The average air quality stayed "severe" in the national capital region of Ghaziabad, Noida, Greater Noida and Faridabad while it remained "very poor" in Gurgaon, a government agency data on air pollution for the last 24 hours said on Saturday.
Presence of particulate matters, PM 2.5 and PM 10, remained high in Delhi's five neighbourhood, revealed 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 462 in Ghaziabad, 450 in Greater Noida, 448 in Noida, 415 in Faridabad and 336 in Gurgaon, according to CPCB's Sameer app.
The index has a maximum limit of 500.
The CPCB states that an AQI in the "severe" category affects healthy people and seriously impacts those with existing diseases while "very poor" may lead to respiratory illness on prolonged exposure.
The average AQI on Friday was 470 in Ghaziabad, 434 in Greater Noida, 455 in Noida, 421 in Faridabad and 376 in Gurgaon.
On Thursday it was 343 in Ghaziabad, 394 in Greater Noida, 369 in Noida, 344 in Faridabad and 317 in Gurgaon.
The AQI for each city is based on the average value of all stations there. Noida, Faridabad, Ghaziabad have four stations each, while Gurgaon has three and Greater Noida two, according to the app.
