Gurugram records ‘very poor’ air quality for second consecutive day

Friday’s IITM forecast said that the air quality over Delhi NCR is likely to remain “very poor” from Saturday to Monday. It added that the air quality during the subsequent six days is likely to remain the same or improve slightly from the “very poor” to the “poor” category

The lowering of the mixing height of airborne pollutants and a low wind speed on Friday ensured that Gurugram’s air quality remained in the “very poor” category for the second consecutive day with an Air Quality Index (AQI) reading of 333, experts and officials of Indian Institute of Tropical Meteorology (IITM) said.

Sachin Panwar, city-based air quality expert, reiterated that the mixing height, or boundary layer, of airborne pollutants reduces to 100 metres in the morning, leading to a rise in pollution. (ANI)

According to officials of the pollution department, three of the four monitoring stations in the city recorded “very poor” air, with the Sector 51 monitoring station reporting the highest AQI reading of 376 (very poor). An AQI reading between zero and 50 is considered “good”, 51 and 100 “satisfactory”, 101 and 200 “moderate”, 201 and 300 “poor”, 301 and 400 “very poor”, and 401 and 500 “severe”.

Gurugram recorded an AQI reading of 362 (very poor) on Thursday, a rapid deterioration from the AQI reading of 242 (poor) the day before. Experts also attributed the decline in air quality over Delhi-NCR to a change in wind direction, which is bringing cooler air from the hills towards the region causing pollutants to accumulate.

According to IITM, the mixing height of airborne pollutants has reduced from about 1km (considered moderate) to around 100 metres (which is shallow), and the wind is blowing at a low speed of 6kmph.

Friday’s IITM forecast said that the air quality over Delhi NCR is likely to remain “very poor” from Saturday to Monday. It added that the air quality during the subsequent six days is likely to remain the same or improve slightly from the “very poor” to the “poor” category.

“The predominant surface wind is likely to blow from the south/northeast direction in Delhi with a speed of six to eight kmph. There will mainly be a clear sky from October 29 to 31,” the forecast said.

Sachin Panwar, city-based air quality expert, reiterated that the mixing height, or boundary layer, of airborne pollutants reduces to 100 metres in the morning, leading to a rise in pollution. “The count of farm fires in Punjab, Haryana and Uttar Pradesh has risen significantly in the past few days and the wind has changed direction, bringing pollutants from these areas to Delhi-NCR. The low wind speed is adding to the problem and there is little dispersal of pollutants,” he said.

According to IITM data, the number of farm fires on October 28 was 2,067 in Punjab and 123 in Haryana, a significant spike from October 27’s count of 1,111 in Punjab and 83 in Haryana.

Panwar warned that the pollution is likely to rise further in the coming days with a dip in temperature expected from the first week of November. He said the air quality might worsen into the “severe” category from the second week of November, but before that there could be a window of relief for a couple of days due to a forecast of rain.

CPCB, meanwhile, said that PM10 was the primary pollutant in the city’s air on Friday, and added strong winds blowing from the northwest are likely to transport more smoke from farm fires towards Delhi.