Delhi breathed almost ‘clean’ air on Wednesday, after a gap of 50 days, as the Air Quality Index (AQI) was recorded in the ‘moderate’ category. The 24-hour average Air Quality Index (AQI) of the city was recorded at 178 at 4 pm, registering an improvement from 268 on Tuesday. Many people are hoping to get relaxation from the GRAP IV restrictions when the matter comes up for hearing in the Supreme Court on Thursday.
Earlier, the AQI was recorded in the ‘moderate’ category with a reading of 198 on October 15. However, the AQI had deteriorated and shifted to the ‘poor’ category the following day, according to Central Pollution Control Board data. Najafgarh was the least air polluted area with an air quality index of 112 while Mundka was the most polluted area with an AQI 286.
Speaking about the improved air quality, an official of the India Meteorological Department said strong surface winds were forecast in the city on Wednesday. The winds will blow till December 7, when a new western disturbance is expected, which will lead to moderate fog starting December 8.
Of the 38 air quality monitoring stations in the city, only Sri Aurobindo Marg reported air quality in the ‘very poor’ category on Wednesday, while eight others showed air quality in the ‘poor’ category. The remaining reported ‘moderate’ air quality, according to the Central Pollution Control Board (CPCB).
The primary pollutants on Wednesday were PM2.5, with levels recorded at 66.8 µg/m³ at 4 pm, while PM10 levels were 149.5 µg/m³ at the same time. These fine particles pose significant health risks as they can penetrate deep into the lungs and enter the bloodstream.
Meanwhile, the Decision Support System (DSS), the primary tool used to assess and estimate the sources of pollution in Delhi, has not been updated since Friday. A Commission for Air Quality Management (CAQM) official stated that the DSS is still undergoing development and has not yet been fully operationalised. "An evaluation committee reviewed the system and found that its data and accuracy did not meet the terms of reference established for the model.
Additionally, it was observed that some of the data and the emissions inventory being used were outdated," the official explained, seeking anonymity.
According to the Centre for Research on Energy and Clean Air, (CREA) report on air pollution, Delhi ranked as the most polluted city in India in November 2024, recording a monthly average PM2.5 concentration of 249 µg/m³, surpassing the daily NAAQS limit of 60 µg/m³ 100% of the days in the month. Delhi recorded 20 days in the ‘Very Poor’ (121-250 µg/m³) category and 10 days in the ‘Severe’ (>250 µg/m³) category. The November average is 2.2 times higher than the October average of 111 µg/m³, when there were 5 days in the ‘Satisfactory’ category, 8 days in the ‘Moderate’ category, 4 days in the ‘Poor’ (91-120 µg/m³) category, and 14 days in the ‘Very Poor’ (121-250 µg/m³) category.
In November 2024, the number of cities with ‘Good’ (0-30 µg/m³) air quality dropped significantly to 32, compared to 79 in October. Meanwhile, cities with ‘Satisfactory’ (31-60 µg/m³) air quality decreased from 135 in October to 77 in November. The number of cities experiencing ‘Moderate’ (61-90 µg/m³) air quality rose to 86 in November, up from 44 in October. There was also a notable increase in cities with ‘Poor’ (91-120 µg/m³) air quality, rising from 5 in October to 50 in November, and 23 cities recorded ‘Very Poor’ (121-250 µg/m³) air quality, compared to 0 in the previous month.
