Delhi’s air quality worsens yet again, enters ‘severe’ zone

According to the Central Pollution Control Board, the hourly Air Quality Index (AQI) was 416 at 7am on Thursday. The average 24-hour AQI was 370 on Wednesday

Delhi’s air quality worsened on Thursday to “severe” from the previous day’s “very poor” category even as the city was expected to get light rain or drizzle and record a minimum temperature of 13 degrees Celsius.

Low visibility due to smog at Vijay Chowk in New Delhi on Tuesday. (Sanjeev Verma/HT File photo)

According to the Central Pollution Control Board, the hourly Air Quality Index (AQI) was 416 at 7am. The average 24-hour AQI was 370 on Wednesday.

An AQI between zero and 50 is considered “good”, 51 and 100 “satisfactory”, 101 and 200 “moderate”, 201 and 300 “poor”, 301 and 400 “very poor”, and 401 and 500 “severe”.

Patna had the second-worst air quality on Thursday morning with an AQI of 294 at 7am and Chennai the best among 10 cities (AQI of 71 at 7am).

The Union earth science ministry’s System of Air Quality and Weather Forecasting And Research (SAFAR) said that Delhi’s AQI was in the “very poor” category on Thursday.

“The AQI today indicates ‘very poor’ air quality. Today (Thursday) and tomorrow (Friday) winds are likely to be calm reducing ventilation leading to a deterioration of air quality but within the same category. From December 3 (Friday) onwards winds are expected to increase dispersing pollutants but AQI is likely to remain in the very poor category. Low mixing layer height is preventing efficient dispersion of pollutants.”