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Sunday plans unclear? Blame Mumbai’s smog

The smog comes less than a week after Mumbai recorded its cleanest air

mumbai Updated: Dec 10, 2017 00:14 IST
Badri Chatterjee
Badri Chatterjee
Hindustan Times
smog,air quality,SAFAR
Heavy smog at the Mumbai airport on Saturday.(Pramod Thakur/HT)

Haze over the city for the second day in a row ensured that pollutant-measuring indicator — air quality index (AQI) — entered the ‘poor’ category on Saturday. With an AQI of 212 (poor) in the morning and 237 (poor) in the evening, the air on Saturday was the worst since Diwali.

The concentration of PM2.5 — small pollutants that can easily enter the lungs, casing health hazards — was almost twice the safe limit on Saturday. As against the safe limit of 60 microgrammes per cubic metre (µg/m3), Mumbai recorded 109µg/m3. For PM10 — slightly larger particles — Mumbai recorded 169 µg/m3 as against 100 µg/m3, which is the safe limit.

This comes less than a week after Mumbai recorded its cleanest air, with an AQI of 43. The indicator rose to 124 (moderate) on Friday, according to the System of Air Quality Weather Forecasting and Research. An AQI of 226 (poor) is predicted for Sunday.

On October 19 (Diwali), Mumbai recorded poor AQI levels at 204 and 316 (very poor) on October 20. AQI levels between 0-50 is good, 51-100 is satisfactory, 101-200 is moderate, 201-300 poor, and 301-400 is very poor.

Doctors reported a rise in lung-related ailments. “We recorded 50 cases more than usual between Friday and Saturday,” said Dr Sanjeev Mehta, pulmonologist, Lilavati Hospital, Bandra.

SAFAR researchers said the haze was a mix of fog, from earlier that day, and smog from pollution.“There is a lot of moisture in Mumbai’s air owing to the passage of cyclone Ockhi. There were high-speed winds over the city when Ockhi passed. These have calmed down, allowing pollutant particles to settle close to the surface, and intensifying fog,” said Gufran Beig, project director, SAFAR. He said pollutants are expected to disperse from Monday onwards, owing to an increase in wind speed.

Mumbai’s visibility level, which usually ranges between 10,000 and 20,000 metres, reduced owing to heavy smog. Air traffic control said early flights were delayed by 15 minutes as visibility dropped to 800 metres.

However, it rose to 1,300 metres by the afternoon. Sources from the airport said visibility dropped by 100 metres during the evening. However, flight operations were unaffected as 1,000-metre visibility aids flight operations during take-off.

According to the weather bureau, the visibility at Santacruz was between 1,000 to 2,000 metres while Colaba ranged between 2,000 and 4,000 metres.

Haze is common during the winter, said officials. “Haze, dust and other particles are trapped at the lower most layer of the atmosphere, owing to low temperatures,” said KS Hosalikar, deputy director general, western region, IMD.

First Published: Dec 10, 2017 00:14 IST