IQAir’s 2021 report: Mumbai’s pollution level 9 times above WHO limit

Last year, the PM 2.5 annual average had worsened in Mumbai. It was 41.3 µg/m3 in 2020 and 45.3 µg/m3 in 2019, said the IQAir’s 2021 World Air Quality Report.

The findings are based on the country’s PM 2.5 annual average — airborne particles with less than 2.5 microns in diameter. PM 2.5 is one of the major pollutants contributing to air pollution in the city.

The data reveals that January 2021 saw the highest monthly average concentration of PM 2.5 at 98.5 µg/m3. In comparison, the highest monthly average concentration of PM 2.5 was recorded in December 2020 at 70.6 µg/m3.

As per records, Mumbai witnesses high pollution levels in December and January and lowest air pollution levels are recorded post monsoon in September.

As traffic congestion was minimal during the 2020 Covid-19 lockdown, the lowest PM 2.5 monthly average was recorded in June at 15.9 µg/m3. In 2021, the lowest PM 2.5 monthly average was recorded in September at 15.3 µg/m3. PM 2.5 levels below 25 µg/m3 were recorded for four months of monsoon in 2021, the report stated. It added that no city in India has met the WHO air quality guideline of 5 µg/m3.

In 2021, 48 per cent of India’s cities exceeded 50 µg/m3, or more than 10 times the WHO guideline. India was home to 14 of the world’s 20 most polluted cities, according to the report, which gathered data for 117 countries.

India’s PM 2.5 annual average reached 58.1 µg/m3 in 2021, ending a three-year trend of improving air quality. The country’s PM 2.5 annual averages have now returned to pre-quarantine levels of 2019.