Aspects of Environmental Degradation in Bangladesh


 M. Munir uz Zaman





Bangladesh is of considerable interest to the environmentalist on account of certain specific features. Some of these are as follows:


1.      Bangladesh is one of the largest deltas of the world, with three major river system the Ganges, The Brahmaputra and the Meghna. Each system has significant number of tributaries and distributaries.

2.      The total amount of water flow is vast, next only to the Amazon system. However there are significant variations in the availability of water between wet and dry seasons.

3.      The country has been largely created by the vast quantity of sediments carried by the river systems. The sediment deposits are thick, and has made the soil fertile suitable for a high level of agricultural activities.

4.      The population density is very high, in fact the highest in the world.

5.      Although the land area is only 55000 sq miles, it has significant biodiversity

6.      Bangladesh has more than a fair share of natural hazards, like floods and cyclones. When they occur there is not only loss of human and animal lives and property, they disrupt the normal economic activities. However such natural disasters hardly pose any long - term threat to ecology.


The above features, true as they are, may create an impression that the country is gifted with plenty of life supporting water, good soil for farming activities and clean air as considerable bio-diversity would suggest. Unfortunately in recent decades, the state of environment has been showing signs of serious stress as revealed through a number of field observations and studies.*


The state of environment degradation may be approached by examining four key areas:

a)      Water pollution and scarcity

b)      Land degradation

c)      Air pollution

d)      Extent of bio-diversity


A state of environmental degradation is driven basically by, (a) population growth, and (b) application of unfriendly technology. In most cases, if not all, the presence of both has been at work in Bangladesh. The pressures of these two factors will be evident as the key features of degradation mentioned above are briefly examined.


Water Scarcity and Pollution


In the past there had been a secular decline in surface water availability in the north and south western part of Bangladesh sometimes called ‘moribund delta’, as tributaries of the Ganges in the north and distributaries in the south began to silted up. The process was

accelerated by the upstream of diversion of water from the river system for consumptive and non consumptive uses. The reduced availability of surface water in the region adversely affected the normal recharge of the ground water table in a number of areas. A smaller surface water run off also impacts on salinity level in the coastal areas. For example: in Khulna area during the dry season of the 1990s salinity line moved further inland.


The surface water quality is affected by untreated industrial effluents, Municipal waste water and run off from the surface of the agricultural lands treated with pesticides and chemical fertilizers. Pollution problems in the rivers close to the industrial areas are exceedingly high. For example: The dissolved oxygen (DO) level in the Buriganga has been found to be very low, and hence toxic. The Sitalakhya, Turag and Balu are also highly polluted. The water quality in Dhaka is so poor that the Environment Department of Bangladesh in a report said that “the water from surrounding rivers can no longer be considered as a supply source for human consumption.”**


Unlike Chittagong and a number of lesser urban centres, the requirement of potable water in the city of Dhaka is met entirely by groundwater abstraction. Excessive abstraction under pressures of increasingly larger population may further lower the ground water table and expose certain areas to serious scarcity and even land subsidence. The possibility of such a danger has to be seriously investigated. In any event the use of surface water as an important source of drinking water in the city of Dhaka brooks no further delay.


The levels of arsenic contents in the ground water is of major concern in Bangladesh. Prolonged use of water with arsenic concentration above the nationally recommended maximum of 0.05mg/ 1 for drinking purposes may pose serious hazards. The problem has assumed a serious dimension in specific areas in the south – west and south- east regions. The seriously affected areas are around Chandpur. According to an estimate about 20 million people drink water exceeding the safe arsenic level.


Soil Degradation


Land degradation varies according to regions. Land degradation in the flood plains is chiefly  attributable  to improper use of fertilizer and pesticides. In the coastal areas it is partly due to the nature of shrimp culture which requires letting in saline water into empoldered shrimp beds. Erosion of topsoils in the hilly districts has increased. It is estimated that 17% of the soil in the hilly districts has deteriorated between 1964 and 1985. Excessive irrigation of agricultural lands may also contribute to soil degradation. For example: it was observed in Chandpur irrigation project area that deficiency of Zinc content in the soil had occurred through leaching. The deficiency was corrected simply by injecting Zinc into the soil of the affected areas. Soil resources development institute (SRDI) has found that Nitrogen deficiency is a common phenomenon in the country. In Sylhet areas Phosphorus deficiency in the soil has been noticed.


In order to combat the adverse effects the government started a program of integrated pest management (IPM) from 1981. The program has made immense contribution to containing the bade of the use of pesticides for crop production as a whole. It has also helped reduce the application of pesticides. Another concept that is emerging is integrated plan nutrient system (IPNS) involving application of external nutrients based on soil capacity and crop need.


