Air Pollution in Dhaka City
Kabir Golam
Corporate Quality Assurance Department
Sunoco Inc.
Philadelphia, USA
Member BEN CC
Abstract
This paper presents the level of air pollution in Dhaka City. The air of Dhaka City is regularly being
polluted by motor vehicle emissions, small industries, dumping of solid waste, brick burning and tanneries.
As per the guidelines of the World Health Organization, the maximum allowable airborne particulate
matter is 150 microgram per cubic meter. But according to the Department of Environment, the density of
airborne particulate matter reaches 463 microgram per cubic meter during dry season in Dhaka. Frequent
exposure to high level of air pollution is causing serious damage to the health of inhabitants.
Introduction
The paper aims at studying the level and causes of air pollution in Dhaka City and analyzing its level of
severity. The department of Environment Protection of Bangladesh with aid from World Bank carried out
a research project on air pollution in Dhaka City in 2008 (Air Quality Management Project, Department of
Environment, GOB). The results of this research project are very alarming. Dhaka is considered to be one
of the worst polluted cities in the world. As per the study, about 15,000 people die every year due to
polluted air and 6.5 million fall sick. Realizing the severity of the issue, the government should take
appropriate measures to control air pollution.
Causes for air pollution
1. Motor vehicle emission is the major cause for air pollution around Dhaka.
As per Bangladesh Road Transport Authority law, trucks, buses and minibuses that are older than 10 years
are not allowed to be driven in the city limit. However, BRTA estimates that there are presently 13,778
such buses and trucks plying the streets of the capital out of 5,62,851 registered vehicles while 80,615,
including private car, bus and trucks, have no fitness certificates. (http://tazakhobor.com/bangladeshi-newsviews/1-bangladeshi-news-views/454-brta-old-vehicles-crackdown)
According to a report published by International Fuel Quality Center, the sulfur level in diesel sold in
Bangladesh is well over 1000 PPM, whereas sulfur level in diesel sold in the USA is 15 PPM (The
appendix shows the sulfur in diesel for various countries). Most of the sulfur in fossil fuel is converted to
sulfur dioxide, but a small amount is also converted to sulfuric acid. In the atmosphere, gaseous sulfur
dioxide can also be converted to sulfuric acid and sulfate-containing particles. Thus, atmospheric
concentrations of sulfur dioxide are often highly associated with acidic particles, sulfuric acid particles and
sulfate particle concentrations. Sulfur dioxide is a very water-soluble gas; and therefore, most of the sulfur
dioxide that is inhaled is absorbed in the upper respiratory tract and does not reach the lung's airways.
However, the small amount of sulfur dioxide that does penetrate into the airways can provoke important
health effects, primarily in individuals with asthma. Burning fuel with higher level of nitrogen yields toxic
nitrous oxides.
Motor vehicle emissions are throwing about 4 thousand tons of fine particles into the atmosphere of Dhaka
City every year causing serious health effects (Mehedi Hasan, Daily Ittefaq August 18, 2010)
Motor vehicle emission is also the major cause for green house gases around Dhaka.
Gases that trap heat in the atmosphere are often called greenhouse gases. The principal greenhouse gases
that enter the atmosphere because of human activities are:
Carbon Dioxide (CO2): Carbon dioxide enters the atmosphere through the burning of fossil fuels (oil,
natural gas, and coal), solid waste, trees and wood products, and also as a result of other chemical reactions
and industrial emissions. At the same time carbon dioxide is also removed from the atmosphere when it is
absorbed by plants as part of the biological carbon cycle.
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Methane (CH4): Methane is emitted during the production and transport of coal, natural gas, and oil.
Methane emissions also result from livestock and other agricultural practices and by the decay of organic
waste in municipal solid waste landfills.
Nitrous Oxide (N2O): Nitrous oxide is emitted during agricultural and industrial activities, as well as during
combustion of fossil fuels and solid waste.
