59) due to structural measures in the Ganges River and over-exploitation. Almost half of Bangladesh is wetland but the size of wetland is dramatically decreasing year by year. For example Chalan Beel (wetland) considered to be the largest wetland in Bangladesh, now covers only a quarter of 100,00 hectares that it covered 150 years ago. If the current trend continues, in twenty years 2 million ha of flood plain will be permanently removed (Ministry of Environment, 1991).

shrimp-farm Shrimp farming in Bangladesh rank third in earning foreign exchange (1983 production 2,200 tonnes, 1986 production 12,878 tonnes) contributed 10.94 % of total export earnings in 1988-89. This increase production accompanied by the destruction mangrove forests in the coastal region of Bangladesh (Anwar, 1993). In December 1994 the daily newspapers of Bangladesh reported a massive shrimp-kill in the coastal region due to unknown virus infection. Besides clearing mangrove forests and destroying aquatic larvae of coastal region, these shrimp farms threw about 23,000 metric tonnes of shrimp heads into the nearby waters every year without any regard for the decomposition, increase in BOD content, killing aquatic habitat and degrading drinking water quality.

wetland - sunderbans Apart from many other beneficial effects of forest and wetland, they improve water quality by toxic substances removal, conversion of inorganic material to organic material, metabolism of phosphorous, nitrogen and other nutrients, suspended solid removal and removal of pathogen etc. Destruction of natural water purification systems throughout the Ganges-Brahmaputra River system increasingly deteriorating surface and ultimately ground water of this region.

The point and non-point sources of surface water pollution are creating chemical and biological contamination, channel contamination and basin contamination and the existing management efforts are incapable to meet the problems. CIDA (1988) describes that environmental policies in Bangladesh Governments plans and priorities are conspicuous by their absence and where they exist they are inadequate, outdated or unforceful. While the Government's proposed industrial pollution regulation is sensible, is implementation will require considerable technical and corruption-free management's. It will take decades for controlling the proposed act. The region requires:

pollution prevention and conservation of natural environments,
cheaper technology for effluent treatment and
social change for a sustainable development.

Pollution Prevention and Conservation of Natural Environments

While developing countries are rapidly increasing the use of chemical fertilisers and pesticides, in developed countries agricultural issue moving higher on the public's agenda is the use, and over-use, of pesticides and fertilisers. For example, the National Environmental Policy of Plan in the Netherlands sets an overall goal to reduce the use of fertilisers and pesticides - by the end of this decade the use of pesticides should be cut in half. A 1987 law in Denmark gives farmers financial support to develop or convert to organic farming. Whereas in Bangladesh structural measures to grow HYV (High Yield Varieties) of crops prevent nutrient rich flood-water to enter the fields, replaced by increasing use of chemical fertilisers and pesticides. It may be mentioned that a bumper crop was recorded in Bangladesh after each major flood, when flood-water over-topped the embankments. The Ganges-Brahmaputra Rivers transport annually 2.9 billion tonnes (one third of global sediment transport) of nutrient rich sediments to the Bay of Bengal and there is no effort in the country to utilise this unique natural gift. Bangladesh urgently needs to develop improve farming techniques for traditional varieties under regulated flash of annual nutrient-rich flood waters in the agricultural land and reducing reliance on chemicals (Anwar, 1993).

Recently Bangladesh School Text Book Board introduced environmental studies in the secondary schools, but the books are the older version of the geography curriculum. It is reported that many hazardous pesticides are used for the conservation of food, medicinal treatments etc. (Anwar, 1993). Bangladesh requires an education system that is understandable to rural population., that includes:

restore traditional heritage for the conservation of natural resources<
environmental consciousness through unconventional methods
effective citizen participation in decision making
inclusion of environmental requirements at the earliest stage of decision rather than focusing on end-pipe solutions

Cheaper Effluent Treatment Technology:

Some studies report that most of the industries will not be profitable after installing modern effluent treatment plants. The conventional physical, chemical and biological treatment methods are very expensive and Bangladesh with is present resources can hardly afford such technology.

Several studies on wastewater effluents (secondary sewage, drainage wastewater, livestock waste, industrial wastes etc.) have been investigated. Dymond in 1948 first suggested the possibility of using waterhyacinth for the removal of nutrients from wastewater effluents. Experimental studies show a high rate of absorption of several heavy metals from paper mill effluents, tannery wastes and fertiliser factory waste. Field studies in Mississippi report that waterhyacinth reduces suspended solids, nitrogen, phosphorous, faecal colioform (the presence of colioform organisms is regarded as evidence of faecal contamination since these organisms have their origin in the intensial tract of humans and other warm-blooded animals), and (BOD) Biological Oxygen Demand (McDonland et al., 1980). Dissolved oxygen perhaps the most commonly employed parameter of water quality, whereas with the increase with biological oxygen demand (BOD) due to increase in organic matter in water may lead to a low level of dissolved oxygen. A high BOD adversely affects fish and other aquatic life. Mosse and Chagas (1984) also found about 83.4% reduction in total coliforms and 89.6% reduction in fecal coliforms from sewage effluents passing through waterhyacinth ponds in Brazil.

Most studies suggest that a simple passage of wastewater through a waterhyacinth pond improves water quality. The mechanisms involve in wastewater purification using waterhyacinth are similar to conventional treatment facilities. The waterhyacinth-covered wastewater receiving ponds represent a unique environment which is also stable if the water inflows and organic loading are steady. Every system of wastewater treatment units requires specific design and operation programme for maximum efficiency.

