NEW DELHI: After three “severe” air days on the trot, Delhi’s air quality improved slightly to the “very poor” category on Friday. The city’s average air quality index (AQI) was 391. The 24-hour average AQI was 423 on Thursday. It was 433 on Wednesday and 418 on Tuesday.
The air quality is expected to improve marginally by Sunday as wind speed picks up under the influence of the western disturbance, according to the weather department. The air quality will dip again, starting Monday due to predicted high humidity, low wind speed and temperatures.
Other cities in the National Capital Region also recorded air quality levels in the ‘very poor’ category, according to a 24-hour data issued by a government agency on Friday. Presence of pollutant PM 2.5 and PM 10, though, remained high in the five immediate neighbours of Delhi, according to the air quality index (AQI) maintained by the Central Pollution Control Board (CPCB).
The average 24-hour AQI at 4 pm on Friday was 391 in Ghaziabad, 376 in Greater Noida, 386 in Noida, 328 in Faridabad and 302 in Gurgaon, according to CPCB’s Sameer app. 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”.
The CPCB states that an AQI in the ‘very poor’ category may cause respiratory illness on prolonged exposure while ‘severe’ affects even healthy people and seriously impacts those with existing diseases.