Fluorinated Gases: Hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride are synthetic, powerful
greenhouse gases that are emitted from a variety of industrial processes.
2. The other major source of toxic gases in Dhaka is burning bricks in and around the city. Very low quality
coal with high sulfur content is used to burn bricks in the open atmosphere resulting in large amount of
toxic gas production. Modern closed burning system can be adopted for brick production to reduce air
pollution in Dhaka.
Source: Impact Analysis of Brick kilns on the Air Quality in Dhaka, Bangladesh.
Dr. Sarath Guttikunda, May 2009
3. There are many industries in and around Dhaka polluting the air. Though there is a law to control
industrial emissions, it is not enforced. So, toxic gases are thrown into the air in and around Dhaka through
these industries.
4. Municipal waste is dumped at various spots around the city in open areas. This waste generates toxic
gases like carbon dioxide, methane and nitrous oxide.
5. There are still many open toilets in and around the city producing gases like methane and nitrous oxide.
6. Reduced watershed around the Dhaka city is a factor for increased carbon dioxide, because water body
reduces carbon dioxide through absorption.
7. We have seen deforestation around Dhaka City through housing construction and other developments
that is one of the contributing factors for air pollution.
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Control of air pollution
The approaches to combat air pollution can be divided into three categories: source control, enforcement of
regulations and public awareness building.
Source Control:
1. Reduction of sulfur content in diesel would be a major step in source control.
2. Installation of catalytic converter in all types of vehicles would reduce toxic emissions.
3. Reduction of nitrogen in diesel and gasoline would help reduce NO2
4. Developing mass transit system would help reduce motor vehicles in Dhaka.
5. Modern closed burning system can be adopted for brick production.
6. Modern closed waste management system needs to be adopted for municipal waste.
7. The toxic waste from industries can be controlled through installation of scrubbers.
8. The dust from numerous construction sites should be controlled with spraying of water.
9. In an effort to comply with increasingly stringent diesel exhaust emissions standards, diesel engine
manufacturers have invented a technology known as selective catalytic reduction (SCR)-a method of
converting harmful diesel oxides of nitrogen emissions, by catalytic reaction, into nitrogen gas and water.
Enforcement of regulations:
1. Regulation of removing older buses and trucks should be enforced.
2. All motor vehicles should be inspected yearly for emissions.
3. No motor vehicle should be allowed without fitness certificate.
4. Number of private cars should be regulated.
5. Use of cleaner fuel should be mandatory.
6. Regulation for controlling construction dust should be developed.
7. Regulation for controlling toxic industrial emission should be strictly enforced.
8. Law of conservation of water bodies needs to be enforced.
9. Uncontrolled dumping of municipal waste should be punishable offence.
10. Tree preservation law should be enforced.
Public Awareness Building:
1. Media can play a vital role in building public awareness of the severe health effects of air pollution.
2. Health care professionals can build public awareness through seminars and talk shows.
3. People need to be educated of adverse effects of dumping waste.
4. Adverse effects of open toilet should be communicated to general poor people.
Conclusion
The level of air pollution in Dhaka City far exceeds the acceptable limits. This has serious implication on
the health of the inhabitants of the city. It is observed that the pollution level is closely related to number of
motor vehicles, quality of fuel, industrial waste, municipal waste, burning of brick, construction and open
toilets. Urgent measures should be taken to reduce the level of air pollution in Dhaka City.
References
Daily Ittefaq Aug 18, 2010 (Mehedi Hasan, Severe Air Pollution in the capital)
Study by Environmental Protection Department of Bangladesh 2008 (Air Quality Management Project,
Department of Environment, GOB)
International Fuel quality center report 2008 (www.ifqc.org)
Impact Analysis of Brick kilns on the Air Quality in Dhaka, Bangladesh.
Dr. Sarath Guttikunda, May, 2009
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Source: International Fuel Quality Centre (www.ifqc.org)
Appendix: 1
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