Environmental Pollutions in Dhaka City, 2010

Environmental Pollution
In
Dhaka City

Environmental pollution is as old as the civilization itself. It has become a major concern in the last few decades. It is the byproduct of the development of civilization and in fact a price for the progress. The present environmental condition of Bangladesh is not at all equilibrium. Severe air, water and noise pollution are threatening human health, ecosystems and economic growth of Bangladesh.
Air pollution caused due to increasing population, burning fossil fuels, industrialization and associated motorization. The water resource of Bangladesh becomes a major health hazard due to arsenic contamination, inadequate solid waste and industrial effluent management. The inhabitants of major cities of Bangladesh are also exposed to high level of noise pollution. Environmental degradation of Bangladesh is also caused due to poverty, over-population and lack of awareness on the subject. It is manifested by deforestation, destruction of wetlands, soil erosion and natural calamities.
DIFFERENT ASPECTS OF ENVIRONMENTAL POLLUTION:
Air Pollution
Air pollution is a serious environmental health hazard affecting the populations of Bangladesh. Air pollution of Dhaka is caused due to increasing population and associated motorization. Indoor air pollution is mainly associated with the use of biomass fuels during cooking with poor ventilation. Industrial emissions and automobiles are the principle sources of outdoor air pollution. The amount of pollutants in the air of Dhaka city is shown below:
Location Sulfur Dioxide Nitrogen Dioxide Carbon Monoxide Suspended Particular Matter
Concentration (µg/m3) Permissible (µg/m3) Concentration (µg/m3) Permissible (µg/m3) Concentration (µg/m3) Permissible (µg/m3) Concentration (µg/m3) Permissible (µg/m3)
Gulistan 800 100 500 100 33200 5000 1332 400
Jatrabari 1300 500 67000 4667 Panthopath 900 500 85100 2666 Mohakhali 1200 500 69300 2111 Source: Department of Environment (DOE), 1997
Sources;
Burning of Fossil Fuel: Pollution mainly occurs due to burning of fossil fuels like coal, petroleum etc and associated black smoke. Over 99% of the brick kilns use fossil fuel but don’t comply with the “Brick Kiln Ordinance” and pollute enormous air.
Industrial Discharge: Industries cause air pollution through smoke emission. Agro based industries like sugar, pulp, paper, tanneries; and value added industries like textile, garments, pharmaceutics, oil refineries, fertilizer and chemical industries are the major contributors for air pollution.
Emission from Vehicles: One of the major sources of air pollution in urban areas of Bangladesh is due to the unburned fuel from two stroke engine vehicles. Dhaka has been rated as one of the most polluted cities of the world. Bangladesh Atomic Energy Commission reports that automobiles in Dhaka emit 100 kg lead, 3.5 tons SPM, 1.5 tons SO2, 14 tons HC and 60 tons CO in every day.
Effects;
Severe environmental pollution is threatening human health and economic growth of Bangladesh. Air pollution mostly affects the urban children. Indoor air pollution is a greater threat to health than outdoor air pollution. Bangladesh could avoid 10,000 deaths and save between 200 and 500 million dollars a year if indoor air pollution in four major cities can be reduced to acceptable limits.
Immediate effect of smoke inhalation causes headache, vertigo, burning sensation of the eyes, sneezing, nausea, tiredness, cough etc. Its long term effect may cause asthma and bronchitis. Lead affects the circulatory, nervous and reproductive systems as well as affects kidney and liver including liver cancer or cirrhosis. Carbon monoxide hampers the growth and mental development of an expected baby. Nitrogen oxides cause bronchitis and pneumonia.
Water Pollution
Water pollution creates serious health hazard for Bangladesh. The dumping of municipal wastes, hospital wastes and toxic environmental discharges from mostly industries pollute both surface and ground water sources. The most dangerous threat emanating from environmental degradation is the arsenic contamination of ground water.
