With the advent of winter season when dust remains in the atmosphere as rains are sparse, Dhaka's air pollution level is getting worse by the day. This is evident as per a recent new study that found the megacity's air pollutants more than five times higher than the World Health Organisation's recommended standard.
However, the study led by Shakhaoat Hossain, Associate Professor at the Department of Public Health and Informatics of Jahangirnagar University, mainly focused on severe risks posed by indoor air pollution in Dhaka. This was because until now much attention has been given on outdoor air pollution, ignoring serious dangers induced by the indoor air pollution within homes.
The results of the study, published in the Indoor Environments journal, measured the levels of fine particulate matter (PM2.5) in 43 households across Dhaka. But the average PM2.5 level recorded was 75.69 micrograms per cubic meter, far exceeding the WHO standard of 15 micrograms per cubic meter. This pollution levels surpassed 200 micrograms per cubic meter, indicating a severe indoor air quality issue in many homes.
What are the main reasons for such indoor air pollution in Dhaka? The key contributors, as identified by the study, included chemicals generated from tire friction during road traffic, the burning of plastic in landfills and the use of unrefined oil in cooking. These sources release toxic substances that severely harm air quality both indoors and outdoors.
Women and children are the most affected by the indoor air pollution as they stay long hours at homes. Besides, people in general spend 60-65% of their time indoors. As a result, air pollution in Bangladesh both at homes and outside the homes has become the deadliest environmental concern with hundreds of thousands of people dying of this reason every year. According to an estimate, air pollution annually claims over 235,000 lives in Bangladesh.
In Dhaka and elsewhere in the urban areas of Bangladesh, air pollution increasingly raises the risks of breathing difficulties, cough, lower respiratory tract infections, as well as depression and other health risks.
Like indoor, outdoor air pollution in the capital has also deteriorated. The major sources of outdoor air pollution are brick kilns, surface dust and sand, vehicle emissions, industrial pollution and large-scale construction activities.
Heavy traffic causes the highest level of air pollution in Dhaka. This is because the number of different types of vehicles like passenger buses, trucks, jeeps, minivans, auto rickshaws and other kinds of motorized transport modes have increased manifold in the last two decades.
Another major polluter is brick kilns. There are over 2,000 brick kilns in and around Dhaka and about 5,200 more spread all around the country. These brick kilns burn coal to create bricks for our booming construction industry.
With rapid urbanization, Bangladesh has seen an increase in construction activities. As a result, extensive unplanned residential development and large projects to build bridges, highways and mass rapid transit create large amounts of resuspended dust.
With people increasingly becoming vulnerable to air pollution, both indoor and outdoor, this is high time for the government and the general public as well to wake up to the this serious crisis.
