The quality of air in the Delhi National Capital Region and across the Indo-Gangetic belt plummeted on Monday night and continues to remain very poor as stagnant winds are preventing particulate matter from being flushed out of the region, official agencies and experts said.
Southern India, on the other hand, is enjoying a spell of good air partly driven by settling of pollutants due to northeast monsoon showers, which while causing floods in parts of Tamil Nadu have also helped clear the air.
The same phenomenon is however translating into worse air quality for north India, D Saha at the Central Pollution Control Board's Air Laboratory said, as Delhi woke to a white cover of fog this morning.
''Moisture from the south is entering the north and trapping pollutants near the surface,'' Saha said.
According to the CPCB, individual stations in Delhi NCR recorded Air Quality Index (AQI) as high as 446 at 9.30am. Out of 19 monitoring stations in NCR, 12 recorded severe air quality.
Saha also said what Delhiites experienced this the morning was fog and not smog because of low levels of sulphur dioxide.
At least 20 flights were reported to be affected by poor visibility at the Delhi airport.
While an Air Quality Index (AQI) between 0-50 is considered good, Delhi's average AQI was 411 at 9am on this morning, which is severe. According to the India Meteorological Department, visibility also took a plunge and it was way below 200 metres.
In Uttar Pradesh's Moradabad, air pollution levels are threatening to go off the charts with AQI of 478, as per data from the CPCB.
Delhi Chief Minister Arvind Kejriwal has blamed the rising pollution levels to crop burning in adjoining states. In a tweet, he said: "We have to find a solution to crop burning in adjoining states."
The Indian Medical Association (IMA) has also written to the Delhi government advising it to stop outdoor activities and sports at schools in the morning. Chief minister Kejriwal has even suggested cancelling schools till the air quality improves.
Half-marathon under cloud
The IMA has also asked Kejriwal to cancel the Airtel Delhi Half Marathon on 19 November due to 'high level of air pollution'.
In two letters to deputy chief minister Manish Sisodia, IMA National President Dr KK Aggarwal and the honorary secretary general Dr RN Tandon said that school children are "especially at risk", with air quality ranging from 'poor' to 'severe'.Earlier, half marathon title sponsor Airtel had threatened to discontinue its decade-long alliance with the event if the rising concerns of air pollution in the capital are not addressed.
"Air pollution poses serious health risks and it is important that these concerns are addressed urgently and appropriately by the authorities for Airtel to continue associating with the event next year and beyond," the telecom major said in a statement.
Another major factor for the poor air quality is crop burning in the states of Punjab, Haryana and Uttar Pradesh, that will persist for the entire winter season.
Noida and Ghaziabad also witnessed hazardous levels of pollution in the past 24 hours and it is unlikely to get better.
Moradabad is the hub for waste recycling, in particular electronic waste, and pollutants from improper disposal practices feed into poor air quality.
The still air has made the problem worse with PM 2.5 levels recording a sudden jump to over 600 µg/m3 (micrograms per metre cube), over 10 times the prescribed limit. Exposure to these levels of pollution over a long time causes respiratory problems especially for people with lung and heart disease.
A majority of the 18 pollution monitors installed by the Central Pollution Control Board (CPCB), Delhi Pollution Control Committee and the Indian Meteorological Department read 'severe'.
The worst reading was at Shadipur, West Delhi, where the AQI was 448, while Anand Vihar's AQI was at 422, up from 411 at 10 pm on Monday night. RK Puram, another heavily polluted spot in the city was at 414 and Punjabi Bagh at 420.
Mathura Road was also at 441, which is one of the highest in the city.