Bangladesh’s capital Dhaka ranked fourth worst in the Air Quality Index (AQI) on Wednesday morning.
It had an AQI score of 269 at 10:53am and the air quality was classified as ‘very unhealthy’.
Australia’s Canberra, Germany’s Munich and India’s Delhi occupied the top three slots for cities with worst air with respective scores of 856, 541 and 494.
When the AQI score is between 201 and 300, every city dweller may begin to experience health effects. But when the value is 301 to 500 or more, the air quality is considered hazardous. The city dwellers may begin to experience health warnings of emergency conditions in this case.
Australia has been engulfed by wildfires, including on the outskirts of Sydney, Melbourne and the capital, Canberra. In New South Wales, the worst-affected state, 97 fires were burning on Monday, and many of them could not be contained.
Australia's annual wildfire season, which peaks during the Southern Hemisphere summer, started early after an unusually warm and dry winter, according to AP. Record-breaking heat and windy conditions triggered devastating wildfires in New South Wales and Queensland states in September.
About 5 million hectares (12.35 million acres) of land have burned nationwide over the past few months, with 12 people confirmed dead and more than 1,000 homes destroyed. Nearly 100 fires were burning across the state of New South Wales, which is home to Sydney.
New South Wales state Rural Fire Services Commissioner Shane Fitzsimmons said this wildfire season is the worst on record and painted a bleak long-term picture
The AQI, an index for reporting daily air quality, informs people how clean or polluted the air of a certain city is, and what associated health effects might be a concern for them.
In Bangladesh, the AQI is based on five criteria pollutants - Particulate Matter (PM10 and PM2.5), NO2, CO, SO2 and Ozone (O3). The Department of Environment has also set national ambient air quality standards for these pollutants. These standards aim to protect against adverse human health impacts.
Bangladesh’s overcrowded capital has been grappling with air pollution for a long time. The quality usually improves during monsoon.