Gurugram least polluted city in NCR

After two days of almost clear skies, a toxic haze covered the city as the temperature dropped almost five degrees Celsius on Monday. Of all cities in the NCR, Gurugram air was the lest toxic, thanks to better wind speed.

On Monday, Gurugram’s Air Quality Index (AQI) value stood at 325, over a 100 points above the Sunday reading of 206, putting the city in the ‘very poor’ category once again. The daily average level of PM2.5, the primary pollutant, also shot up from 203ug/m3 on Sunday to 330ug/m3 on Monday, more than five times the safe limit of 60ug/m3.

Explaining this sudden shift, experts said this was due to a sudden drop in atmospheric temperature from 31° C on Sunday to 26.4° C on Monday. “Lower temperature means that the suspended particulate matter settles closer to the ground,” said Sachin Panwar, a city-based air quality expert.

Gurugram, however, was the least-polluted city in the NCR on account of high wind speed, which touched at least 14kmph, according to an IMD official who did not wish to be quoted. “Over the past two days, high wind speeds have cleaned up the city’s air. If it wasn’t for high wind speeds on Monday, the pollution in Gurugram would have been far worse,” said a member of the CPCB air quality lab in Delhi.

In comparison, Delhi, Noida, Ghaziabad and Faridabad’s air quality shot up from being in the ‘poor’ category on Sunday to ‘severe’. Delhi air was 426 on the AQI, while Noida, Faridabad and Ghaziabad AQI value stood at 433, 421 and 435, respectively.

On Monday, each of these cities recorded lower wind speed, in the region of about 8kmph.