New Delhi, Nov 5 (PTI): A thick shroud of menacing grey haze blanketed the national capital today as pollution level breached the safe limit by over 17 times at places, prompting Chief Minister Arvind Kerjriwal to describe Delhi as a "gas chamber" and seek the Centre's intervention. Kejriwal appealed to people to minimise the use of private vehicles in view of the situation and switch to public transportation facilities.

The extent of pollution surpassed even the post-Diwali levels, while smog brought down visibility to around 200 metres across the city. Monitoring agencies recorded 'severe' quality air and advised people to avoid going outdoors.

Kejriwal told a press conference that the smog was mainly a product of raging farm fires in neighbouring Punjab and Haryana. Later, he raised the issue with Union Environment Minister Anil Dave in a meeting at the latter's residence.

While the 24-hour average of respirable pollutants PM 2.5 and PM 10 was 355 and 482 micrograms per cubic metre respectively, real-time figures were alarmingly high. Anand Vihar, for instance, recorded PM 10 level at 1,711 micrograms per cubic metre at 2 PM -- around 17 times above the safe limit.

The safe limits of these ultrafine particles are 60 and 100 respectively. Even the level of gaseous pollutants like NO2 violated the prescribed standards for human inhalation as per real-time readings.

Lt Governor Najeeb Jung has also called for a high-level meeting on Monday to take stock of the immediate, short-term and long term measures, in which he invited Kejriwal, health minister Satyendar Jain, environment minister Imran Hussain, the Delhi Chief Secretary, and representatives of Police and the civic bodies.

Kejriwal said vehicle restriction measures like 'odd-even' scheme will not be able to bring down the smog as initial studies suggest that the "large-scale" influx of pollutant-laden smoke from Punjab and Haryana has aggravated the situation. He said the Delhi government has very few methods at its disposal and the Centre needs to intervene.

"Pollution has increased to an extent that outdoors in Delhi are resembling a gas chamber. Prima facie the biggest reason seems to be burning of stubble in agricultural fields in Haryana and Punjab in huge quantity," Kejriwal told a press conference.

Shutting down of schools for a long time was not a feasible solution, he said, when asked about the decision of the civic bodies to keep schools run by it closed for a day in view of pollution.

Air Quality Index (AQI) of all the eight monitoring stations of Centre's SAFAR blinked red, indicating severe levels of pollution. CPCB stations had severe AQI as well. The Delhi High Court had last year observed that living in Delhi was akin to living in a "gas chamber" as it directed the Centre and the city government to present comprehensive action plans to combat it.

Meanwhile, Kejriwal pitched for providing alternatives and incentives to farmers so that they discard the traditional practice. "The Centre can sit with the Chief Minister of these states and chalk out a solution. Few reports have put the volume of stubble being burned at around 16-20 million tonnes.

"Fireworks during Diwali marginally added to the pollution. But other things inside Delhi did not drastically change. So the smog is mainly due to smoke from farm fires," he observed.

Kejriwal identified the main sources of pollution inside Delhi as vehicles, dust and waste burning, which he said could not be responsible for the pall of smog across the city.

"I saw smoke across Punjab, Haryana during my visits. We need Centre's help. We are hiring an agency in a week or two to study the sources of pollution in Delhi afresh," he said.