Delhi's Air Quality 'Severe' for 2nd Day; Officials Say Stringent Action if Condition Persists

New Delhi: Delhi's air quality remained "severe" for the second consecutive day on Tuesday as high moisture content and low wind speed prevented pollutants from dispersing.

As a thick haze engulfed Delhi, authorities said they were weighing options like rationing of vehicles and a ban on construction activities in the National Capital Region to check the pollution level from sliding further.

The Central Pollution Control Board said Gurgaon's enforcement authorities have given the poorest performance in NCR in addressing complaints related to violation of norms through November; its implementation score was only 4.7 per cent.

Noida performed the best among NCR towns with an implementation score of 36 per cent, CPCB said. Delhi had an implementation score of 31.77 per cent, while Faridabad and Ghaziabad had 28 and 26.72 per cent respectively.

Implementation score is the ratio of action taken to incident reported.

The chairperson of the Supreme Court-appointed Environment Pollution Control Authority, Bhure Lal, said stringent actions would be taken if "severe" conditions persisted for another 48 hours. The actions include emergency measures like rationing of vehicles on roads and a ban on construction activities.

Lal said if winds pick up speed, Delhi's air quality might improve.

He hoped that rainfall predicted in the city on Wednesday will help improve the air quality.

The Central Pollution Control Board recorded an overall air quality index of 415 in Delhi on Tuesday. The AQI on Monday was 412.

Ghaziabad, Noida and Faridabad also recorded "severe" air quality. Ghaziabad's air quality was the worst with an AQI of 429, CPCB data showed. Gurgaon recorded "very poor" air quality.

An AQI between 201 and 300 is considered "poor", 301 and 400 "very poor" and 401 and 500 "severe".

Twenty one areas in Delhi recorded "severe" air quality and 10 areas recorded "very poor" air quality. Rohini, Sonia Vihar, Burari and Wazirpur edged towards "severe-plus emergency" category, the CPCB said.

Experts said even healthy people find it hard to breathe when the pollution level is "severe" and doctors advise residents to keep physical activity to a minimum.

The overall PM2.5 level fine particulate matter in the air with a diameter of less than 2.5 micrometre was recorded at 261 and the PM10 level at 449, it said.

The Centre-run System of Air Quality and Weather Forecasting said the air quality could improve to "very poor" by Wednesday. Meteorological conditions leading to insufficient rainfall often deteriorate air quality. Delhi is currently witnessing the said phenomenon, it said.

"There is a fall in temperature and good amount of moisture is present in the air. Moist air is passing over Delhi's cool surface leading to fog formation and calm winds are not allowing pollutants to disperse," SAFAR said.

"Levels of gaseous pollutants, NOx and CO, are forecast to be enhanced, up to moderate range, after a long time due to a fall in boundary layer height and reduced vertical mixing," it said.

According to the Indian Institute of Tropical Meteorology, the maximum ventilation index is likely to be 2,500 sqm/second from December 10-12.

The ventilation index lower than 6,000 sqm/second with an average wind speed of less than 10kmph is unfavourable for dispersion of pollutants.

CPCB said the most prominent polluting activities were construction, road dust re-suspension, open burning and traffic congestion in November. It has repeatedly termed the enforcement bodies' actions on public complaints against pollution "grossly inadequate".

On December 2, CPCB had sent show-cause notices to municipal bodies SDMC and EDMC for failing to check air-polluting activities, asking why their commissioners should not be prosecuted for inaction.

The Supreme Court had asked CPCB to prosecute government officials for not acting on around 250 complaints received by it from citizens.

"Why don't you prosecute these officials? You should prosecute them. Let these people realise what they have done," the top court had told CPCB.

EPCA chairperson Lal had also lashed out at the enforcement agencies for "not properly implementing" the directions issued to curb air pollution.

Delhi has been battling alarming levels of air pollution for over two months.