Sources;
Industrial Waste and Effluent: The main industrial areas of Bangladesh are at Dhaka, Chittagong, Khulna, and Bogra districts. The mostly contributing industries for water pollution are pulp and paper, pharmaceuticals, metal processing, food industry, fertilizer, pesticides, dyeing and painting, textile, tannery etc. More than 200 rivers of Bangladesh directly or indirectly receive a large quantity of untreated industrial wastes and effluent. Everyday approximately 700 tanneries of Dhaka city are discharging about 16,000 cubic meters of toxic wastes. The Department of Environment (DOE) has listed 1,176 factories that cause pollution throughout the country.
Solid Waste and Sewage Disposal: The indiscriminate discharge of solid waste, domestic and hospital sewage are the major source of water pollution in Bangladesh. About 4,000 to 4,500 tons of solid wastes are generated daily and only half of the generated wastes are disposed of in low lying areas or into river water. These solid wastes are associated with the problems of littering on roads, spilling around the bins, clogging of drains, indiscriminate dumping on vacant plots and cause serious environmental pollution. More than 500 hospitals and clinics of Dhaka city generate and release hazardous and toxic wastes without any treatment.
Inadequate Sanitary Facilities: Inadequate sanitation facilities pose a serious environmental threat in Bangladesh. Dhaka Water and Sewerage Authority (DWASA) can serve only for 15 to 20% of city population. In absence of the sanitation and infrastructural services, 40% having septic tank and soak pit, 15% using pit latrines and 30% using open latrines. The sewage is mostly released into low-lying areas and river water in untreated manner causing great environmental hazards.
Arsenic Contamination of Ground Water: Arsenic in ground water poses a serious environmental hazard for Bangladesh. About ninety-seven percentages (97%) of Bangladesh people have been using ground water as the main source of drinking water but the water has been threatened by arsenic contamination. More than half (52%) of the studied population drink well-water containing >50ug/L of arsenic and more than two-thirds (70%) drink well-water containing >10ug/L of arsenic. The acceptable level of arsenic in drinking water is 0.05 mg/L for Bangladesh but some places it is found more than 70 times higher than that standard. About 80 million people are at a risk of arsenic contamination.
Effects;
Industrial emissions cause different waterborne disease and damage to health slowly and cumulatively. It causes melanosis, kurtosis and conjunctivitis. Subsequently respiratory problem, gangrene, skin, kidney and lung cancer would arise. The inadequate sanitation facilities also pose a serious threat to health.
Noise Pollution
The noise pollution is second major health hazard in Bangladesh. According to World Health Organization (WHO), 60 decibel (DB) sound can make a man deaf temporarily and 100 DB sound can cause complete deafness. According to the Department of Environment (DOE), the perfect sound condition for Bangladesh is 50 dB for the daytime and 40 dB for the night in residential areas and 45 dB for the daytime and 35 dB for the night in peaceful areas. At present noise level in Dhaka city are estimated ranging from 60 to 100 decibel. If present situation continues then by the year 2017, 50% people of Dhaka city will loss 30 decibel of hearing power. The daily variation of noise level near the road at some of the key locations of Dhaka city is shown below:
Location 7am-11am 11am-3pm 3pm-7pm 7pm-1am
Gulshan (Comercial) 80.08 79.34 81.13 78.52
Science Lab (Mixed) 76.24 75.19 77.23 75.32
Saydabad (Comercial) 83.27 83.89 84.37 82.08
Farmgate (Comercial) 80.07 78.86 81.96 8.28
Danmondi (Residential) 75.87 74.38 75.21 76.30
Uttara (Residential) 76.25 74.81 76.81 73.36
Gulshan (Residential) 76.16 74.83 76.11 74.31
Source: Nazmul Chowdhury research on noise pollution in Dhaka city on Feb 2002
Sources;
The main sources are industries, motorized vehicles, hydraulic horns, aircrafts, railway vehicles, construction works and indiscriminate use of loudspeaker.
