Delhi recorded its worst air quality in 287 days on Tuesday, with the Air Quality Index (AQI) settling at 350 and 10 monitoring stations reporting severe pollution levels. The last time the national capital recorded a higher AQI was on January 20, when the index stood at 378.
Of the 57 air quality monitoring stations in the city, 10 recorded severe air quality, 35 reported very poor levels and 12 were in the poor category. Jahangirpuri recorded the worst air quality, with an AQI of 462, placing it in the severe category.
According to the Central Pollution Control Board (CPCB), an AQI of zero to 50 is classified as good, 51 to 100 as satisfactory, 101 to 200 as moderate, 201 to 300 as poor, 301 to 400 as very poor, and 401 to 500 as severe.
PM2.5 was the most prominent pollutant in Delhi. These fine particulate matter particles, measuring 2.5 micrometres or less in diameter, can penetrate deep into the lungs and enter the bloodstream, posing significant health risks.
The Air Quality Early Warning System for Delhi has forecast that air quality is likely to remain in the very poor category from November 4 to 6. The outlook for the next six days suggests that pollution levels could remain in the very poor to severe categories.
Delhi was brought under Stage II of the Graded Response Action Plan (GRAP) on Monday after its AQI deteriorated to the very poor category, settling at 324 and marking the first such day of the season.
The Decision Support System (DSS) estimated that stubble burning accounted for 15.3 per cent of Delhi's pollution, while transport emissions contributed 15.8 per cent.
Other local sources included energy production (1.2 per cent), industries in Delhi and the periphery (3 per cent), waste burning (1.4 per cent), construction activities (2.2 per cent), road dust (1.2 per cent), residential sources (3.9 per cent) and other sectors (1 per cent).
Among neighbouring National Capital Region districts, Jhajjar contributed 8.8 per cent, Gurugram 4.1 per cent, Sonipat 2.6 per cent, Rohtak 2.5 per cent and Mewat 2 per cent.
Satellites detected 219 farm fire incidents across six states on November 2, including 98 in Punjab, 67 in Rajasthan, 48 in Madhya Pradesh, four in Uttar Pradesh and two in Haryana.
No crop residue-burning incidents were detected in Delhi or Uttarakhand, according to data from the Consortium for Research on Agroecosystem Monitoring and Modelling from Space (CREAMS) Lab, Division of Agricultural Physics, ICAR-Indian Agricultural Research Institute.
A total of 3,535 farm fire incidents were detected across the six states between September 15 and November 2. Punjab accounted for the highest number, with 1,612 incidents, followed by Rajasthan (738), Madhya Pradesh (614), Uttar Pradesh (349), Uttarakhand (176), Haryana (44) and Delhi (two).
The stubble-burning season runs from September 15 to November 30. Delhi recorded its first stubble-burning incident of the season on September 19 and the second on October 24.
(With inputs from PTI)