Diwali pollution in Mumbai: Expect ‘very poor’ air quality today
SAFAR estimated pollution levels to further increase on Friday with the air quality reaching the ‘very poor’ markmumbai Updated: Oct 19, 2017 23:29 IST
The city recorded a spike in pollution levels on Thursday as the pollutant-measuring indicator – air quality index (AQI) was 204, which entered the ‘poor’ category as a result of emissions from firecrackers and changing weather patterns, said researchers from System of Air Quality Weather Forecasting and Research (SAFAR).
SAFAR estimated pollution levels to further increase on Friday with the air quality reaching the ‘very poor’ mark with a predicted AQI of 303. The city’s air quality is expected to remain in the ‘poor’ category till Sunday and improve from Monday onwards. On Thursday, while Delhi recorded ‘very poor’ air quality, Pune and Ahemdabad recorded cleaner air (moderate) than Mumbai.
AQI level from 0-50 is considered good, 51-100 is satisfactory, 101-200 is moderate, 201-300 is poor, 301-400 is very poor, and 401 and above is severe.
However, pollution levels were much lesser this Diwali as compared to the last two years. Mumbai recorded high pollution levels last Diwali (October 30, 2016), with an AQI of 278 (poor) on Diwali day and 315 (very poor) the day after. In 2015, the city recorded an AQI of 279 (poor) on Diwali day (November 11) and 313 (very poor) the day after.
Researchers said air quality would breach the ‘very poor’ mark on Friday because dispersion of pollutants accumulated in the city’s air will not be fast. “External emissions such as firecrackers and open burning are the main reasons for the rise in pollution. Since the wind pattern changed from sea breeze to land breeze, there was drop in wind speed. This combined with no rainfall has resulted in pollutants getting stagnated in the city’s air close to the surface forming a layer of smog,” said Gufran Beig, project director, SAFAR.
Of the 10 locations where SAFAR monitors air quality, Nerul (representative of Navi Mumbai) had the most polluted air with an AQI of 311 (very poor), followed by Mazgaon at 303 (very poor). While majority of locations were either in the ‘poor’ or ‘moderate’ categories (see box), the cleanest air was recorded at Chembur at 98 (satisfactory).
SAFAR issued an advisory for Friday regarding ‘very poor’ air quality. “People with heart or lung disease, older adults, and children should avoid prolonged or heavy exertion; everyone else should reduce prolonged or heavy exertion,” it read.
On Thursday, as against a safe limit of 60 microgrammes per cubic metre (µg/m3) for particulate matter PM2.5 - small particles predominantly a part of dust of 2.5 micron size, and are considered unsafe as they can penetrate deeper into the lungs and enter the bloodstream -, Mumbai recorded 92µg/m3, which is expected to rise to 124µg/m3 on Friday. For PM10 – coarser particles of 10 micron size, the city recorded 154µg/m3 on Thursday against a safe limit of 100µg/m3, which is expected to rise to almost double on Friday at 198µg/m3.
The health effects statement issued by SAFAR for Friday read, “Triggers health alert. Everyone may experience more or serious health effects with significant increase in respiratory effects in general population.”