Statement of the problem:
In a sound environment essential elements are present in proper ratio. Presence of more or less essential elements or harmful elements creates pollution. Pollution is now everywhere in Dhaka and symptom is very clear to us. For development, industrialization is essential but these industries are creating pollution. Industries are releasing poisonous gases, smokes and some other wastes. Generally the side of the rivers locates industries and wastes are polluting water seriously. These pollutants are harming trees, birds, animals and even human. Many diseases are being produced by the affect of pollution. Also various species of plants and animals are being extinct from the earth due to these hazardous conditions.
So, we have to know who is responsible for this crisis, how to solve the problems and who will take the initiatives? For solving the problem first we have to identify the nature of the problem. It is easy to solve the problem if we can identify how industrial wastes are causing pollution to environment.
Environmental Pollution is an international journal that focuses on papers that report results from original research on the distribution and ecological effects of pollutants in air, water and soil environments and new techniques for their study and measurement. Findings from re-examination and interpretation of existing data are also included. Theeditors are focusing on papers that provide new insights into environmental processes and or the effects of pollutants.
The editors discourage papers which describe results from routine surveys or routine monitoring programs, which are more local in interest than regional or global. Descriptions of a particular chemical in yet another situation are discouraged.
Objectives of preparing this Term Paper:
- Ø To identify responsible factor of pollution.
- Ø To determine the results of industrial wastage pollution.
- ØTo find out the ways of prevent pollution.
For limitation of time, it was not possible to collect data from primary sources. So, in this study I use the data from secondary sources (Different books, Journals, Newspapers, Sources from Internets etc.). In this term paper, identification of the problem, data presentation & analysis data and critical methods are used.
Every work has some limitations. The topic of the term paper is totally related to various types of industries. So, to prepare this paper it was not possible for me to collect data from primary sources due to shortage of time. Insufficient related books, journals etc. for secondary data is also another obstacles. So I mainly depend on Internet sources. For this reason I had to present and analyze data quickly. With these limitations I tried my best to make good paper.
Environment and Pollution
Environment : The term “Environment” means our surroundings, which comprises of land, water and air and other bodies. Environment is affected by the physical properties of these components. It is also affected by the changes in interrelationship prevailing between and among the components ranging from micro-organism to human bodies. Our life-support system is maintained by all the species that make up the biosphere-biodiversity. The survival of all these species is interconnected and dependent on each other. Human being is also a part of this biosphere; extinction of one species is really the extinction of many species and the decline of our life-support system for future generations and us. So, all the components of the environment are equally important for human being as well as for the other species.
Types of Environment
Environment can be conveniently divided into two categories:
a) Natural Environment
b) Man-made or Anthropogenic Environment
Man-made environment includes:
|a) Technology.||b) Transportation|
|c) Agricultural implements||d) Dam-building|
|e) Housing||f) Industrial Revolution|
|g) Revolution in Communication e.g. satellite, FAX etc.|
|h) Space Acceleration, landing of man on moon.|
|i) Space Laboratories|
|j) Computerization etc.|
Pollution: The word ‘pollution’ derived from the Latin word ” pollution’ * (meaning to defile of make dirty). Pollution can be defined in various ways. Pollution is an undesirable change in physical, chemical or biological characteristics of water, air and soil that may harmfully affect human, animal and the plant life, industrial progress, living conditions and cultural assets. Pollution is usually brought about by the addition of wastes. The materials, which cause pollution of environment, are called pollutants.
Types of Pollution:
Classification according to environment:
I. Air Pollution
II. Water Pollution
III. Soil or Land Pollution
Air pollution :
Air pollution is the introduction of chemicals, particulate matter, or biological materials that cause harm or discomfort to humans or other living organisms, or cause damage to the natural environment or built environment, into the atmosphere.
The atmosphere is a complex dynamic natural gaseous system that is essential to support life on planet Earth. Stratospheric ozone depletion due to air pollution has long been recognized as a threat to human health as well as to the Earth’s ecosystems. A substance in the air that can cause harm to humans and the environment is known as an air pollutant. Pollutants can be in the form of solid particles, liquid droplets, or gases. In addition, they may be natural or man-made.
Pollutants can be classified as primary or secondary. Usually, primary pollutants are directly emitted from a process, such as ash from a volcanic eruption, the carbon monoxide gas from a motor vehicle exhaust or sulfur dioxide released from factories. Secondary pollutants are not emitted directly. Rather, they form in the air when primary pollutants react or interact. An important example of a secondary pollutant is ground level ozone — one of the many secondary pollutants that make up photochemical smog. Some pollutants may be both primary and secondary: that is, they are both emitted directly and formed from other primary pollutants.
Major primary pollutants produced by human activity include:
- Sulfur oxides (SOx) – especially sulphur dioxide, a chemical compound with the formula SO2. SO2 is produced by volcanoes and in various industrial processes. Since coal and petroleum often contain sulphur compounds, their combustion generates sulfur dioxide. Further oxidation of SO2, usually in the presence of a catalyst such as NO2, forms H2SO4, and thus acid rain. This is one of the causes for concern over the environmental impact of the use of these fuels as power sources.
- Nitrogen oxides (NOx) – especially nitrogen dioxide are emitted from high temperature combustion. Can be seen as the brown toxic gas has a characteristic sharp, biting odor. NO2 is one of the most prominent air pollutants.
- Carbon monoxide – is a colourless, odorless, non-irritating but very poisonous gas. It is a product by incomplete combustion of fuel such as natural gas, coal or wood. Vehicular exhaust is a major source of carbon monoxide.
- Carbon dioxide (CO2) – a colourless, odorless, non-toxic greenhouse gas associated with ocean acidification, emitted from sources such as combustion, cement production, and respiration
Volatile organic compounds – VOCs are an important outdoor air pollutant. In this field they are often divided into the separate categories of methane (CH4) and non-methane (NMVOCs). Methane is an extremely efficient greenhouse gas which contributes to enhanced global warming. Other hydrocarbon VOCs are also significant greenhouse gases via their role in creating ozone and in prolonging the life of methane in the atmosphere, although the effect varies depending on local air quality. Within the NMVOCs, the aromatic compounds benzene, toluene and xylene are suspected carcinogens and may lead to leukemia through prolonged exposure.
