Air quality in Delhi Wednesday continued to be in the “severe” category, as residents complained of burning eyes and itchy throats.
At 12 noon, the highest Air Quality Index (AQI) of 458 was recorded at Anand Vihar, but it was above the 400-mark in several locations, according to the National Air Quality Index maintained by the Central Pollution Control Board (CPCB).
AQI between 0-50 is considered “good”, 51-100 “satisfactory”, 101-200 “moderate”, 201-300 “poor”, 301-400 “very poor”, and 401-500 “severe”. Above 500 is “severe-plus emergency” category.
AQI this season in Delhi had been in the “very poor” category till Diwali, but hit “severe” levels on Tuesday.
According to the System of Air Quality and Weather Forecasting And Research (SAFAR), the major reason for the deteriorating air quality is the increased crop stubble burning in Punjab and Haryana. This was made worse by the bursting of firecrackers on Diwali.
The Centre of Science and Environment (CSE) on Tuesday said firecrackers on Diwali played an “overwhelming role” in bringing the AQI to severe levels. Their report said a 10-fold jump in the concentration of PM 2.5 — a major air pollutant — was noted between 5 pm and 1 am on Diwali due to bursting of firecrackers.
Delhi has seen windy weather over the past few days, which helps in dispersing pollution, but also brings in more pollutants from its northwest. On Tuesday, Delhi Chief Minister Arvind Kejriwal appealed “with folded hands” to Punjab and Haryana to take concrete steps against stubble burning to prevent the national capital from becoming a “gas chamber”.
In the NCR region, Noida is in as bad a condition as Delhi, while Gurugram fares marginally better. At 12 noon on Wednesday, the highest AQI recorded in Noida was 453, in sector 62. In Gurugram, the figure was 387, at NISE Gwal Pahari.
The AQI takes into account the concentration of chief pollutants in the air — particulate matter with a diameter less than 10 micrometres (PM10), PM 2.5, ozone (O3), nitrogen dioxide (NO2), sulfur dioxide (SO2), and carbon monoxide (CO).