Gurugram AQI ‘very poor’ for third consecutive day

The city’s air quality continued to be in the “very poor” category for the third consecutive day on Monday, with a 24-hour average air quality index (AQI) reading of 305, according to the 4pm daily bulletin of the Central Pollution Control Board (CPCB). The AQI was more or less the same as that of Sunday’s 308 but a marked improvement from Saturday’s 357, though all three figures fall in the “ very poor” category.

However, individual readings from the three AQI monitors in Gwal Pahari, Sector 51 and Teri Gram were 342, 324 and 320, respectively, at 11am Monday, which were higher than the average AQI.

An AQI between zero and 50 is classified as “good”, 51 and 100 is “satisfactory”, 101 and 200 “moderate”, 201 and 300 “poor”, 301 and 400 “very poor”, and 401 and 500 is “severe”, as per the CPCB.

By 7pm Monday, the Gwal Pahari monitor registered a significant improvement with a reading of 293, while Sector 51 stood at 300, both in the ”poor” category. The monitor in Teri Gaon recorded AQI at 302 at 7pm, which again fell in the ”very poor” category.

Nishant Kumar Yadav, deputy commissioner of Gurugram, said they were keeping a close watch on the situation along with the Haryana State Pollution Control Board and the India Meteorological Department and the Commission for Air Quality Management (CAQM).

“Authorities are ensuring that no violation of earlier restrictions such as the construction ban takes place,” he said.

“We will enforce restrictions whenever required or asked by the CAQM. We urge citizens to ensure that vulnerable sections of people or those having breathing ailments stay indoors and venture out only when absolutely essential,” Yadav said.

Sachin Panwar, an environmentalist, said east and south-easterly winds are helping disperse pollutants that remained suspended in the air over the past week.

“The wind speed has marginally increased to 6-7km per hour. Along with that, wind gushes were also being recorded, of speeds of up to 10-12km per hour,” he said, adding that the mixing height of pollutants has also increased to 800-900 metres, from the 100 metres or below mark until last week.

Panwar said all these factors have helped in improving the AQI and it will continue to improve further in the next two to three days.

Panwar said going by meteorological factors, the AQI would again climb to “severe” category after November 12. He said north-east winds will start blowing by then and daytime temperatures would start to drop to about 20 degrees Celsius. The minimum temperature, meanwhile, would reach 16-17 degrees Celsius and would result in an increase in pollutants in the air.

“Right now, for the next two or three days, the afternoons would remain bright, clean and sunny; the AQI would deteriorate only between evening and morning hours. After November 12, the situation would change and the air quality may again drop to “severe” levels due to a change in wind direction,” he said.

Panwar said the AQI may remain at the lower end of ”poor” category for two to three days from November 20 as showers are expected in the hills, which would result in cold northern or north-western winds blowing through the plains.

“However, soon after, the situation would again aggravate and AQI would remain in the higher side of ”very poor” or in the ”severe” category due to thermal inversion,” he added.

Panwar said there will be a phase of three to four days in mid-December when the AQI will improve to ”satisfactory” or lower side of ”poor” levels, owing to light rain expected on account of a depression in the Bay of Bengal.

“It would also bring with in easterly winds which would give an improved phase of air quality. But afterwards, the situation would again deteriorate,” he added.

It may be recalled that the AQI had reached the “severe” category in Delhi-NCR, including Gurugram a week ago, forcing the Commission for Air Quality Management (CAQM) to invoke restrictions under stage 4 of the graded response action plan (Grap) on November 3. These stringent restrictions were lifted on Sunday after the AQI improved to “very poor” levels.

Gurugram district administration also revoked the Grap-4 restrictions on Sunday only a few hours after they were enforced in the city. However, the earlier ban on construction and demolition would remain in place, district officials said.

The AQI of Delhi was also in the ”very poor” category on Monday. Even though stage 4 restrictions were lifted in the national capital, BS-IV diesel vehicles and BS-III petrol vehicles are still banned in Delhi, along with construction and demolition activities, with certain exemption.