- Particulate matter – Particulates, alternatively referred to as particulate matter (PM) or fine particles, are tiny particles of solid or liquid suspended in a gas. In contrast, aerosol refers to particles and the gas together. Sources of particulate matter can be man made or natural. Some particulates occur naturally, originating from volcanoes, dust storms, forest and grassland fires, living vegetation, and sea spray. Human activities, such as the burning of fossil fuels in vehicles, power plants and various industrial processes also generate significant amounts of aerosols. Averaged over the globe, anthropogenic aerosols—those made by human activities—currently account for about 10 percent of the total amount of aerosols in our atmosphere. Increased levels of fine particles in the air are linked to health hazards such as heart disease, altered lung function and lung cancer.
- Persistent free radicals connected to airborne fine particles could cause cardiopulmonary disease.
- Toxic metals, such as lead, cadmium and copper.
- Chlorofluorocarbons (CFCs) – harmful to the ozone layer emitted from products currently banned from use.
- Ammonia (NH3) – emitted from agricultural processes. Ammonia is a compound with the formula NH3. It is normally encountered as a gas with a characteristic pungent odor. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to foodstuffs and fertilizers. Ammonia, either directly or indirectly, is also a building block for the synthesis of many pharmaceuticals. Although in wide use, ammonia is both caustic and hazardous.
- Odors — such as from garbage, sewage, and industrial processes
- Radioactive pollutants – produced by nuclear explosions, war explosives, and natural processes such as the radioactive decay of radon.
Air pollution by Chemical Industries:
Air pollution in capital city Dhaka has gone higher than Mexico City and Mumbai killing thousands prematurely each year. According to the Department of Environment (DoE), the density of airborne particulate matter (PM) reaches 463 micrograms per cubic meter (mcm) in the city during December-March period – the highest level in the world. Mexico City and Mumbai follow Dhaka with 383 and 360mcm respectively. An estimated 15,000 premature deaths, as well as several million cases of pulmonary, respiratory and neurological illness are attributed to poor air quality in Dhaka, according to the Air Quality Management Project (AQMP), funded by the government and the World Bank.
If pregnant mothers come across excessive pollution, it may cause premature death of their children. According to the National Institute of Diseases of Chest and Hospital (NIDCH), nearly seven million people in Bangladesh suffer from asthma; more than half of them are children. Cases of children suffering from bronchitis and chronic cough have also shot up in recent years. Children breathe more air relative to their lung size than adults. They spend more time outdoors, often during midday and afternoons when pollution levels are generally highest. WHO air quality guidelines (2005) recommend a maximum acceptable PM level of 20mcm; cities with 70mcm are considered highly polluted. Airborne lead is the worst of the harmful PMs.
By penetrating the lungs and entering the blood stream, lead may cause irreversible neurological damage as well as renal disease, cardiovascular effects, and reproductive toxicity. The phasing out of petrol-driven two-stroke auto-rickshaws in 2003 and their replacement with four-stroke versions, which use a much cleaner burning fuel (compressed natural gas), significantly decreased the volume of air contaminants. But, according to DoE sources, a sharp increase in the number of vehicles and construction sites in 2004-2008 led to a deterioration of Dhaka’s air quality.
Bangladesh is still at its initial phase of industrialization. But it does not mean that the risk of air pollution is less here. Bangladesh is the world’s most densely populated country, , which means if pollution occurs at any place by even one polluting agent, a big population remain at the risk of being exposed to it.
At the moment, the country has 30,000 industrial units of which 24,000 rank among the cottage industry. The main industries of the country can be divided into two categories based on renewable local resources and non-renewable local resources. Industries based on renewable local resources are jute, pulp, paper, match, sugar, tobacco, leather, salt and other agro-based industries. Examples of industries based on non- renewable local resources are the natural gas based industries, ceramic industries, brickfields, etc.
A large number of industries in Bangladesh are not located in proper places. Many hazardous and polluting industries are located near residential areas. The air adjacent to a factory is usually contaminated by the poisonous gases and dust which emit from the industrial units. Mercaptan chlorine is emitted from the pulp and paper mills. Urea fertilizer factories emit urea dust and ammonia gas. A TSP [fertilizer] plant pours out a huge quantity of dust-20 MT of dust a day on average.
Among all the industries, jute mills are the worst. One per cent of all raw materials used in the jute mills is thrown into the air as dust and waste. Workers of jute mills suffer from respiratory problems due to their long hours of exposure to polluted air.
In almost every town in Bangladesh, welding factories, oil mills, pulse factories are located close to residential areas; engineering workshops are often found adjacent to educational institutions.
In the Tejgaon industrial area of Dhaka, Faruk Chemical Industries is located close to Nabisco Biscuit Factory. There is a heavy metal industry adjacent to Polar Ice Cream Factory. Kohinoor chemicals factory is located near Haque Biscuits Factory.
In parts of old Dhaka, the most densely populated areas of the city, hundreds of legal and illegal welding factories are at work. Carbon monoxide gas emits from these factories during welding. There are many small factories in Dholaikhal, Moishundi, Sutrapur, Rokonpur, Gandaria, Narinda, Najimuddin Road, Tipu Sultan Road, Hajaribagh, etc. Most of the factories built in the residential areas are illegal. Smoke and stench radiating from these factories have made life difficult for the local inhabitants.
In Chittagong there are 144 polluting industries located in different industrial areas. Among these are 19 tanneries, 26 garment industries, one oil refinery ,one DDT (now closed) factory, two chemical factories, five fish processing industries, two cement, one paper and rayon, two steel, two soap, two pesticide, four dye manufacturing factories and 75 other small industries.
Most industries in Bangladesh do not have any waste recycling plant or system, which is simply essential for any industry discharging pollutant.
Leather sector also produces 150 tons solid waste a day
The leather industry sector, which is the fourth largest foreign exchange earner of the country contributing about six per cent of total export earnings, produces 150 metric tons of solid waste every day contaminating the environment and water of the metropolis.
59 per cent of the total wastage comes from processing of hides and skin, and accumulates in the swamp-sludge, experts in the environment sector said. The experts said, “part of the solid waste is collected by the Dhaka City Corporation (DCC) and taken to landfill sites.”
A recent research conducted by Professor S M Imamul Huq, Chairperson of Soil, Water and Environment Department of Dhaka University revealed that out of 214 tanneries in the country, except for two BATA and Dhaka Leather Complex-none of the tanneries has a treatment plant as required by the law.
