Air quality plunged to “severe” levels in Ghaziabad, Noida, Greater Noida and Faridabad, while it was “very poor” in Gurgaon, according to 24-hour data released Thursday by a government agency.
PM 2.5 and PM 10 pollutants remained predominant in the air of Delhi’s five immediate neighbors, 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 “average”, 201 and 300 “bad”, 301 and 400 “very bad” and 401 and 500 “severe”.
The 24-hour average AQI at 4 p.m. Thursday was 429 in Ghaziabad, 410 in Greater Noida, 412 in Noida, 447 in Faridabad and 364 in Gurgaon, according to the CPCB’s Sameer app.
On Wednesday it was 388 in Ghaziabad, 398 in Greater Noida, 348 in Noida, 367 in Faridabad and 276 in Gurgaon.
On Tuesday it was 324 in Ghaziabad, 312 in Greater Noida, 278 in Noida, 260 in Faridabad and 213 in Gurgaon.
CPCB states that an AQI of the category “severe” affects healthy people and seriously affects those with existing illnesses, while “very poor” can cause respiratory illness with prolonged exposure.
The AQI for each city is based on the average value of all the stations there. Ghaziabad and Gurgaon have three such stations, while Noida, Greater Noida and Faridabad have two stations each, according to the app.