Delhi’s Air Quality Deteriorates, AQI Hits 227 in First ‘Poor’ Reading of the Season
Delhi recorded its first ‘poor’ air quality reading of the season on Wednesday morning, with the Air Quality Index (AQI) reaching 227 at 7:05 am, according to official data.
Data from the Central Pollution Control Board (CPCB), analysed by the HT AQI Dashboard, showed that the city’s air quality deteriorated overnight. The decline followed Dussehra celebrations on Tuesday evening, when effigies were burnt and firecrackers were burst across several parts of the city, adding to emissions from Durga Puja festivities.
The deterioration also coincided with reports of farm fires in Punjab and Haryana. According to NASA satellite data, 182 farm fires were detected in the two states during the three days leading up to October 20. Since October 1, the satellite has recorded 397 such incidents, compared with 523 during the corresponding period last year.
However, the satellite passes over the region at around 1:30 pm, while most stubble-burning activities currently take place later in the day. As a result, the recorded figures may significantly underestimate the actual number of farm fires. A lower count, therefore, does not necessarily indicate a reduction in stubble burning.
According to CPCB classifications, an AQI of 0–50 is considered ‘good’, 51–100 ‘satisfactory’, 101–200 ‘moderate’, 201–300 ‘poor’, 301–400 ‘very poor’ and 401–500 ‘severe’.
Delhi last recorded ‘poor’ air quality on July 12 and 13, when the AQI stood at 261 and 246, respectively.
The CPCB’s hourly data showed that Delhi’s AQI stood at 227 at 7 am on Wednesday, an increase of 48 points from 179 recorded in Tuesday’s 4 pm bulletin.
The AQI crossed the 200-mark, entering the ‘poor’ category, at 2 am on Wednesday and remained above that threshold in every subsequent hourly reading.
For most of October, Delhi’s air quality remained in the ‘moderate’ category, with brief improvements following rainfall on October 12 and 16. The AQI was recorded at 187 on October 18, 139 on October 19 and 179 on October 20.
Data from 56 of Delhi’s 59 air quality monitoring stations showed that two stations recorded ‘very poor’ air quality. Jahangirpuri registered an AQI of 308, while Pusa recorded 314.
At 16 monitoring stations, including Anand Vihar, the air quality remained in the ‘moderate’ category.
Falling temperatures and changes in wind speed have also contributed to the deterioration in air quality. These conditions affect the dispersion of pollutants, allowing them to accumulate in the atmosphere and worsening pollution levels across the capital.
