Dhaka experiences worst air quality


Directorate of Environment (DoE) has issued a public warning notice on air pollution as the air quality of Dhaka has been ranked the worst in the Air Quality Index (AQI) over the past week. A public warning notice by DoE on November 20 states that the particulate matters coming from road dust and soil dust, vehicles, burning of biomass, orthodox brick kilns around and inside the capital are responsible for air pollution in Dhaka.

On November 21, Dhaka’s air quality measured 193 AQI which is considered unhealthy and on November 19, it measured 252 AQI, which is considered as extremely unhealthy according to the standards for Bangladesh (NAAQS). The air quality is categorized as good when the AQI score remains between 0-50 while the air is moderate when score is 51-100. When the number is between 101 and 150, the air is classified as unhealthy for sensitive groups.

When the AQI value is between 201 and 300, every city dweller may begin to experience health effects, the report said. According to international research, air pollution is the 3rd major cause of death in Bangladesh mostly from chest diseases. The United States based research organization Health Effects Institute (HEI) and the Institute for Health Metrics and Evaluation (IHME) publish reports on air quality every year. According to the recent report, about 1 lakh and 23 thousand people had died in Bangladesh due to air pollution in 2017; which is 14 percent of total death.

Besides, average life expectancy of Bangladeshi people has decreased by 1 year and 10 months, which is highest life expectancy reducing rate in the world. Children, adults, and people with respiratory diseases are advised to avoid outdoor exertion while everyone else is suggested to limit outdoor exertion in this situation.

The AQI, an index for reporting daily air quality, tells people how clean or polluted the air of a certain city is, and what associated health effects might be a concern for them. Bangladesh’s overcrowded capital has been grappling with air pollution for a long time. The quality usually improves during monsoon.

Public Health Expert Dr Lelin Chowdhury told Bangladesh Post, “Air pollution is one of the major reasons behind respiratory diseases like Asthma, chronic obstructive pulmonary disease or COPD, Bronchitis, Bronchiectasis, lower respiratory infection and even lung cancer.” He also said, “The number of Asthma patients has been increasing day by day due to dust and air pollution. The air pollution also worsens the intensity of respiratory problems by working as irritants for those who are already suffering from these diseases.”

About the recent air pollution, Chairman of Save the Environment Movement [Poribesh Bachao Andolon (POBA)] Abu Naser Khan told Bangladesh Post, “Gaseous and particulate matters are responsible for the air pollution. Gaseous pollutants like Carbon Di-oxide (CO2), Carbon Monoxide (CO), Sulphur Dioxide (SO2), Nitrogen Oxide (NOx) and other hazardous gas has mixed with the air of Dhaka city in alarming quantity. Besides, particulate matters [sizes between 2.5 to 10 microns of diameter] are mixed with air due to dust.” Small particulate pollutants [2.5 microns] can enter deep inside the lung and create respiratory diseases, he added.

According to the WHO, continuous exposure to such particles increases the risks of developing cardiovascular and respiratory diseases and even cancer in the lung and the urinary tract or bladder in human body. In this situation, DoE suggested applying modern techniques for cleaning up the city roads, using good quality mobile and air filter in vehicles, using dust collector at industries, spraying water to stop dust from spreading during construction works and keeping construction materials and sites under cover with the enforcement of law and proper monitoring.

The DoE also suggested proper maintaining of ‘Brick Manufacturing and Brick Kiln Establishment (Control) Act 2013 (revised 2019)’ to check pollution by brick kilns.