Rice and wheat were grown in a pot experiment in soils from the tannery area. The wheat showed delayed maturity and stunting growth while rice showed late flowering and maturity with dark green colour. In another experiment it was observed that application of tannery effluents to soils of differing textures resulted in reduction of yield of rice, the research said adding that the adverse effect was more pronounced in light soils than in heavy soils. The effluent was also found to negatively affect performance, nodulation and growth of mung beans (dal).
In his research article named “Critical Environmental Issues Relating to Tanning Industries in Bangladesh,” Professor Imamul Huq said, “most of the waste effluents are subjected to natural decomposition in the environment, causing serious pollution problems affecting soil, water, air and human life.”
The finding said that the existing industries in most cases do not have any effluent treatment plants for neutralising the toxicity and harmful effects of their pollutants.
The research recommended building of appropriate waste treatment plants for neutralising harmful chemicals before disposal of the waste into the environment and called upon the government to fix a legal limit value for discharge of tannery effluent to surface water.
Stressing the need for treatment methods to combat pollution including segregation of processed waste water, sedimentation, neutralisation and biological treatment, the paper said that about half the tanneries apply some kind of solid waste reuse, while 90 per cent of the finished trimming wastes are used by the local shoemakers.
The research said, “the process of tanning produces both liquid and solid wastes. Solid wastes are from the initial and final stages of processing while the effluents are produced mostly during tanning and dying.” The 149 operating tanneries produce 14910 metric tons of effluents or waste water during the peak time, about 9100 metric tons during the off-peak period, the research paper said adding that the effluents contain dissolved lime, hydrogen sulfide, acids, chromium dyes, oils, organic matter and suspended solids.
“The waste water is discharged into open drains and ultimately finds way onto land surface and into natural waters in the vicinity,” the research revealed. It says “about 3000 tons of sodium sulfide and nearly 3000 tons of basic chromium sulfate are used each year for leather processing and tanning.” The other chemicals used in the tanning industry are non-ionic wetting agents, bactericides, soda ash, calcium oxide, ammonium sulfate, ammonium chloride, enzymes, sodium bisulfate, sodiumchlorite, sodium hypochlorite, sodium chloride, sulfuric acid, formic acid, sodium formate, sodium bicarbonate, vegetable tannins, syntans, resins, polyurethane, dyes, fatemulsions, pigments, binders, waxes, lacquers and formaldehyde.
Out of 214 tanneries, 200 are located near the capital’s river systems – the Turag to north-west, the Buriganga to the south-west and the Sitalakhya to the south-east, with Turag flowing into the Buriganga.
The tanneries discharge the effluents and wastes into the river system causing a large area of acid sludge alongside the flood protection embankment and the liquid wastes are dumped in the river through a flood control regulator-cum-sluice.
During monsoon months, the flood protection embankments protect Dhaka from heavy flooding while making it difficult to flush-out waste water, thereby creating environmental hazard. During the dry season the waste water is flushed out into the river causing pollution of the river water and affecting the aquatic flora and fauna. The dumping of the solid wastes is seriously affecting the soil and plants, besides vitiating the air, groundwater and human health.
The water quality of the river Buriganga during wet season and dry season are heavily polluted so that dissolved oxygen in the river water is found to be nil during the dry season and no fish or other aquatic animals can live in this condition.
(Source: The Independent, May 09, 2006)
Air Pollution contamination of the atmosphere caused by the discharge, accidental or deliberate of a wide range of toxic substances. Often the amount of the released substance is relatively high in a certain locality, so the harmful effects are more noticeable. The major sources of air pollution are transportation engines, power and heat generation, industrial processes and the burning of solid waste. A new source of air pollution is an increasing ‘hole’ in the ozone layer in the atmosphere above Antarctica, coupled with growing evidence of global ozone depletion. Air pollution has also long been known to have an adverse effect on human beings, plants, livestock and aquatic ecosystem through acid rain.
Recently as in other parts of the world air pollution has received priority among environmental issues in Asia. This problem is acute in dhaka, the capital of Bangladesh and also the hub of commercial activity. The other urban areas like chittagong, khulna, bogra and rajshahi have much lesser health problem related to air pollution. In urban areas sometimes the houses are built on rocks and soils, which radiate radioactive gas from their basement. If this gas is inhaled for a long time it may cause lung cancer. In the rural areas of Bangladesh, the air pollution problems have not yet become a point of concern. This is due to fewer motorised vehicles and industries there. However, brick kilns and cooking stoves are the principal sources of emission in rural areas. In villages wood, coal, and biomass are used as sources of energy. Thus, it is likely that in those areas the principal air contaminants are particulate matter and volatile organic compounds (VOCs).
Basically, there are two major sources of air pollution in Bangladesh industrial emissions and vehicular emissions. The industrial sources include brick kilns, fertiliser factories, sugar, paper, jute and textile mills, spinning mills, tanneries, garment, bread and biscuit factories, chemical and pharmaceutical industries, cement production and processing factories, metal workshops, wooden dust from saw mills and dusts from ploughed land, and salt particles from ocean waves near the offshore islands and coastal lands. These sources produce enormous amount of smokes, fumes, gases and dusts, which create the condition for the formation of fog and smog. Certain industries in Bangladesh, such as tanneries at Hazaribag in DhakaCity, emit hydrogen sulphide, ammonia, chlorine, and some other odorous chemicals that are poisonous and cause irritation and public complaints. This may cause headache and other health problems.
With increased rate of urbanisation in the country, the number of vehicles is also increasing rapidly, and contributing to more and more air pollution. The Department of Environment (DOE), and other related organisations, have identified the two-stroke engines used in autorickshaws (baby-taxies), tempos, mini-trucks, and motorcycles as major polluters. At present, there are about 65,000 baby-taxies among them more than 296,000 motor vehicles ply in DhakaCity alone. Moreover, overloaded, poorly maintained and very old trucks and mini-buses are also plying the city streets emitting smokes and gases. In fact about 90% of the vehicles that ply Dhaka’s streets daily are faulty, and emit smoke far exceeding the prescribed limit. Diesel vehicles emit black smoke, which contain unburned fine carbon particles.
The two-stroke engines are now discouraged in Bangladesh because of their pollution hazard. In view of the serious automobile pollution faced in the metropolis, an initiative was taken with World Bank support to introduce big buses in the city and discourage the ply ing of small automobiles, including baby-taxis. The introduction of air-conditioned city bus service is an outcome of that initiative.
