Bangladesh holds No.1 position in the most polluted countries ranking with an annual average concentration of 77.10 µg/m3 which is above 6.5 times of United States Environmental Protection Agency standard, followed by Pakistan (59.00 µg/m3) and India (51.90 µg/m3) for the fine particulate matter (PM2.5) pollution in 2020. And the top three most polluted regions in Bangladesh were Manikganj (80.2 µg/m3), Dhaka (77.1 µg/m3), and Ajimpur (55.7 µg/m3) in 2020.
PM2.5 are microscopic inhalable particles with diameters of 2.5 micrometers and smaller. The average human hair is about 30 times larger than the largest PM2.5 particle. A wide range of health effects caused by PM2.5 pollution and a study showed that 7 to 33% COVID-19 related deaths are linked to long-term air pollution exposure. A report by IQAir concluded that air pollution is contributing to about 7 million deaths annually.
The high PM2.5 levels occur during the dry season in Bangladesh, usually from November to March. The Air Quality Index (AQI) which is a scorecard corresponds to different level of health concern, has shown ‘Zero’ percentage (%) of ‘Good’ air quality days during the 2020-2021 dry season in the country. More than 90% of the time in the season, the particulate pollution level was in ‘Unhealthy’ and ‘Very Unhealthy’ categories.
Also, the country experienced ‘Hazardous’ air quality for 8% of the time in the season. If the air quality reaches to the ‘unhealthy’ category, everyone should limit the outdoor activities. When air quality is in ‘very unhealthy’ or ‘hazardous range’, an emergency health alert is recommended because everyone with the exposure more likely to be affected.
Writer: Iqbal Hossan, Engineer & Researcher, Arkansas, USA
BDST: 1305 HRS, APR 18, 2021