Diwali air pollution: Mumbai won’t breathe easy on Friday, says SAFAR
SAFAR had forecast the air quality in Mumbai would be satisfactory, with a predicted air quality index (AQI) of 84 for Wednesday.mumbai Updated: Oct 18, 2017 21:58 IST
Contrary to their forecast, pollution levels in the city rose on the first day of Diwali on Wednesday, findings of the System of Air Quality Weather Forecasting and Research (SAFAR) showed.
SAFAR had forecast the air quality in Mumbai would be satisfactory, with a predicted air quality index (AQI) of 84 for Wednesday. Pollution levels were, however, much higher with the AQI at 142 in the day and 176 in the evening, both in the ‘moderate’ category. The city also woke up to a thin layer of smog.
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.
According to the revised forecast, Mumbai can expect ‘moderate’ air quality on Thursday, with an AQI of 192. On Friday, the city is expected to record an AQI of 239, falling in the ‘poor’ category. The air quality is expected to improve from Saturday onwards with an AQI predicted at 181 (moderate), Sunday 161 (moderate), and Monday 138 (moderate).
Researchers from SAFAR said their original forecast, however, still stands true, as the air quality was the best ever for a Diwali day since SAFAR started monitoring (June 2015) it in Mumbai.
“The forecast was based on the emissions in 2016. The wind pattern changed from sea breeze (cool with high speed) to that coming from land (warm and slow). We have tallied predictions from the weather department and there is no possibility of rain in the coming days,” said Gufran Beig, project director, SAFAR. “The dispersion of pollutants will be slower than predicted before, leading to a rise in pollution levels. However, it will be lower than other mega cities.”
Of the 10 locations where air quality is measured in the city, as per Wednesday’s forecast, Nerul is expected to record the highest pollution levels on Thursday, followed by Bandra Kurla Complex, Mazgaon, Borivli and Andheri. The cleanest air in the city is expected at Worli.
SAFAR’s forecast said the highest levels of particulate matter (PM) are expected between 12am and 3am on October 19-20 (Thursday night to Friday early morning). PM2.5 - small particles predominantly a part of dust of 2.5 microns in size that can penetrate deeper into the lungs and enter the bloodstream – is expected to be above 100 µg/m3 (microgrammes per cubic metre) against a safe limit of 60 µg/m3.
“The most striking factor is that PM2.5 [relatively more harmful than coarser particles] is expected to increase by 20 per cent during Diwali as compared to normal days,” the forecast said.
“With regular air quality monitoring and forecast across major cities, the government and citizens can now take appropriate measures to shield themselves from poor air quality and devise techniques to reduce emissions from vehicles, open burning and construction dust. If required, reduce or stop the use of firecrackers,” said Anumita Roy Choudhury, executive director, Centre for Science and Environment, Delhi.