Delhi’s air quality improved marginally on Monday as wind speed picked up, dispersing the pollutants and the thick cover of hazardous haze that had been shrouding the national Capital for nearly a week. By Wednesday, wind speed is likely to increase more, bringing much needed relief to the gasping city, monitoring agency System of Air Quality and Weather Forecasting And Research (SAFAR) said.
On Monday, SAFAR had put 24-hour-average of PM 2.5 and PM 10 in the ‘severe’ category at 622 and 808 micrograms per cubic metre respectively till 5 pm. However, the alarming levels of pollution failed to dissuade Chhath devotees from bursting firecrackers early in the morning.
The 24-hour-average Air Quality Index (AQI) recorded by the Central Pollution Control Board (CPCB) was 423 on Monday as against Sunday’s 497, which was the season’s worst.
Visibility also improved as the city witnessed sunshine after several days. “The air quality has improved due to a little increase in wind speed, although the wind direction continues to be north-northwest. By Wednesday, wind speed is likely to increase and the wind will blow towards east to further improve the air quality and take it to ‘very poor’ from the present ‘severe’,” Project Director, SAFAR, Gufran Beig said.
The wind direction is important from the point of view of stubble burning in Punjab and Haryana as wind blowing from these States brings pollution-laden smoke to Delhi.
The Delhi Pollution Control Committee’s (DPCC) real-time readings displayed a downward trend cutting across its monitoring stations. The city’s pollution hotspot Anand Vihar had a PM 10 reading of 1,640 micrograms per cubic metre at 4 am. It came down to 580 by 5 PM while PM 2.5 was at 145 micrograms per cubic metre. At Punjabi Bagh, PM 10 came down to 214 micrograms per cubic metre at 5 PM from a high of 1,270 recorded at 10 am.
Other stations like Mandir Marg and RK Puram displayed similar trends. PM 2.5 and PM 10 are ultrafine particulates, the dominant pollutants in Delhi, which has recently been described as a “gas chamber” by Chief Minister Arvind Kejriwal.
The 24-hour prescribed standards of PM 2.5 and PM 10 are 60 and 100 respectively and prolonged exposure to anything beyond that harms the respiratory system and may cause cardiac complications.
Skymet Director Mahesh Palawat said strong winds from Punjab and Haryana will push the pollution away. “Due to adverse weather condition like slow wind speed, high humidity and low temperature, pollutants are hanging close to the surface. However, strong winds of about 15-20 kmph are expected from the northwest in the next 24-48 hours, which will help in fast dispersal of pollutants from the air,” Palawat said.
“On Tuesday morning, people may find mist due to low temperature. However, pollution level will go down and visibility will increase later in the day,” he added.