Sophisticated equipment is now being used to detect air polluters in Bangladesh. As such, four monitoring stations are set up at four divisional towns, namely, Dhaka, Chittagong, Khulna, and Bogra. In Dhaka the locations of vehicular emission test are at Tejgaon, Farmgate, Manik Mia Avenue, Gulshan, Lalmatia, and Agargaon. bangladesh university of engineering and technology (BUET) has also been conducting ambient air quality surveys since 1995.
The air quality standards are different for residential, industrial, commercial, and sensitive areas. The worst affected areas in Dhaka city include: Hatkhola, Manik Mia Avenue, Tejgaon, Farmgate, Motijheel, Lalmatia, and Mohakhali. Surveys conducted between January 1990 and December 1999 showed that the concentration of suspended particles goes up to as high as 3,000 micrograms per cubic meter (Police Box, Farmgate, December 1999), although the allowable limit is 400 micrograms per cubic meter. The sulphur dioxide in the air near Farmgate was found to be 385 micrograms per cubic meter, where as the maximum permissible limit is 100 micrograms per cubic meter. Similarly, in the Tejgaon Industrial Area the maximum concentration of suspended particles was 1,849 micrograms per cubic meter (January 1997), as opposed to the allowable limit of 500 micrograms per cubic meter. Usually the maximum concentration of air pollution in Dhaka is during the dry months of December to March.
The bangladesh atomic energy commission (BAEC) and the Bangladesh Council of Scientific and Industrial Research (BCSIR), in collaboration with the DOE, recently assessed the concentration of lead in the ambient air. The dhaka shishu hospital in association with the BAEC also estimated the level of lead in the blood of children of DhakaCity and the possible impact of leaded gasoline on them. The Bangladesh Road Transport Authority (BRTA) is also setting up a vehicle emission monitoring station at Mirpur, Dhaka.
Prior to introduction of unleaded gasoline, BAEC reported that the air that city dwellers breathe on the roads contains lead in concentrations almost ten times above the government safety standard set by the DOE. The air of DhakaCity holds 463 nanograms per cubic meter of lead – the highest in the world. From November 96 to March 97 the lead levels in three different areas of DhakaCity were 123-252 nanograms per cubic meter at Farmgate area and 61 to 76 nanograms per cubic meter in Tejgaon Industrial area.
The lead poisoning produces neuro-developmental disorders in children. About 50 tons of lead is emitted in the Dhaka air annually and the emission reaches its highest level in the dry season from November to January. Lead poisoning has been detected recently in children at the Shishu Bikash Kendro (Child Development Centre) of DhakaShishuHospital. Lead concentrations, measured around 80-micrograms/dl-to180 micrograms/dl in the tested children’s blood, is 7-16 times more than the acceptable limit. The safe concentration advocated by the US Centre for Disease Control and Prevention is 10 micrograms/dl. People living in urban slums have a significant rise in mean blood lead levels, compared to those living in urban middle-income or rural areas. The development of lead pollution could also affect the central nervous system, cause renal damage and hypertension. Excessive lead in the blood of children could damage-their brain and kidney. Children are three times more at risk than adults are by exposure to lead poisoning.
In Dhaka city the mean blood lead level of rickshaw pullers is 248 micrograms/dl (range 154-344 micrograms/dl), baby-taxi drivers 287 micrograms/dl, traffic police 272 micrograms/dl (range 152-32 micrograms/dl), tempo assistants 255 micrograms/dl, and petrol pump operators 249 micrograms/dl (range 207-342 micrograms/dl). The mean blood lead level among these risk groups is found to be higher than the acceptable value, with traffic police being the worst affected group. The blood lead levels usually increased with duration of exposure.
During July 1999 the Government of Bangladesh (GOB) executed the decision to provide only unleaded gasoline in the country. According to recent measurements between late 1999 and 2000 by BAEC and eastern refinery limited (ERL) the gasoline dispensed at pumps in Bangladesh is now totally free of lead.
It has been found that Dhaka city has VOC beyond tolerable limits, some of which cause cancer. Emissions from two-stroke auto-rickshaws in Dhaka were found to contain 4 to 7 times the maximum permissible level of VOC.
Dust pollution is causing many respiratory diseases, including asthma. Recently, 200 organic compounds are detected by analysing four air samples collected from the Shewrapara area of the city. As far as the VOC is concerned the following worst affected areas are identified: Hatkhola, Manik Mian Avenue, Tejgaon, Farm Gate, Motijheel, Lalmatia, and the inter-district bus terminals. Surveys conducted between December 1996 and June 1997 showed that the concentration of suspended particles goes up to as high as 2,465 micrograms per cubic metre as against the allowable limit of 400 micrograms per cubic metre at Farm Gate. In Tejgaon Industrial Area, on the other hand, the maximum con centration of suspended particles was 630 micrograms as against the allowable limit of 500 micrograms per cubic metre.
Mine air pollution a major issue of concern in Bangladesh. Dust and mine gases create problems for coalmine. Fortunately barapukuria coal of dinajpur district has insignificant gas content, therefore, in the process of mining of coal the danger of methane emission and methane gas related hazards are considered to be insignificant. As the Barapukuria coal will be mined mechanically, huge coal dusts would be generated but proper mitigation measures if taken coal dust could be controlled. Huge dusts will also be generated in the Maddhyapara hardrock mine in Dinajpur district, due to frequent movements of heavy vehicles together with required loading and unloading operations. The gases formed by the combustion of coal, fuel and lubricants in the mine both at the surface and underground pollute the ambient air. Dusts generated from coal and hardrocks especially during cutting, blasting, crashing and transportation in the mines are generally the cause of concern for the miners and for the surrounding localities.
Government decisions recently the Ministry of Energy and Mineral Resources (MEMR) has taken important decisions, which are as follows (i) the minimum standard of lubricating oil for two- stroke engine should be APITC or JASOEB and (ii) marketing of straight mineral oil should stop immediately.
In 1985-86 the bangladesh petroleum corporation started a project to use compressed natural gas (CNG) in vehicles instead of gasoline. The primary objective was to reduce vehicular emissions, as combustion of CNG produces less pollution than gasoline. The World Bank donated Taka 225 million to initiate the project. So far data on the number of vehicles converted to CNG from 1985 to 1997 are as follows: 1985-86 converted vehicles 2; 1988-89 converted vehicles 19; 1989-90 converted vehicles 9; 1990-91 converted vehicles 6; 1991-92 converted vehicles 10; 1992-93 converted vehicles 16; 1993-94 converted vehicles 3; 1995-96 converted vehicles 13 and 1996-97 converted vehicles 86. Private sector participation in using CNG for taxicabs is significant. At the beginning of 2002 the Government has started promotional campaign and appropriate push to the owners of autorickshaws to use CNG in order to reduce vehicular emissions.
