As a thick haze engulfed Delhi two days ahead of Diwali, the national capital's air quality on Monday plunged sharply to "severe" for the second time in a week due to a change in wind direction which brought with it dust and smoke from farm fires raging in neighbouring states.
Experts warned the air quality is likely to worsen further due to local factors during the festival. Doctors said the impact of air pollution on public health can be compared to smoking 15-20 cigarettes a day.
The overall air quality index on Monday was registered at 418, a drastic decline from a day before when the AQI was moderate at 171.
Also, the PM2.5 (particles in the air with a diameter of less than 2.5 micrometres) and PM10 concentrations spiked to 'severe-plus emergency' category at 361 and 500 respectively, according to CPCB data.
A member of a Delhi-based think-tank called for action to minimize the use of private vehicles, which contribute almost 40 per cent to air pollution in the National Capital Region.
However, officials attributed the sudden, sharp deterioration in air quality to a change in wind direction, now blowing from the northwestern region towards Delhi, bringing with it dust and smoke from stubble burning in neighbouring states such as Punjab and Haryana.
The Indian Institute of Tropical Meteorology said the increase in PM2.5 concentration is due to a change in wind direction and because of biomass burning in neighbouring areas.
The Centre has said it is making efforts to improve the air quality but added that factors like weather, wind speed and stubble burning in states are not under its control.
"No leniency will be shown towards those who violate the pollution norms," Vardhan said on the sidelines of an event.
He urged people to indulge in "green deeds" and behave in a manner that is friendly to the environment.
The government has launched a 10-day 'Clean Air Campaign' from November 1 to monitor and report polluting activities. It has ordered halting of construction activities and regulating vehicular traffic in Delhi.
Civil construction has been suspended in the National Capital Region. All stone crushers and hot mix plants generating dust pollution have also been closed.
Anumita Roychowdhury, an executive director at the Delhi-based Centre for Science and Environment, asked when the authorities are ramping up emergency actions on all sectors why should vehicles be spared.
"The proposed action on private vehicles has to be seen within the larger context of how we are gradually ramping up emergency actions on all sectors," she said during a Facebook Live online programme, aptly titled 'Season of Smog'.
She said traffic would increase due to festival shopping over the next two days which would further worsen the air quality.
"Today we have gone to the extent of shutting power plants, brick kilns, hot mix plants and even gensets, the cars are actually coming last.
"So to say, to make exception to cars is very wrong keeping in mind that all the new estimates are showing that private vehicles contribute towards 40 per cent of pollution."
The environment minister said the Centre has given an aid of over Rs 550 crore for farmers to discourage them from indulging in stubble burning.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)