Air Pollution


The air quality of the country is generally good. However in urban areas particularly in Dhaka and Chittagong the air quality has deteriorated. Two major sources of air pollution are vehicular emissions and industrial emissions. A study on the presence of the suspended air particulate mass (APM) revealed that the concentration of APM in these two cities exceeds the threshold limits set by the Department of Environment.( Report by the Department of Environment). In recent years government have undertaken a number of measures to contain air pollution in the major urban centres. The important ones are:


a)      Banning the use of two stroke engine vehicles. Such engines emit unburned hydro- carbons and carbon monoxide 30-100 times more than four stroke engines. It is expected that two stroke engines will be will  be phased out through out the country over a short period of time.


b)      Introduction and promotion of increased use of compressed natural gas (CNG) in vehicles in place of gasoline.


c)      Leaded gasoline is another major air pollutant. In 1999 the Government decided that only unleaded patrol would be supplied.


A few more steps in protecting the city air is possible. The Department of Environment claims that pollution from vehicular emissions can be reduced by about two thirds by the use of low smoke lubricants and inspection and maintenance of vehicles. However industrial emission continues to be serious problem. Though the solution is more complex and probably more costly it has to be addressed seriously.


Bio Diversity


Bio diversity in Bangladesh is significant. Rivers and inland water bodies supports over 200 indigenous fish species and 150 species of birds. The marine water bodies harbour about 442 species of fish and 36 species of shrimps as well as significant number of crabs and turtules.


The Sunderbans, one of the largest mangrove forests in the world, supports 300 species of plants, 400 species of fish and over 200 species of birds. It is also the feeding area of migratory birds during winter.


However like other sectors of Bangladesh ecology, the diverse biological resources are also threatened by human intervention. The threat is most visible in the fisheries and forestry sectors. Forest areas already small as a proportion of the total land area, is being depleted by the combined pressure from timber extraction, encroachment by expanded agricultural activities and by the land grabbers. The forest area like Madhupur, once the home of many species of flora and fauna, has thinned out significantly in recent years. Shrimp culture owing to the method of cultivation, has an adverse effect on soil condition, vegetation and crop production in the area. These are due mainly to intrusion of saline water into the shrimp beds and deposition of suspended silt that comes along with the saline water.


Overfishing under conditions of population pressures has depleted the fish resources. Hilsa fish for which Bangladesh was once famous is no longer available in plenty. Despite the presence of a law prohibiting  the catch of fish below certain specified size, large quantities of Hilsa fry (Jhatka) are caught ever year and find their way into small markets.***


Bangladesh is a signatory to the Rio convention on bio-diversity and as such is bound by the international guidelines for conservation of plants and animal lives. The international union for conservation and nature (IUCN) in its red list had included 54 species of inland fish, 58 reptiles, 41 resident birds and 40 mammals as having been threatened with extinction in Bangladesh. The National Herbarium has listed 96 plants as threatened species. The list may not be very large considering the present extent of biodiversity with about 10,000 species of animals and plants in the country. However, in view of the nature of human activities in overexploiting the habitat of these species, there is little reason to be complacent.


It is evident from the brief discussions in the preceding paragraphs that the ecology of Bangladesh has been deteriorating under pressures of population and industrialization and urbanization. Historically speaking it is a fairly recent phenomenon. Since the polluting agents are different, each case will have to be studied separately warranting  a micro level approach.


A foremost task will be to build a measure of   public awareness of the danger to the quality of human life. The work undertaken by the civil society groups and the government needs to be pursued and further expanded. The subject of environmental concern could part of the educational policy and can be integrated in the teaching programs at school level.


Although a good number of laws for containing pollution have been enacted, their implementation has been uneven. For example: the laws regarding aspects of industrial pollutions have not always been rigorously implemented. Even of when a sound decision has been taken, its implementation gets delayed or is bogged down on various grounds. Relocation of the tanneries at Hazaribag is a case in point. Another example is the unabated catch of fish fries despite the presence of very clear legal provision for handling the offense.






Bangladesh State of Environment Report, 2001, Department of Environment/UNEP

Bangladesh Environment 2001, Unnyan Shamannay, University Press.

Environment and Poverty, ed. Atiq Rahman, The University Press.

Report on leather industry, report by MA, Redwan Billah; ed Philip Gain et al, published by SHED.




* State of Environment (SOE report) of the Department of Environment/UNEP: 2001, NGO reports like Unnayan Samanaya, University Press.

** State of Environment Report, Department of Environment 2001.

*** Peoples’ Report on Bangladesh Environment v1 by Atiur Rahman,, University Press (ch4).