Pollution policy the first regulation related to environment in Bangladesh was the Factory Act of 1965, which was followed by the earliest recorded environmental protection act, known as the ‘Water Pollution Control Ordinance, 1970’. However, these ordinances do not include air pollution problems. Gradually these ordinances were modified and the Environmental Pollution Control Ordinance (EPC), 1977, was promulgated. It dealt with pollution of air, surface water and groundwater, and soil by discharge of liquid, gaseous, solid, radioactive, or other substances. Although the order passed under the EPC 1977 was legally in place, implementation of environmental laws never took place.
Following rapid industrialisation the environmental scenario in Bangladesh changed dramatically. The Ministry of Environment and Forest and the Department of Environment were created in 1989 and the Environment Policy of 1992 was introduced. Further, the Environmental Conservation Act, 1995, and the Environment Conservation Rules, 1997, were approved by the Bangladesh National Assembly to restrict and mitigate ever-growing environmental problems in the country. [Sifatul Quader Chowdhury]
Bibliography United Nations Environment Programme, State of the Environment: Bangladesh, United Nations Environment Programme, 2001.
There are various air pollution control technologies and land use planning strategies available to reduce air pollution. At its most basic level land use planning is likely to involve zoning and transport infrastructure planning. In most developed countries, land use planning is an important part of social policy, ensuring that land is used efficiently for the benefit of the wider economy and population as well as to protect the environment.
Efforts to reduce pollution from mobile sources includes primary regulation (many developing countries have permissive regulations), expanding regulation to new sources (such as cruise and transport ships, farm equipment, and small gas-powered equipment such as lawn trimmers, chainsaws, and snowmobiles), increased fuel efficiency (such as through the use of hybrid vehicles), conversion to cleaner fuels (such as bioethanol, biodiesel, or conversion to electric vehicles).
The following items are commonly used as pollution control devices by industry or transportation devices. They can either destroy contaminants or remove them from an exhaust stream before it is emitted into the atmosphere.
- Particulate control
- Mechanical collectors (dust cyclones, multicyclones)
- Electrostatic precipitators An electrostatic precipitator (ESP), or electrostatic air cleaner is a particulate collection device that removes particles from a flowing gas (such as air) using the force of an induced electrostatic charge. Electrostatic precipitators are highly efficient filtration devices that minimally impede the flow of gases through the device, and can easily remove fine particulate matter such as dust and smoke from the air stream.
- Baghouses Designed to handle heavy dust loads, a dust collector consists of a blower, dust filter, a filter-cleaning system, and a dust receptacle or dust removal system (distinguished from air cleaners which utilize disposable filters to remove the dust).
Particulate scrubbersWet scrubber is a form of pollution control technology. The term describes a variety of devices that use pollutants from a furnace flue gas or from other gas streams. In a wet scrubber, the polluted gas stream is brought into contact with the scrubbing liquid, by spraying it with the liquid, by forcing it through a pool of liquid, or by some other contact method, so as to remove the pollutants. The Air Quality Health Index or “AQHI” is a federal program jointly coordinated by Health Canada and Environment Canada. However, the AQHI program would not be possible without the commitment and support of the provinces, municipalities and NGOs. From air quality monitoring to health risk communication and community engagement, local partners are responsible for the vast majority of work related to AQHI implementation. The AQHI provides a number from 1 to 10+ to indicate the level of health risk associated with local air quality. Occasionally, when the amount of air pollution is abnormally high, the number may exceed 10. The AQHI provides a local air quality current value as well as a local air quality maximums forecast for today, tonight and tomorrow and provides associated health advice.
|Risk:||Low (1-3)||Moderate (4-6)||High (7-10)||Very high (above 10)|
As it is now known that even low levels of air pollution can trigger discomfort for the sensitive population, the index has been developed as a continuum: The higher the number, the greater the health risk and need to take precautions. The index describes the level of health risk associated with this number as ‘low’, ‘moderate’, ‘high’ or ‘very high’, and suggests steps that can be taken to reduce exposure.
Air Quality Health Index
|At Risk population||*General Population|
|Low||1-3||Enjoy your usual outdoor activities.||Ideal air quality for outdoor activities|
|Moderate||4-6||Consider reducing or rescheduling strenuous activities outdoors if you are experiencing symptoms.||No need to modify your usual outdoor activities unless you experience symptoms such as coughing and throat irritation.|
|High||7-10||Reduce or reschedule strenuous activities outdoors. Children and the elderly should also take it easy.||Consider reducing or rescheduling strenuous activities outdoors if you experience symptoms such as coughing and throat irritation.|
|Very high||Above 10||Avoid strenuous activities outdoors. Children and the elderly should also avoid outdoor physical exertion.||Reduce or reschedule strenuous activities outdoors, especially if you experience symptoms such as coughing and throat irritation.|
It is measured based on the observed relationship of Nitrogen Dioxide (NO2), ground-level Ozone (O3) and particulate matter (PM2.5) with mortality from an analysis of several Canadian cities. Significantly, all three of these pollutants can pose health risks, even at low levels of exposure, especially among those with pre-existing health problems.
When developing the AQHI, Health Canada’s original analysis of health effects included five major air pollutants: particulate matter, ozone, and nitrogen dioxide (NO2), as well as sulphur dioxide (SO2), and carbon monoxide (CO2). The latter two pollutants provided little information in predicting health effects and were removed from the AQHI formulation.
The AQHI does not measure the effects of odour, pollen, dust, heat or humidity.
Water pollution :
Water pollution is the contamination of water bodies (e.g. lakes, rivers, oceans and groundwater). Water pollution occurs when pollutants are discharged directly or indirectly into water bodies without adequate treatment to remove harmful compounds.
Water pollution affects plants and organisms living in these bodies of water; and, in almost all cases the effect is damaging not only to individual species and populations, but also to the natural biological communitiesChemical and other contaminants.
Muddy river polluted by sediment. Photo courtesy of United States Geological Survey.
Contaminants may include organic and inorganic substances.
