Home | blog

Air Pollution in Dhaka City: A Burning Issue Md. Saiful Islam

Lecturer, Department of Microbiology, Shaheed Suhrawardy Medical College, Sher-E-Bangla Nagar, Dhaka-1207, Bangladesh; Email: saifulaa@yahoo.com; Cell no.: +8801971106875

Air pollution is one of a variety of manmade environmental problem. Air pollution may be defined as an

atmospheric condition in which various substances are present at concentrations high enough above their

normal ambient levels to produce a measurable effect on people, animals, vegetation or materials.

‘Substances’ refers to any natural or manmade chemical elements or compounds capable of being airborne.

These may exist in the atmosphere as gases, liquid drops, or solid particles. It includes any substance

whether noxious or benign; however, the term ‘measurable effect’ generally restricts attention to those

substances that cause undesirable effects. Air quality has deteriorated both due to human activities, and

natural phenomenon such as wind-blown dust particles etc. There are two major sources of air pollution in

Bangladesh, vehicular emissions and industrial emissions. Recently, air pollution has received priority

among environmental issues in Asia, as well as in other parts of the world. Dhaka is a major cultural and

manufacturing center. The common types of industries in and around the periphery of Dhaka are ready-made

garment manufacturing, jute, tanneries, textile, tea processing, fertilizer, cement, paper and pulp, chemicals

and pesticides, food and sugar, pharmaceuticals, petroleum refinery, distillery, rubber, plastics, and brick

manufacturing, assembling buses, trucks, and motorcycles, assembling radios and televisions. Air of Dhaka

is being polluted day by day very badly. The other urban areas i.e. Chittagong, Khulna, Bogra and Rajshahi

have much lesser health problem related to urban air pollution.

Contamination in the atmosphere caused by the discharge, accidental or deliberates 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 eco system through acid rain. Dhaka is fast turning into an inhabitable city. Dhaka city

air reported to containing higher proportion of lead and carbon monooxoid (CO) must be considered very

alarming. Air pollution has become a matter of great concern for us in recent years. Those who are living in

cities in Asian countries including Dhaka have already realized how seriously air pollution has been

poisoning life and degrading the environment. Faulty vehicles, especially diesel run vehicles, brick kilns,

and dust from roads and construction sites and toxic fumes from industries contribute to air pollution.

Industrialization and mechanized vehicles are two major sources of air pollution in our country. Those are

unavoidable accompaniments of increased economic activity of any country. The number of automobiles has

been increasing in Dhaka city at the rate of at least 10 to 20% annually, which has been contributing to air

pollution on the one hand and traffic congestion on the other.

The International Atomic Energy Agency (IAEA) stated in its News Briefs that pollution levels of lead in

Bangladesh are among the world’s highest during dry season, according to Bangladesh Atomic Energy

Commission (BAEC), with levels falling during periods of medium and heavy rainfall. The volume of

poisonous particles in the city air has reached far beyond the permissible level for human body in recent

years. The Dhaka city dwellers are always at a serious health risk due to the highly polluted air, warned

health experts. The increasingly high concentration of toxic elements in the air is causing a foggy blanket in

the city sky at present. The website reveals that the air quality of the city is lethal for human body especially

during winter and post winter. According to the website, poisonous carbon monoxide, sulphur dioxide,

nitrogen dioxide, suspended particulate matter (PM-10) and particulate matter (PM-2.5) exist in Dhaka's

air beyond permissible level for human body. Due to increase of PM-10 and PM-2.5, people lose lung

function and suffer from chronic respiratory and cardiovascular diseases while nitrogen dioxide increaseAir Pollution in Dhaka City: A Burning Issue Islam MS

21

risks of bronchitis and pneumonia. Nitrogen dioxide causes respiratory infection. Carbon monoxide reduces

delivery of oxygen into the human body, creates severe headache and decreases visual perception and

manual dexterity. Around 75% of the ingested lead is deposited in bones and tissues causing irreversible

brain and kidney damage. Growing nervous system of young children is particularly vulnerable.

Bangladesh has yet to be implemented a National Air Quality Standard, there are no detail air quality

regulations based on which Environmental Impact Assessment could be done. Very few works have been

done on air quality measurements and national air pollutants estimates in Bangladesh. Government should

strengthen vehicle emission standards, regulations and enforcement. Measures to reduce fuel demand and

improve traffic conditions are also critical to ensuring a net emission reduction and should be used as a

complement to technical measures.

References

Bangladesh studies pollution levels. IAEA News briefs. Volume 11, No. 4(73), November/December 1996:

11

[Journal of Science Foundation 2014;12(2):20-21]