Despite the geographical advantages and favourable meteorology, air pollution is rapidly becoming an issue in the western states of Maharashtra and Gujarat, according to recent research of regional air pollution levels by the Centre for Science and Environment (CSE).
“Between 2019 and 2021, the number of bad-air days in Mumbai has doubled, while the number of pleasant days has decreased by 20%. This emphasises the importance of stepping up action in all sectors to prevent future deterioration and halt the trend in this region” CSE’s executive director of research and advocacy, Anumita Roychowdhury, stated.
The study observed 56 continuous ambient air quality monitoring stations (CAAQMS) in 15 cities across two states: Maharashtra and Gujarat. Maharashtra had one station each in Aurangabad, Kalyan, Nagpur, Nashik, and Solapur, two in Chandrapur, four in Navi Mumbai, eight in Pune, and 21 stations in Mumbai. Gujarat had one station each in Ankleshwar, Nandesari, Vapi, and Vatva, four in Gandhinagar, and eight stations in
Even though there are many real-time monitors in a few cities in these states, many of them cannot be considered for long-term study due to data gaps and a lack of quality data, according to Avikal Somvanshi, programme manager for CSE’s Urban Data Analytics Lab.
The researchers discovered that in 2020, the year with the most lockdown periods, almost all cities in the region experienced a decrease in yearly average PM2.5 readings. However, there has been a recovery, and the trend is expected to continue in 2021.
The cities of Gujarat are more polluted than those of Maharashtra. The air in Vatva and Ankleshwar is the most polluted in the region, with an average PM2.5 concentration of 67 micrograms per cubic metre in 2021. Vapi and Ahmedabad are next, with yearly averages of 54 microgram per cubic metre and 53 microgram per cubic metre, respectively, for 2021.
Ankleshwar in Gujarat has the most unhealthiest days in the region, with 102 days of poor and very bad AQI, followed by Kalyan with 84 days, Vatva (75 days), and Navi Mumbai with 74 days (54 days).
Vapi has 48 days of poor and very poor AQI, however its data for 138 days is missing (mainly for the winter months). Despite meeting the annual norm, Mumbai has had 42 days of bad and very poor air quality
At 43 micrograms per cubic metre, Chandrapur, an industrial city in Maharashtra, has recorded levels that are slightly higher than the yearly guideline. Other stations have met the annual criteria, and after a decline in 2020, they are all on the rise in 2021.
Bad-air days start to build up in the western states’ cities at the end of December and last until the end of January.
Winter pollution affects cities in the Mumbai Metropolitan Region more than cities in other regions. According to the CSE, bad air days occur throughout the year in industrial areas, but they tend to congregate during the winter.