Organic water pollutants include:
- Disinfection by-products found in chemically disinfected drinking water, such as chloroform
- Food processing waste, which can include oxygen-demanding substances, fats and grease
- Insecticides and herbicides, a huge range of organohalides and other chemical compounds
- Petroleum hydrocarbons, including fuels (gasoline, diesel fuel, jet fuels, and fuel oil) and lubricants (motor oil), and fuel combustion byproducts, from stormwater runoff
- Tree and bush debris from logging operations
- Volatile organic compounds (VOCs), such as industrial solvents, from improper storage. Chlorinated solvents, which are dense non-aqueous phase liquids (DNAPLs), may fall to the bottom of reservoirs, since they don’t mix well with water and are denser.
- Various chemical compounds found in personal hygiene and cosmetic products
Inorganic water pollutants include:
- Acidity caused by industrial discharges (especially sulfur dioxide from power plants)
- Ammonia from food processing waste
- Chemical waste as industrial by-products
- Fertilizers containing nutrients–nitrates and phosphates–which are found in stormwater runoff from agriculture, as well as commercial and residential use
- Heavy metals from motor vehicles (via urban stormwater runoff) and acid mine drainage
- Silt (sediment) in runoff from construction sites, logging, slash and burn practices or land clearing sites
Macroscopic pollution—large visible items polluting the water—may be termed “floatables” in an urban stormwater context, or marine debris when found on the open seas, and can include such items as:
- Trash or garbage (e.g. paper, plastic, or food waste) discarded by people on the ground, along with accidental or intentional dumping of rubbish, that are washed by rainfall into storm drains and eventually discharged into surface waters
- Nurdles, small ubiquitous waterborne plastic pellets
- Shipwrecks, large derelict ships
Thermal pollution is the rise or fall in the temperature of a natural body of water caused by human influence. Thermal pollution, unlike chemical pollution, results in a change in the physical properties of water. A common cause of thermal pollution is the use of water as a coolant by power plants and industrial manufacturers. Elevated water temperatures decreases oxygen levels (which can kill fish) and affects ecosystem composition.
Water Pollution By chemical industries:
The Buriganga river in Dhaka has become heavy polluted from sources such as waste flowing into the river, oil spills from boats and building structures appearing on the river banks. Dhaka, Bangladesh. 30/12/09.
In the distant past, a course of the Ganges river used to reach the Bay of Bengal through the Dhaleshwari river. This course gradually shifted and ultimately lost its link with the main channel of the Ganges and was renamed as the Buriganga.
Hundreds of years ago, the banks of the Buriganga were a prime location for trade when the Mughals made Dhaka their capital in 1610. It was the main waterway for trading. It is said that the water levels during high and low tides in this river astonished.40-50 years ago, a cruise on the historic Buriganga River in the capital used to be a must for visiting dignitaries. It was once the main source of drinking water for Dhaka residents, and the river is still crystal clear an hour upstream from the capital.
These days they are confronted with foul smells and rotting fish, the stench is unbelievable, according to the Environment Department, up to 40,000 tons of tannery waste flows into the river daily, along with sewage from Dhaka, a city of more than 10 million.
Different Types of Wastes Table- 1: Hazardous Waste
EXAMPLES OF HAZARDOUS WASTE GENERATED BY INDUSTRIES
|Chemical Manufacturers||Acids and Bases Spent Solvents Reactive|
Waste Wastewater Containing Organic
ConstituentsPrinting IndustryHeavy Metal Solutions Waste Inks Solvents Ink Sludges Containing Heavy
Metals.Petroleum Refining IndustryWastewater Containing Benzene & other! Hydrocarbons Sludge From Refining
Process.Leather Products ManufacturingToluene and Benzene.Paper IndustryPaint Waste Containing Heavy Metals Ignitable Solvents.Construction IndustryIgnitable pain waste spentsolvents strong Acids And Bases.Metal ManufacturingSludge’s Containing Heavy Metals Cyanide Waste Paint Waste.
Source: Environmental Protection Agency, Solving the Hazardous Waste Problem: EPA’s RCRA Program (Washington, DC: ERA, November 1986), 8,Industries are responsible for various types of wastes. Through these wastage water is polluted seriously. The textile and clothing industry is important for Bangladesh’s economic growth, but has brought with it a range of problems one of which is water pollution. Mokosh Beel in Kaliakoir Upazilla is one example of a now very polluted wetland particularly during the dry season. This is the case with all, it is an area of serious water pollution. Although poultry farms, pharmaceutical industries and a tannery have been established there, textile manufacturers, including dyeing and printing units, dominate the area. There are some elements, which pollute water.
Lead (Pb) Arsenic (As) Mercury (Hg} Cadmium (Cd)Pic-2 Water Pollution Through Industrial Waste waterBarium (Ba) Cobalt (Co) Chromium (Cr) Selenium (Se) Zinc (Zn) Copper(Cu) quality indicators In
Bangladesh Standard for inland surface water (mg/l)aRHedian
BOD (n = 7)6 or less407380-500COD (n = 7)*200.0 or less960350-1600DO (n = 7)5 or more10.6-1.2Sulfide (n = 7)*2.0 or less3.11.6-10.2
Source: GOB (1997); MACH (2001) *= standard for waste water quality when discharged in inland water surface (Chowdhury and Clemett 2006)
Pic-3 Gang^jjc Dolphin (Platanista gangetica), a threatened species associated with poor water quality in TuragRiver.
[Source: MACH (Management of Aquatic Ecosystems through Community Husbandry) is a Government of Bangladesh project supported by USAID].
Table-4 : Pathological effects of metal water pollutions on man
|Metal||Pathological Effects on Man|
Anaemia, vomiting, loss of appetite, convulsions, damage of liver, brain and kidney.Arsenic (As)
Disturbed peripheral circulation, mental disturbance, liver cirrhosis, hyperkeratosis, lung cancer, ulcers in gastro-intestinal tract, kidney damage.Mercury (Hg)
Abdominal pain, headache, diarrhea , chest pain, hemolytic.Cadmium (Cd)
Growth retardation, diarrhea, bone deformation, kidney damage, anemia, injury of central nervous system, hypertension, injury to lever.Barium (Ba)
Wxcessve salivation, vomiting, diarrhea, paralysis, colic pain.Cobalt (Co)
Diarrhea, low blood pressure, lung irritation, bone deformation, paralysis.Chromium (Cr)
Gastro intestinal ulceration, diseases in central nervous system, cancer, nephritis.Selenium (Se)
Damage of liver, kidney and spleen, fever, nervousness, vomiting, low blood pressure, blindness and ever death.Zink(Zn)Vomiting, cramps, renal damageCopper (Cu)Sporadic fever, hypertension, ui=emia, coma
Waste that pollutes Soil:
Industrial waste is responsible for soil pollution. Various industries create many types of solid and liquid wastes. When it mixed with soil it contaminate it and change the characteristic of soil. The main responsible industries are pulp and paper mills, chemical industries, oil refineries, sugar factories, tanneries, textiles, power plants, steel & iron industry, distilleries, fertilizers, pesticide industries, coal and mineral mining industries, metal processing industries, drugs, glass, cement, petroleum and engineering industries etc.
