The average air quality stayed "moderate" in Noida but dipped to "poor" in Greater Noida, Ghaziabad and Faridabad, while it dropped to "moderate" from "satisfactory" in Gurgaon, according to a 24-hour data issued by a government agency on Wednesday.
Pollutants PM 2.5 and PM 10 although remained prominent 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).
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 Wednesday was 234 in Ghaziabad, 239 in Greater Noida, 200 in Noida, 203 in Faridabad and 175 in Gurgaon, as per the CPCB''s Sameer app.
On Tuesday, it was 148 in Ghaziabad, 120 in Greater Noida, 149 in Noida, 138 in Faridabad and 83 in Gurgaon.
On Monday, it was 168 in Ghaziabad, 134 in Greater Noida, 152 in Noida, 179 in Faridabad and 65 in Gurgaon.
The CPCB states that an AQI in the "moderate" may lead to breathing discomfort to the people with lungs, asthma and heat diseases, while "poor" may cause breathing discomfort to most people on prolonged exposure.
The AQI for each city is based on the average value of all stations there.
Ghaziabad and Gurgaon have three such stations while Noida, Greater Noida and Faridabad have two stations each, according to the app.
