Mst. Srabony Sultana Bristy : Today, there is a lot of discussion about air pollution. Air pollution refers to the presence of harmful substances, such as gases, particulate matter, and pollutants, in the air in concentrations that can have adverse effects on human health, the environment, and ecosystems. It is a major environmental risk. Due to rapid population growth, increasing of industries, rapid and uncontrolled development socio-economic changes, traffic congestion the air quality of Bangladesh has been termed as hazardous.
Air pollutants derives from various sources such as burning of fossil fuels (vehicles, road construction, building construction) agricultural activities (application of fertilizers, burning of crop stubble) exhaust from industries and factories (bad smoke, waste).The major air pollutants in Bangladesh are Particulate Matter(PM), leaded fuel, NO2 and SO2. Particulate Matters are emitted from construction sites, unpaved roads, fields, fires.NO2 and SO2 emitted from power plants, industries and automobiles.
According to World air Quality Index (AQI) 2022 report, Bangladesh ranked 5th worst polluted country and TBS report in 2022, showed that the most polluted area in Bangladesh is Gazipur. Next to Gazipur are the neighboring districts of Dhaka (2nd) and Narayanganj(3rd). Road digging, renovation works, mega projects, nearby brick kilns, thousands of small and large industries, burning of garbage are observed as one of the main causes of these three cities. The WHO AQGs 2021 recommend annual mean concentration of PM2.5 not exceeding 5 microgram per cubic meter and NO2 not exceeding 10 microgram per cubic meter and the peak season mean 8-h O3 concentration not exceeding 60 microgram per cubic meter. In Bangladesh the standard for pollutants are NO2(0.053 ppm), SO2(0.03 ppm), O3(0.08 ppm for 8-h).The amount of pollutants in the air of the three most polluted cities is about 4-5 times higher than the standard in Bangladesh.
Air pollution and human health: Air pollution have major impacts on human health. It can lead to a wide range of diseases including trachea, bronchia and lung cancers, stroke, aggravated asthma, respiratory infections. According to ESPO by 2019 report, 200,000 people in Bangladesh could die because of respiratory diseases and long term exposure to high concentration of air pollution. Research published by Science Advances estimated 24,000 people in Dhaka died prematurely due to air pollution between 2005 and 2018. Air pollution also affects mental health. The report titled “Air Quality and Health in Cities” said yearly average of PM2.5 is 71.4 microgram per cubic meter in Dhaka and yearly average of NO2 is 23.6 microgram per cubic meter. According to World Bank, One percent increase in exposure to PM2.5 above the WHO AQG is associated with a 20 percent higher probability of being depressed. Children under five years, elderly, and people with comorbidities such as diabetes, heart or respiratory conditions are most vulnerable says World Bank Report launched in 2022.
Economic effects of air pollution: Poor air quality has a great connection to a vast array of economic costs. Air pollution damaged property by metallic corrosion of SO2 which converted to Sulphuricacid. Deposition of this acid on metal parts of building roofs, railway tracks, bridges cause enormous loss. Air pollution also damages the agricultural productivity and can reduce food supply. As a result, this can increase food prices and decrease food security. Polluted air can damage ecosystem (both aquatic and terrestrial), reduce workforce productivity by work absences, physical and mental health issues. According to World Bank Report, Air pollution costs Bangladesh up to 4.4 percent of its GDP in 2019. According to, Greenpeace Southeast Asia and Center for Research on Energy and Clean Air 2023 report shows, Bangladesh losses 14 billion dollar a year due to air pollution.
Air pollution and climate change: Emissions of pollutants into the air can result in changes to the climate and greenhouse gases such as CO2, CO, CH4 are often referred to as climate forces. These pollutants warm the climate and decrease rainfall. Burning of fossil fuels, mass deforestation lead to the increase of CO2 emissions which traps heat inside the atmosphere and components of PM warms climate. In Bangladesh climate change affects many sectors including agricultural, human health, biodiversity loss, sea level rise. Due to climate change the country experienced small to medium scale flood, cyclone. According to World Bank report, average tropical cyclones cost Bangladesh about 1 billion dollar annually. By 2050, one third of agricultural GDP may be lost due to climate variability and extreme events. By sea level rising the coastal area people will affected by coastal flood.
Increasing the public’s awareness concerning reducing emissions, air quality improvement, and environmental protection might be a great start. We have to use bio fuels or natural gas which is environment friendly and stop burning fossils which releases harmful gases. By using alternatives of fossil fuel such as solar energy, geothermal energy can save the environment. Finally, environment protection laws should be made effective and those who violate laws should be punished.
The writer is a student of the Department of Geography and Environmental Science of Begum Rokeya University, Rangpur.
