The air in Dhaka was categorised as ‘very unhealthy’ as the capital city had an AQI score of 247 at 12:23 pm.
When the AQI score is between 201 and 300, every city dweller is likely to be affected.
Also read:Dhaka's air quality improves significantly
Delhi of India and Lahore of Pakistan occupied the first and second place in the list of cities with the worst air quality with AQI scores of 282 and 273 respectively.
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).
Also read:Air Quality Index: Dhaka ranks 5th worst
Bangladesh has a subtropical monsoon climate characterized by wide seasonal variations in rainfall, high temperatures and humidity.
Generally, Dhaka’s air starts getting fresh when rain starts from mid-June. The air remains mostly acceptable during monsoon from June to October.
World’s most polluted country
Bangladesh topped the list of the world’s most polluted countries in 2019 for PM2.5 exposure, according to an IQAir AirVisual report.
Also read:Air Quality Index: Dhaka ranks 7th worst
The 2019 World Air Quality Report is based on data from the world’s largest centralised platform for real-time air quality data, combining efforts from thousands of initiatives run by citizens, communities, companies, non-profit organisations and governments.
It includes only PM2.5 (fine particulate matter) data as acquired from ground-based air quality monitoring stations with high data availability.
To track outdoor air quality, the report focused on the concentrations of two pollutants in particular: fine particle air pollution (particulate matter measuring less than 2.5 micrometers in aerodynamic diameter, or PM2.5) and ozone found near ground level (tropospheric ozone).
This assessment also tracked exposure to household air pollution from burning fuels such as coal, wood, or biomass for cooking.
Also read Dhaka's polluted air makes Covid fight harder
Air pollution consistently ranks among the top risk factors for death and disability worldwide. Breathing polluted air has long been recognized as increasing a person’s chances of developing heart disease, chronic respiratory diseases, lung infections, and cancer, according to the report.
As per the World Health Organization (WHO), the air pollution kills an estimated seven million people worldwide every year largely as a result of increased mortality from stroke, heart disease, chronic obstructive pulmonary disease, lung cancer and acute respiratory infections.
Over 80 percent living in urban areas which monitor air pollution are exposed to air quality levels that exceed WHO guideline limits, with low- and middle-income countries most at risk, WHO estimated.