Cities also encourage or discourage certain types of industrial land use according to future development strategies. In many cities, new industrial parks often favor the inclusion of high-technology industries. This kind of proactive approach cause also generates pollution to soil.
Trees & some other plants totally depend on soil for th’eir nutrients, water and mineral. Fast industrialization also brought with the risk of soil pollution. It is the most important environmental factor. But this soil is contaminating and loosing its fertility. Many organic compounds and fly ashes are mixing with soil and polluting it seriously.
Effect of Pollution by Industrial Waste
Common problems of air pollution:
Various types of severe problems occur due to polluted air. It causes pathological effect on human and affects plants & other living beings.
Table-5: Effect on Human by air pollution
Effect on Human
1.Nitrogen oxidesIt affects the lungs.2.
Causes chest disease, headache, vomiting.
Hydrogen sulphide (H2S)
It causes nausea, irritate eyes and affect throat.
Carbon monoxide (CO)
Oxygen carrying capacity of blood reduces.
It decrease the ability of nerve cells, causes dry throat, indistinct vision, headache etc.
Burning upper respiratory passages.
Coughing, irritation and fatal pulmonary edema.
Irritate nasal and respiratory tracks.
Damage red cells in blood, kidneys and cause jaundice.
Ash, soot, smoke etc.
Cause emphysema, eye irritation and possibly cancer.
Problems that create through Industrial Waste Water Pollution:
Some metal that enters human body through food & water, which create many physical disorders to them. Arsenic, Lead, Mercury, Cadmium, Barium, Chromium, Cobalt, Copper, and Zinc etc does great harm by their poisonous reaction. Here is the brief list of those effects:
Arsenic, which enters to human body through water, disturbs peripheral circulation, mental disturbance, liver cirrhosis, hyperkeratosis, lung cancer, and ulcers in gastro-intestinal tract, kidney damage. Lead causes anemia, vomiting, and loss of appetite, convulsions, damage of liver, brain and kidney. Mercury responsible for abdominal pain, headache, diarrhea, chest pain, hemolytic & some other severe disorder.
Cadmium harms a lot about growth retardation, diarrhea, bone deformation, kidney damage, anemia, and injury of central nervous system, hypertension, injury to lever. Barium causes excessive salivation, vomiting, diarrhea, paralysis, and colic pain.
Cobalt is responsible for diarrhea, low blood pressure, lung irritation, bone deformation, paralysis. Chromium creates gastro intestinal ulceration, diseases in central nervous system, cancer, and nephritis. Damage of liver, kidney and spleen, fever, nervousness, vomiting, low blood pressure, blindness, vomiting, cramps renal damage and other problems create due to zinc and copper poisoning.
Pollution of soil:
Wastes, which pollute soil, that comes to soil from different types of industries such as paper mill, textile mills, iron & steel mills etc. This waste carries variety of chemicals, which are extremely toxic to living beings. They release metallic wastes, oil, greases, plastics heavy metals, solids, and inorganic pollutants in the soil. As a result these poison are transmitted to different organisms in their food chain. When solid waste discharged through sewage system causes several soil and water borne disease. Most of the pathogens are very harmful •to health. Every year millions of organic chemicals are manufactured and its amount is increasing very rapidly.
industries in water and soil.
Thermal Power PlantsHeat, heavy metals, dissolved solids and inorganic compounds.2.
Pulp and Paper
Suspended solids, high or low pH. color, fibres, BOD., COD. high temperature, dissolved substances.3.
Chlorides, suspended and dissolved solids, variable pH and high Bod.4.
Acids, phenols, cyanogens, low pH alkali, lime stone, oils, fine suspended solids, cyanides; cyanates, iron, salts, ores, and coke.5.
Sodium, organic matter, color, high pH and fibres.6.
Acids, alkalies, phenols, tarry or resinous materials and petroleum oils.7.Metal PlatingMetallics, toxic cyanides, cadmium, chromium, zinc, copper, aluminum and low pH.8.
Coal, clay, suspended solids and iron.
Aromatic compounds, acidity and high organic matter.10.Acidslow pH and organic content11.AntibioticsToxic organics and high acidity or alkalinity12.Synthetic drugsHigh suspended and dissolved organic matter including vitamins, high acidity or aldalinity.13.
Calcium, chromium, high salt content, color, dissolved and suspended matter14.
Very high COD, low pH high organic matter, high suspended and dissolved solids containing nitrogen, high potassium.15.
Organic Chemical IndustryToxic compounds, phenols, high acidity, alkalinity. 16.ExplosivesAlcohol, metals, TNT and organic acids 17.FertilizersHigh pH, high ammonia, high flouride content, acidity or alkalinity, organic matter, nitrogen, phosphorus and potassium 18.
Photographic , ProductsOrganic and inorganic reducing agents, silver and alkalies. 19.
Zinc, toxic substances, sulphides and high pH. 20.
High BOD, alkalies, acids, greases, fats, lactose, colloidal solids mainly proteins. 21.
High BOD, high suspended and dissolved organic matter. 22.
Fruits and VegetablesDissolved and colloidal organic matter 23.BeerHigh dissolved solids containing nitrogen and fermented starches and allied products. 24.Soda linksHigh BOD, high pH and high suspended soilds. 25.YeastHigh BOD and high organic matter 26.PicklesHigh suspended solids, color and organic matter. 27.
