Is Mumbai’s air worse?

MUMBAI: An analysis of air quality data from 37 cities in the country has shown that Mumbai, Navi Mumbai, Nashik and Chandrapur in Maharashtra have reported an increase in particulate matter pollution between January 2019 and December 2021.

The analysis conducted by advocacy group Climate Trends was based on data from the Central Pollution Control Board (CPCB) network of Continuous Ambient Air Quality Monitoring Stations (CAAQMS) and was released on Monday to mark three years of the launch of the Centre’s National Clean Air Program (NCAP).

The programme aims to reduce particulate matter pollution in non-attainment cities — where air quality does not meet the permissible criteria as given in the National Ambient Air Quality Standards — by 20 to 30% by 2024 (compared to 2017 baselines).

“Despite the Covid-19 resultant lockdown, Mumbai’s annual PM 2.5 levels were higher in 2020 as compared to 2019,” the report titled Three years of the NCAP: A status check, said. The safe annual threshold for PM2.5, as per the World Health Organisation, is 5ug/m3. The safe annual threshold for PM10 is 15ug/m3. India’s national safe limits for PM 2.5 and PM10 are 40ug/m3 and 60ug/m3, respectively.

PM refers to small, respirable airborne particles less than 2.5 and 10 micrometres in diameter, which can enter the bloodstream through the lungs and trigger a range of respiratory and cardiovascular ailments.

In Mumbai, Climate Trend’s analysis shows, the annual average concentration of PM2.5 increased by 38%, from 37ug/ m3 (micrograms per cubic metre of air) in 2019 to 47ug/m3 in 2021. In terms of PM10 pollution, Mumbai saw a 27% increase in the annual average concentration, from 82ug/m3 in 2019 to 104ug/m3 in 2021.

Navi Mumbai, meanwhile, saw PM2.5 levels rise by 36% and PM10 levels rise by 27%. In Nashik, the uptick was less severe. PM2.5 levels rose by 5% while PM10 levels dipped by 6%. In Chandrapur, PM2.5 levels rose by 17%, while PM10 levels remained stable.

Dr VM Motghare, joint director (air pollution control) with the Maharashtra Pollution Control Board (MPCB), declined to comment on the apparent increase in pollution in these cities. However, an MPCB air quality analysis for 19 non-attainment cities between January 2017 and September 2021 showed that with the exception of Chandrapur, nearly all cities (including Mumbai, Navi Mumbai and Nashik) saw marginal improvements in pollution levels. Shared in November over a presentation, the analysis revealed that Mumbai’s annual average PM10 levels dropped from 125ug/m3 in 2017 to 113ug/ m3 in 2019 to 106ug/m3 in 2021. In Navi Mumbai, PM10 levels dropped too.