Mumbai breathes cleanest-ever air on Monday since 2015
AQI levels fell in the ‘good’ category and the health advisory read, “Air quality is satisfactory, and air pollution poses little or no risk.”mumbai Updated: Oct 10, 2017 09:34 IST
Uniform rainfall across the city in the past two days led to the city recording its cleanest air day on Monday since June 2015, when air quality monitoring and forecasting began in Mumbai.
The air quality index (AQI) — pollutant measuring indicator — was 35 for PM2.5 — particles smaller than 2.5 micron size that can easily enter the respiratory system and cause health ailments — according to the System of Air Quality Weather Forecasting and Research (SAFAR). AQI levels fell in the ‘good’ category and the health advisory read, “Air quality is satisfactory, and air pollution poses little or no risk.”
Researchers from SAFAR said it was a unique phenomenon because there was uniform rainfall across the Mumbai Metropolitan Region and surrounding areas, which had not been witnessed through the monsoon season so far. “There has been uniform rainfall within Mumbai and its surrounding areas like Thane, Navi Mumbai and even as far as Lonavla. As a result, all pollutants have been dispersed uniformly and completely washed out, resulting in the cleanest air recorded by us over the past two years. In the past, even if there was good air quality in Mumbai, pollution in the surrounding industrial areas affected the overall air quality of the city,” said Gufran Beig, project director, SAFAR. “We can expect similar AQI levels for till Wednesday and thereafter a rise in pollution levels is expected.”
Pollution levels in Mumbai were much better than London, which recorded PM2.5 AQI levels at 77, Singapore recorded 30 and New York recorded 5. Meanwhile, Delhi’s AQI was at the borderline between ‘poor’ and ‘very poor’ levels at 300.
The city could expect similar air quality on Tuesday as SAFAR predicted an AQI of 39 for PM2.5. On Monday, the AQI level for PM10 was 37 (good); ozone (O3) was 36 (good). An AQI level between 0-100 is good, 101-200 is moderate, 201-300 is poor and 301 and above is very poor.
In 2016, the cleanest air was recorded on May 6 with an AQI of 64. Earlier this year, Mumbai recorded an AQI of 75 on March 10, 59 on April 19 and on June 9 it was 48, all falling under the ‘good’ category. In 2015, the cleanest air was recorded on July 13 with AQI levels at 84. Mumbai recorded high pollution levels last Diwali (October 30, 2016) with an AQI of 278 (poor) on Diwali day and 315 (very poor) a day after Diwali (October 31).
Meanwhile, the Central Pollution Control Board under the Union environment ministry recorded AQI of 69 at both Bandra and Airoli air monitoring stations, falling under the ‘satisfactory’ quality with PM 2.5 as the dominant pollutant.
As against a safe limit of 60 microgrammes per cubic metre (µg/m3) over 24 hours for PM2.5, Mumbai recorded levels at 21µg/m3 on Monday. For PM10, Mumbai recorded 36µg/m3 for PM10 against a safe limit of 100µg/m3 for 24 hours.
Even though a major fire broke out in an oil tank on the Butcher Island on the east coast of Mumbai on Saturday, the air quality in Mumbai was not affected. However, HT had report on Monday that tourists visiting Elephanta caves complained of soot particles on their clothes, which researchers termed deadly because they contain black carbon. “Owing to the wind pattern, which is westerly moving from the sea to land, and as per the location of Butcher Island, the soot particles moved towards the opposite side of Mumbai and did not affect the city’s air quality,” said Beig.
All 10 locations in Mumbai recorded ‘good’ air quality on Monday with Bandra Kurla Complex (BKC) having the highest AQI at 59 and Worli having the cleanest air at 15. Navi Mumbai, where the FIFA under 17 World Cup is taking place recorded an AQI of 53.