High suspended solids, dissolved organic matter, proteins and blood
Get Rid of Industrial Waste Pollution
Industries are providing employment, increasing local income, and earning foreign exchange for the country. However, these industries also discharge their waste into the ecosystem which local people depend on for their livelihoods, adversely affecting livelihoods and the day-to-day life of the community. It is a legal requirement in Bangladesh for all red category factories (textile dying and tanning) to establish Effluent Treatment Plants (ETPs). However, there are very few ETPs in the area, and some are “window dressing” as they are either not operated or not operated as they should be due to lack of technical expertise. Because existing laws are poorly enforced, these industries can exploit the surrounding water bodies where they dispose of their untreated waste. In Kaliakoir, industries use Mokosh Beel, the Turag River and the Ratanpur Khal as disposal grounds for their untreated waste. It is estimated that these industries are discharging 30 billon litres of effluent water annually in these water bodies.
Every industry must create some wastes and it should not be stopped but we have to control &. recycle it for the betterment of our future. Prevention of pollution is not so simple. It is impracticable to provide it at reasonable cost. All the growing needs and amenities of modern life are causing pollution. But we have to find some way to prevent & control pollution.
Controlling of water pollution:
Life totally depends on water, so pure polluted free water is the most urgent thing to life. In future people will face serious trouble for not having fine water. That is why we should take appropriate measure to keep water pollution free.
No industrial waste will be directly thrown to water. Every industry there must be waste treatment plant. Recycling technology should apply in every industry.
Every time before establish a new industry must try to use environment friendly equipments and apply latest technology.
Last of all it has to be realized that the world is our own territory. So, we must keep it pollution free for the betterment of our future generation.
|Pic-9 Effluent Treatment Plant (ETP||Pic-10 Textile dyeing process|
[Source: MACH (Management of Aquatic Ecosystems through Community Husbandry) is a Government of Bangladesh project supported by USAID].
Prevent soil from Industrial Waste Pollution:
Disposal of wastes is very essential. Wastes should be recycled & reused which is very essential. The following procedures can reduce waste worries
(a) Industrial Wastes should be collected in proper ways.
(b)Disposal of Wastes is more economical, so it must be done.
(c) No toxic material use to kill pesticides,
We have to take some other measures to prevent soil from industrial waste pollution. Unwanted materials must dump in proper ways. In we must try to use natural fertilizers. We should stop using of all types of fire weapons. Use of all types toxic chemicals need to ban. Tree plantation is a must for a better pollution free environment. Recycling and re-use of waste can ensure to keep natural environment in proper position.
Findings and Recommendations
Through this work I have got the following points that are very important.
Air, water and soil, which are the three basic elements for
living beings are polluting through industrial waste,
The soil we use to grow food is severely polluted. ;;
High concentrations of heavy metals such as chromium were also found in sediments near the industries.
Water quality has deteriorated to a level which is detrimental to fish and other aquatic life requiring oxygen. This has reduced the availability of fish, fodder and other wetland products and services which local people have for generations depended on.
Public water bodies are failing to meet national water quality standards, threatening the livelihoods of those dependent on wetland products and biodiversity, and this is a direct consequence of the failure of factories to meet the same national standards in their waste water.
The number of industries is increasing rapidly without consideration of the local impact on livelihoods from natural resources. There is no zoning policy or local development planning.
The air polluted with dust, smoke and several gases.
Water is contaminated with chemical and toxic metal.
Solid industrial wastes cause water logging.
Some Industries are creating pesticides.
Disposal of Industrial wastes is the major problem for soil pollution.
The pollutants affect and alter the chemical and biological properties of soil.
Water pollution is now become a global problem.
Splitting of atom bombs create waste management problems.
Radioactive pollution is responsible for some cancer.
Toxic materials cause various types of severe diseases.
Nuclear waste from reactors poses serious thermal pollution problems.
Toxic Gases deplete ozone layer.
10% decrease of ozone gas increase cancer up to 20%-30%.
Most wastes are recycling able.
Prevention of pollution and controlling of waste is possible.
Metal that enters human body through food and water create physical disorder.
Increased awareness among industrialists about the pollution problem and their legal and social responsibility to prevent it.
It should be mandatory for all textile and dyeing industries to adopt more efficient production options.
It should be mandatory that industries construct and then regularly and efficiently operate their ETPs and monitor their effluents to keep them within the standards set by law.
Voluntary or public provision of common ETPs may be a solution to serve adjacent small scale industries, operating on a cost sharing basis.
National and community level bodies should be established and validated to monitor water quality of khals, beels and rivers, and the results used to determine anti-pollution measures, operating permits and actions (including legal actions) against offending industries.
International buyers have a key role in influencing industry, they need to be influenced to adopt environmental codes of conduct and then to enforce them on their supplying industries.
Bangladesh trade bodies should change their role and set environmental conditions on membership, for example they could cancel membership of companies that fail to install and operate properly ETPs.
Unplanned industrialization needs to stop.
Solid & other wastes should be recycled.
All types of nuclear explosion must be stopped.
Use of CFC, CO and other toxic gases need to be controlled.
For sustainable development industrialization will proceed in proper way.
We should follow the international agreement for industrialization.
Modern society is itself polluted through its developing process. Thus this pollution circle also affects every member of environment & human beings. Environment is now in danger and we not safe enough. But we have the ability to keep our environment free from all kinds of disturbance. At present not only developed countries but also developing countries are responsible for pollution through industrialization. Developed countries should initiate several programs against pollution and we must go with them for a better world to survive & for betterment of our future generation.
01. Document: Environmental Protection Agency, Solving the Hazardous Waste Problem: EPA’s RCRA Program (Washington, DC: EPA, November 1986)
02. Sharma, B. K. Industrial Chemistry, Eighth Edition, Goel Publishing House, Meerut, India, 2004.
03. Chowdhury, N. S. and Clemett, A. E. V. (2006) Industrial pollution and its threat to Mokesh Beel wetland in Kaliakoir. MACH technical report, Dhaka. Government of Bangladesh (1997), Government of Bangladesh, Dhaka.
04. Ullah, A. N. Z., Clemett, A. E. V., Chowdhury, N., Huq, T., Sultana, R., and Chadwick, M. T. (2006) .The Bangladesh Environmental Conservation Rules 1997. Human Health and Industrial Pollution in Bangladesh, Stockholm Environment Institute,
05. Recycling industry reduces waste Harri Makela, Freelance Journalist Published by Ministry for Foreign Affairs of Finland
01. Sharma, B.K., Industrial Chemistry, Eighth Edition, Goel Publishing House, Meerut, India, 2004.
02. Philip Gain, Bangladesh Environment: Facing the 21st Century, SEND.