The air quality in Delhi improved on Tuesday as the day progressed, though it remained in the “very poor” category. At 10 am, the Air Quality Index in the city was recorded at 400, just one point below turning “severe”, but improved to 320 by 6 pm, according to the Central Pollution Control Board.
On Monday, the index had turned “severe” in Delhi, Faridabad, Ghaziabad, Greater Noida, and “very poor” in nearby Gurugram and Hapur.
The Centre-run System of Air Quality Forecasting and Research, or SAFAR, recorded the levels of PM10 and PM2.5 under “very poor” category. Levels of PM2.5 shot up nearly five times in 24 hours on Monday. Officials said such a spike in levels had not been recorded since hourly monitoring began for the region three years ago, Hindustan Times reported.
Scientists from government agencies said they had expected pollution levels to increase, but did not expect it to happen so rapidly. “The prediction was that air quality could deteriorate to ‘very poor’ levels,” an unidentified official of the Central Pollution Control Board said. “We have not encountered such an overnight spike in the last three years at least.”
Officials said the sudden deterioration was due to a change in the direction of wind, now blowing from the north-western region towards Delhi, bringing with it dust and smoke from stubble burning in neighbouring states, reported The Economic Times.
An unidentified official of SAFAR said stubble burning accounted for 24% of the air pollution in the national capital. The Indian Institute of Tropical Meteorology said the increase in PM2.5 concentration was due to a change in the wind direction and biomass burning.
Bharatiya Kisan Union General Secretary in Punjab Harinder Singh Lakhowal told Hindustan Times that many farmers cannot afford to use machinery that can clear crop residue. “Those who can afford the additional diesel costs during the use of machinery are not burning stubble,” Lakhowal said. “Rest of the farmers are helpless.”
A group of people protested outside the office of the Environment Ministry on Tuesday, demanding clean air and speedier implementation of the National Clean Air Programme, PTI reported. They asked the government to ensure stubble burning is stopped in areas around Delhi, and also delivered a letter listing out their demands to the ministry’s Deputy Secretary Satyendra Kumar.
‘Pollution expected to worsen’
On Monday, SAFAR said that Delhi’s air quality is likely to deteriorate to the “severe-plus emergency” category after Diwali. Air quality will be “bad” on November 8 even if “partial toxic crackers” are used compared to last year.
Central Pollution Control Board Member Secretary Prashant Gargava said it has advised transport authorities to prohibit heavy vehicles from entering the city from November 8 to November 10, PTI reported. An unidentified official of the pollution board said the recommendation was made as such vehicles cause heavy pollution, which could lead to a further decline in air quality.
Another senior official said the Central Pollution Control Board could consider inducing artificial rain after Diwali to wash away hazardous pollutants. The pollution board is in talks with the Indian Institute of Technology, Kanpur, and the India Meteorological Department, and will wait for meteorological conditions to stabilise before using cloud-seeding.
Cloud seeding is the process of combining chemical agents such as silver iodide, dry ice and common salt with existing clouds to increase the chance of rain or snowfall.
“We are supporting the project by providing salt mix for inducing artificial rain,” an unidentified IIT Kanpur professor who is a part of the project told PTI. “The weatherman is monitoring weather conditions to become favourable for creating artificial rain.”