Delhi woke up to 'severe' air quality today under a blanket of thick haze, as pollution levels breached the permissible standards by multiple times.

The rapid fall in air quality and visibility began last evening itself as moisture combined with pollutants shrouded the city in a thick cover of haze.

By 10 am today, the Central Pollution Control Board (CPCB) recorded 'severe' air quality, meaning the intensity of pollution was extreme.

In light of the sudden dip, measures under the Graded Response Action Plan (GRAP) such as a four times hike in parking fees may be rolled out by the Supreme Court-mandated Environment Pollution Prevention and Control Authority.

If the situation deteriorates further and persists for at least 48 hours, the task force under the GRAP will mull shutting schools and enforcing the odd-even car rationing scheme.

The last time air had turned 'severe' was on October 20, a day after Diwali festivities, when firecrackers were set off.

Since then, the pollution monitors have been recording 'very poor' air quality, which is comparatively better than 'severe' but alarming according to global standards.

A 'very poor' AQI comes with the warning that people may develop respiratory illness on prolonged exposure while exposure to 'severe' air affects healthy people and seriously impacts those with existing respiratory or cardiovascular diseases.

IMA declares Delhi in public health emergency state,schools shld be shut & ppl must avoid stepping out-IMA Pres Dr.KK Aggarwal #AirPollution pic.twitter.com/mJ3SbVlGft — ANI (@ANI) November 7, 2017

The CPCB has said high moisture level in the air has trapped emission from local sources and hanging low over the city in the absence of wind.

"Total calm conditions, marked by the complete absence of wind has led to the situation. The moisture has trapped emissions from ground level sources," Dipankar Saha, CPCB's air lab chief, said.

According to private weather forecasting agency Skymet, wind from neighbouring Punjab and Haryana, where paddy stubble burning is in full swing, has started entering the city during the afternoon hours.

The CPCB also recorded 'severe' air quality in the neighbouring Noida and Ghaziabad.

The real-time pollution monitors displayed an alarmingly high concentration of PM2.5 and PM10, which are ultrafine particulates having the ability to enter the respiratory system and subsequently the bloodstream of humans and animals, causing harm.