The air of Bangladesh’s capital, Dhaka city, showed a slight improvement on Saturday morning.
It ranked 12th in the Air Quality Index (AQI) with a score of 112 at 8:35am, indicating that the air is “unhealthy for sensitive groups,” reports UNB.
When the AQI value is between 101 and 150, members of sensitive groups may experience health effects while general public is less likely to be affected.
China’s Shenzhen and Thailand’s Chiang Mai occupied the first and second spots respectively with scores of 379 and 175.
Scores between 201 and 300 is classified as “very unhealthy.” If the score is between 301 and 500, then it is classified as “hazardous.”
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.
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.
Dhaka, one of the most densely populated cities in the world, has been grappling with air pollution for a long time and continuously ranks among the world's most polluted cities.
The air quality generally worsens during summer and shows signs of improvement in monsoon when the dust settles.
Brick kilns, vehicles run on fuel containing higher levels of sulphur, as well as construction work, have all been identified as major sources of air pollution.
Air quality further declines during the dry months -- from October to April -- but improves during the monsoon.
Dhaka city has been on a shutdown, alongside rest of the country, since March 26 with thousands of vehicle off the road. But, the city’s air pollution situation has not changed much.
When it comes to Bangladesh standard, the quality has indeed improved significantly, but is still behind in the global standard, as the pollution in the city continues to remain worst in the world ranking table.
