Mumbaiites, breathe easy! Your city has cleanest air in past two years
Experts said rainfall, sea breeze were responsible for low pollution levels on Thursdaymumbai Updated: Oct 13, 2017 00:54 IST
Two days after the city’s pollution levels fell to its lowest since 2015, with the air quality index (AQI) - the pollutant measuring indicator - at 35; the air quality improved further on Thursday, with a reading of 32.
The city’s air quality, which falls under the ‘good’ category , is the best since air quality monitoring began in Mumbai in June 2015. On Tuesday and Wednesday, AQI levels had increased in the city to 51 and 53, both falling under the ‘good’ category.
The System of Air Quality Weather Forecasting and Research (SAFAR) that records air quality at four cities in India, found that Delhi had poor quality air, with an AQI reading of 273, Ahmedabad recorded 75 (good) and Pune 37 (good). Mumbai’s air quality was better than London (53), Sydney (55) and Beijing (154) on Thursday.
Researchers said weather factors was responsible for the low pollution levels. “The pollutants in the city have been cleaned up by rainfall during the earlier half of the week. Pollutant have also been swept away due to sea breeze; both these factors are part of the monsoon withdrawal process,” said Gufran Beig, project director, SAFAR. “We expect that pollution levels will shoot up within the next two to three days.”
Pollution levels were lowest in Mumbai for PM2.5 - particles smaller than 2.5 micron size that can easily enter the respiratory system and cause health ailments. A health advisory issued by SAFAR read, “Air quality is satisfactory, and air pollution poses little or no risk.” An AQI level between 0-100 is good, 101-200 is moderate, 201-300 is poor and 301 and above is very poor.
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 2016, the cleanest air was recorded on May 6 with an AQI of 64. In 2015, the cleanest air was recorded on July 13 with AQI levels at 84.
Meanwhile, 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).
As against a safe limit of 60 microgrammes per cubic metre (µg/m3) over 24 hours for PM2.5, Mumbai recorded levels at 19µg/m3 on Thursday and 21µg/m3 Monday. For PM10, Mumbai recorded 33µg/m3 on Thursday and 36µg/m3 on Monday for PM10 against a safe limit of 100µg/m3 for 24 hours.
All 10 locations in Mumbai recorded AQI levels in the ‘good’ category with Worli had the cleanest air with an AQI at 16, Navi Mumbai had the highest AQI at 42.
On Tuesday and Wednesday, AQI levels had increased in the city to 51 and 53, both falling under the ‘good’ category. The city can expect a similar air quality on Friday with a predicted AQI of 31.