Sri Lanka is the twenty-fifth most polluted country in the world according to the IQAir AirVisual's 2019 World Air Quality Report. However, the country has been tagged as having the best air quality in South Asia according to the report in the region with pollution regarded as “moderate.” The rest of the region is listed as “unhealthy.”

According to IQAir AirVisual’s report, South Asia is home to 30 of the world’s 40 most polluted cities, and four of the five most polluted countries, owing to a toxic combination of belching vehicles, biomass burning for household cooking, agricultural burning, and coal combustion.

Bangladesh is the world’s most polluted country by weighted population average, followed by Pakistan and Afghanistan.

Indian and Pakistani cities again dominate the world’s most polluted cities for PM2.5 in 2019. Twenty-one out of the top 30 most polluted cities are located in India. Five of the top 30 most polluted cities are located in Pakistan.

The report noted that the country of 1.3 billion people still has a limited air quality monitoring network given its population size, with even populous cities lacking access to real-time air quality data.

The 2019 World Air Quality Report is based on data from the world’s largest centralized platform for real-time airquality data, combining efforts from thousands of initiatives run by citizens, communities, companies, non-profit organizations and governments.

The 2019 World Air Quality Report is based on a subset of the information provided through the platform. It includes only PM2.5 (fine particulate matter) data as acquired from ground-based air quality monitoring stations with high data availability.