Mercury picks up but air quality remains a concern

Gurugram Air quality in the city remained in the ‘severe’ category of the Central Pollution Control Board’s (CPCB) air quality index (AQI) bulletin for the second

Gurugram Air quality in the city remained in the ‘severe’ category of the Central Pollution Control Board’s (CPCB) air quality index (AQI) bulletin for the second consecutive day on Thursday, with an index value of 429. This was up slightly, from the previous day’s reading of 416, and substantially more than Tuesday’s reading of 342 (indicating ‘very poor’ air). Experts and officials attributed the uptick to a recent dip in atmospheric temperature, which causes suspended particulate matter to settle closer to the earth, and slow winds.

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Both the minimum temperature and maximum temperature rose on Thursday, from 2 degrees Celsius to 5 degrees Celsius, and from 17 degrees Celsius to 18 degrees Celsius, respectively. On Thursday evening, most private air quality monitors across the city showed air quality to be in the ‘poor’ category of the AQI, with index values ranging from 203 to 247.

As per a CPCB forecast, the predicted 24-hour AQI for Gurugram on Friday is 277 (also in the ‘poor’) category. The maximum temperature is expected to remain stable, while the minimum temperature is predicted to climb further, to touch 8 degrees Celsius on Friday.

Wednesday was Gurugram’s coldest night of the winter, with the minimum temperature dipping to 2 degrees Celsius, the lowest since the 2.4 degrees Celsius recorded on December 28 last year.

“Due to this, since early Wednesday, very foggy conditions have been prevailing in the city due to dust pollutants settling at a lesser mixing height,” a senior scientist with the CPCB’s air quality lab in Delhi said. Slow winds (of not more than six kilometres per hour) are not facilitating the effective dispersal of pollutants either, the official said.

The average daily concentration of finer particulate matter, having a diameter less than 2.5 micrometres (PM2.5), the city’s most prominent pollutant, on Thursday was 429ug/m3, as per the HSPCB’s official air quality monitor at Vikas Sadan. However, while the concentration of pollutants was particularly high on Wednesday and during the early hours of Thursday, increased sunlight during Thursday afternoon helped create warmer conditions that alleviated the severity of pollution.