Effects;
Noise pollution causes mental and physical illness among the people. Sound pollution causes deafness to heart attack. Any sort of noise pollution seriously affects expecting mothers. It also causes high blood pressure, tachycardia, headache, indigestion, and peptic ulcer.
Land/Soil Pollution
Though the land/soil pollution causes mainly in rural areas but because of many reasons it is also resulting in urban areas now. It has examined that resulting of soil degradation; earthquake, erosion, bad soiling for construction etc. increase more and more in Dhaka city day by day.
Sources;
Deforestation: Deforestation for agriculture production, urbanization and other purposes comes after next. Plants are responsible for holding the soil together firmly so, when the plants can’t grow the soil splits, leading to soil erosion.
Contamination by industrial waste: Soil contamination occurs when chemicals are released by spill or underground leakage. Among the most significant soil contaminants are hydrocarbons, heavy metals, MTBE and chlorinated hydrocarbons.
Plastic and non-decomposed objects: In big cities, it is very difficult to control human or household wastages without maintaining proper waste management. A huge portion of those wastages are non-decomposed objects, in other words plastic, which causes not only soil pollution, drainage obstruction, water pollution and also air pollution in process of recycling.
Effects;
Soil pollution causes soil degradation, soil erosion and also firm crust layer of earth which deteriorate the soil for either of both construction for commercial/residential high-rise structure or any other agricultural/non-agricultural production.
Light Pollution
Another hazarded pollution in Bangladesh is light pollution; which occurs due to prominent excess illumination of an area. It is largely visible in Dhaka, on advertising boards and billboards, in sports or entertainment events at the night. In residential areas the lives of the inhabitants is greatly affected by this. It also affects the astronomical observations and activities by making the stars almost invisible.
Sources;
Mainly advertising boards and billboards, sports or entertainment events at the night or indoor, excessive use of streetlight, high powered security light, headlights of vehicles etc. are the major sources.
Effects;
Light Pollution causes excessive light on the retina causes extreme discomfort in the eyes, especially in dim conditions like during night time. Bright lights strain the eyes and also give headaches and migraines.
Other than these listings above, some inconsequential pollutions in Dhaka city are;
"Thermal/Heat Pollution" due to excessive use of coolers in residents, industries and vehicles, defective transports, unnecessary use of electrical equipments in daylight etc.
Thermal pollution due to carbon-dioxide causes skin diseases, blindness and many other life threatening diseases like cancer or tumor.
"Littering" causes by throwing of inappropriate man-made objects, un-removed, onto public and private properties etc.
Decomposed objects pollute air and non-decomposed objects obstacle drainages, pollute surroundings, horde diseases and help bugs to spread etc.
Many people died every year in many diseases due to environmental pollution. The death rate mainly due to environmental pollution is shown below:
Cause of Death Death in all Ages (%) Death in Infant (less than one year ages) (%)
National Level Dhaka City National Level Dhaka City
Cardiovascular 7.87 17.5 4.77 6.5
Asthma 5.2 4.3 1.87 2.8
Diarrhea 1.66 7.8 18.96 17.5
Cancer 4.05 5.3 4.05 5.0
Dysentery 4.05 5.5 1.66 3.9
Viral Hepatitis 2.14 3.4 2.14 3.4
Source: Bangladesh Bureau of Statistics (BBS), Statistical Yearbook of Bangladesh 2001
Environmental issues have become major concerns due to impact on public health and development of Bangladesh. Air and water pollution, groundwater contamination, nuisance from solid wastes and noise pollution are the main environmental pollutions of Bangladesh. Dhaka City is one of the most polluted cities in the world. Environmental problems occur mainly due to population growth, urbanization, industrialization, rapid rise in transportation, inadequate and improper traffic management, poor sanitation systems and inefficient solid waste management.
It is a serious but neglected issue throughout Bangladesh. Government as well as other organizations must take adequate steps to reduce the environmental pollution as well as to improve the environmental degradation and pollution control for our own existence.