NOIDA: The average air quality improved drastically to reach 'poor' level from 'severe' in Ghaziabad, Noida, Greater Noida, Faridabad and Gurugram, according to a 24-hour data issued by a government agency on Monday.
Presence of pollutants PM 2.5 and PM 10 also remained high in 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 Monday was 256 in Ghaziabad, 237 in Greater Noida, 225 in Noida, 296 in Faridabad and 226 in Gurugram, according to CPCB's Sameer app.
The CPCB states that an AQI in the poor category may cause breathing discomfort to people on prolonged exposure.
The average AQI on Sunday was 407 in Ghaziabad, 418 in Greater Noida, 405 in Noida, 404 in Faridabad and 359 in Gurugram.
The AQI for each city is based on the average value of all stations there. Noida, Faridabad, Ghaziabad have four stations each, while Gurugram has three and Greater Noida two, according to the app.