Mumbai: ‘Pollution levels spiked in Oct; highest so far in 2020’
The average AQI was 149 (moderate) in October in Mumbai as against 83 in the same month last year
MUMBAI: Mumbai recorded the worst air quality across Maharashtra in October, which was also the month with the worst recorded air quality in the year so far, according to the Maharashtra Pollution Control Board (MPCB).
On its website, MPCB released a month-wise datasheet of air quality index (AQI) for 20 locations in Maharashtra on Monday. So far in 2020, the average air quality index (AQI) was 149 (moderate) in October in Mumbai. Across Maharashtra, Thane and Dombivli had the worst air quality in 2020 during the first 13 days of November. The AQI for both was at 204 (poor). Both areas recorded AQI of 111 (moderate) in October. The cleanest air across Maharashtra was recorded at Nasik in July, at 21 (good).
Last year, Mumbai’s air quality during October and November was better, with AQI readings of 83 and 116 due to successive cyclones in the Arabian Sea, said MPCB. “Especially during cyclone Kyarr, fastmoving winds did not allow pollutant suspension near the surface in 2019,” said SC Kollur, chief scientist, MPCB.
This year, the AQI was 147 (moderate) in February; 137 (moderate) in January, and 108 (moderate) in March.
The air quality was much better between April and September (see box) when it ranged in the satisfactory category. The best air quality was recorded in July when the AQI was 45 (good). “This year, combined with the lockdown due to Covid-19 followed by the monsoon, overall air pollution has been much lower than previous years,” said Kollur. “The lockdown allowed us to record baseline air quality for major Maharashtra cities and identify sources of human-induced air pollution to be addressed through city-specific action plans,” he said.
Earlier this month, Mumbai received the lion’s share of
funds (₹244 crore) from the Central government, specifically to address air pollution based on the 15th Finance Commission’s recommendation.
However, January 2019 recorded high levels of air pollution with an AQI of 193 (moderate)
followed by February and March at 164 and 140 (both moderate) respectively. The best AQI was in August (54).
“AQI is related to the compilation of real-time data for 24 hours which has been averaged out for a month. It is a dynamic parameter to measure pollutants depending on activities on the ground level and the second is the weather conditions,” said Kollur, adding that Mumbai being a coastal city, its
AQI was greatly affected by weather parameters irrespective of human-induced emissions.
“The example was visible during the Diwali period when a day before Diwali [November 13] the air quality was bad but owing to a rise in wind speed and increase in temperature, there was a dynamic change in air quality on Diwali and postDiwali air pollution despite the use of firecrackers,” he said.
According to MPCB, the monthly average AQI is a mean of pollutants such as particulate matter (PM2.5 and PM10), ozone (O3), nitrogen dioxide (NO2), sulfur dioxide (SO2) and carbon monoxide (CO) emissions as a single value.
The higher the AQI value, the greater the level of air pollution and the greater the health concern.
LAST YEAR, MUMBAI’S AIR QUALITY DURING OCTOBER AND NOVEMBER WAS BETTER, WITH AQI READINGS OF 83 AND 116 DUE TO SUCCESSIVE CYCLONES IN THE ARABIAN SEA, SAID MPCB