According to the System of Air Quality and Weather Forecasting and Research (SAFAR), nine of the 10 monitoring stations across Delhi recorded "very poor" air quality, with pollutant PM2.5 ranging between 313-366 units.
The international permissible limit for PM2.5 is 25 microgram per cubic metre while for India, it is 60. For PM10, the permissible limit is 100.
In Delhi, Noida and Gurugram, air quality deteriorated in the past 24 hours, with the air quality index (AQI) recorded at "very poor". The index value was 344 in Delhi, 363 in Noida, and 318 in Gurugram. On Tuesday, the AQI at these three places was 309, 315, and 345 respectively.
Today, air quality at Ghaziabad (NCR) was worse than post-Diwali (recorded on October 20) level, and was described as severe by the Central Pollution Control Board. The AQI in Ghaziabad was 425 today, as compared with 412 on October 20.
Satellite images from the National Aeronautics and Space Administrations' show stubble-burning reached an all-time high with both Punjab and Haryana marked in red (depicting fire).
Stubble-burning was part of the pollution control agenda of the Environment Pollution (Prevention and Control) Authority (EPCA), which a day before Diwali implemented "very poor" and "severe" categories of its Graded Response Action Plan (GRAP) -- which includes more strict measures -- to curb air pollution in Delhi and adjoining areas.
"It (stubble-burning) was an action point, but nothing much was done against stubble- burning as the National Green Tribunal is already involved," EPCA member Usmaan Naseem told IANS.
According to EPCA officials, state authorities (Punjab, Haryana, Rajasthan and Uttar Pradesh) are supposed to keep a check on stubble-burning, as toxic smoke along with weather conditions and wind speeds, impact air quality in Delhi-NCR.
The unabated stubble-burning in Punjab and Haryana, estimated to be around 35 million tonnes, was banned by the NGT in November 2015. However, farmers continued to burn paddy straw.
"Air pollution is set to increase. People will complain of heaviness in breathing towards morning and evening hours. The north-westerly winds from Punjab and Haryana are slowing down in Delhi, and this will continue for some days," Mahesh Palawat, director of private weather forecast agency Skymet, told IANS.