The recent scientific studies on waterhyacinth advocate that instead of wasting valuable resources on control efforts, the weed should be turned an asset in the developing countries as it can combat water pollution. In Bangladesh conventional treatment of wastewater is not available and beyond economic means. As an inexpensive and affordable method the waterhyacinth can be used to reduce or eliminate suspended solids both organic and inorganic, nutrients, heavy metals, pesticides and organic compounds. The industries of industrial countries are interested to transfer expensive and ever dependable technology to the developing countries. On the other hand interested groups in the developing countries can not earn enough from such projects.

Social Change

More than 10 per cent of world's population lives in the Ganges-Brahmaputra delta plain and if an average person in the South were to consume as much as an average person in a developed country, the environmental crisis would be unimaginable. The developing countries have so far followed strategies that are modelled after the experience of industrialisation of the developed societies. The developing countries fear that the concern for the environment would delay their material and social progress.

However, it is now considered that the natural environment will soon be destroyed by biochemical pollution, if we do not change our present methods of producing goods. In developing countries the pollution of a river and the killing of its fish may often lead to famine, whereas the extreme pollution of the Rhine or the Great Lakes would not have a similar consequence for the neighbourhood population. The development projects in Bangladesh benefit richer society . The International Assistance Programme of the Government of the Netherlands comments on projects in Bangladesh (1978):

A concentration on economic growth only benefited small groups in these societies, such as landlords, owners, managers in modernised industry and trade, and professional people and high officials in private and government circles. The contention that benefits of such a policy would automatically trickle down to large majorities proved to be untenable. On the contrary, it became clear that such policies widened still further the extremely large differences in the levels of living.

The existing projects mainly concern for the betterment of a privileged section of the population, whereas the poor continue to be the enemy, misunderstood and blamed for circumstances beyond their control. Our cultural patterns have been disrupted and our societies have become unstable. The economic situation and the policy and development system of the country are responsible for the threating environmental situation.

The suffering of the poor in Bangladesh continued to imposed by global capital, which insists on taking wealth out of our country to pay interest on debts, instead of allowing the amount spent on poverty-focused projects. In 1989 developing countries received $ 92 billion in official development assistance; they paid out $ 142 billion servicing their debts, which totalled $ 1,165 billion at the end of that year. In other words, the developing countries gave to the First $ 50 billion more than it received (Strake, 1990). Export prices of industrial countries reflect the costs of environmental damage and of controlling that damage, where as in the developing countries costs borne in the form of damage costs to human health, property, and ecosystem. There are many toxic chemicals that are banned in the developed countries, but these are allowed to export to the developing countries. The poor farmers of this subcontinent use many no-name varieties of toxic pesticides as they are cheaper.

Since twenty years Bangladesh has received about 22 billion US dollars, where 75 per cent of the amount immediately returned to the aid giving countries as expert fees and equipment purchase. Prof. Yunus, founder of Grammen Bank, comments that the situation of the poor has not all improved, where as the projects kept poverty to continue. Since independence aid giving organisations and NGOs are working to eliminate poverty in the country. When they initiated the programme the landless peasants were 37 per cent and now according to a Government report it is 58 per cent. Whereas an official source reports uneducated persons are increasing to 5,000 each day . It shows clearly the result of their works.. Prof. Yunus comments, Government programme to educate every one in Bangladesh is targeted to achieve in year 2,000, but I think to reach year 2000, it will require us 5,000 years.

In spite of billion dollars of investment by the WMF and the World Bank, the lives of fifth of the world's people are gradually worsening. The reasons of our poverty are not corruption, superstition and ignorance, but the main reasons derive from the determination of the developed countries to pursue ever-rising living standards and from the logic of the global economic system that provides them with their affluence. First World's superior effective demand enables them to secure many of the resources produced in the developing countries and to ensure that the industries built their are the industries that will produce the things that First World want, rather than things that will produce things we need, and in many cases a new market is produced which has any demand or need i

SOS-arsenic.net

ARTICLES

1. Arsenic: Growing menace

2. Ravages of arsenic poisoning

3. Arsenic Threat

4. A market basket survey of inorganic arsenic in food

5. Hydrogeological investigation of ground water arsenic contamination in south Calcutta

6. SEARCHING FOR SOLUTIONS
by Sylvia Mortoza

6. SEARCHING FOR SOLUTIONS
by Sylvia Mortoza

7. ARSENIC REVISITED
by Sylvia Mortoza

8. WATER POLLUTION IN THE GANGES BRAHMAPUTRA DELTA PLAIN

3. POLLUTION FROM AGRICULTURE

4. DISCUSSION: MANAGEMENT - BEYOND CONTROL

SOS-arsenic.net

ARTICLES

1. Arsenic: Growing menace

2. Ravages of arsenic poisoning

3. Arsenic Threat

4. A market basket survey of inorganic arsenic in food

5. Hydrogeological investigation of ground water arsenic contamination in south Calcutta

6. SEARCHING FOR SOLUTIONSby Sylvia Mortoza

6. SEARCHING FOR SOLUTIONSby Sylvia Mortoza

7. ARSENIC REVISITEDby Sylvia Mortoza

8. WATER POLLUTION IN THE GANGES BRAHMAPUTRA DELTA PLAIN

3. POLLUTION FROM AGRICULTURE

4. DISCUSSION: MANAGEMENT - BEYOND CONTROL

6. SEARCHING FOR SOLUTIONS
by Sylvia Mortoza

6. SEARCHING FOR SOLUTIONS
by Sylvia Mortoza

7. ARSENIC REVISITED
by Sylvia Mortoza