The average air quality slipped to reach “severe” levels in Ghaziabad while it was recorded as “very poor” in Noida, Greater Noida, Gurgaon and Faridabad, according to data issued by a government agency on Saturday.
Pollutants PM 2.5 and PM 10 also remained in the air of the five immediate neighbours of Delhi, according to the air quality index (AQI) maintained by the Central Pollution Control Board (CPCB).
According to the index, 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 average 24-hour AQI at 4 pm on Saturday was 401 in Ghaziabad, 386 in Noida, 363 in Greater Noida, 362 in Faridabad and 310 in Gurgaon, according to CPCB’s Sameer app.
On Friday it was 372 in Ghaziabad, 363 in Noida, 352 in Greater Noida, 326 in Faridabad and 347 in Gurgaon.
The CPCB states that an AQI in the “severe” category affects healthy people and seriously impacts those with existing diseases, while “very poor” may cause respiratory illness to people on prolonged exposure.
The AQI for each city is based on the average value of all monitoring stations there. Ghaziabad, Gurgaon and Noida have four such stations while Greater Noida and Faridabad have two stations each, according to the app.