Dhaka was the world's second most polluted capital city in 2018, two groups monitoring air pollution said on Tuesday in a study of the amount of fine particulate matter known as PM2.5 in 61 capital cities around the world.
The Bangladesh capital, home to over 17 million people, fell behind New Delhi and was followed by Kabul, according to the study by IQ AirVisual, a Swiss-based group that gathers air-quality data globally, and Greenpeace. New Delhi's average annual concentration of PM2.5 in a cubic metre of air was 113.5 in 2018 while it was 97.1 for Dhaka, the groups said in their report, reports Reuters.
PM2.5, or particles of 2.5 micrometers or less in diameter, is so dangerous because it lodges deep in the lungs.
The World Health Organization sets a daily mean air quality guideline of 25 micrograms of PM2.5 per cubic metre of air.