Noida (UP), Nov 5 (PTI) The air quality worsened in Noida, Greater Noida, Ghaziabad, Gurgaon and Faridabad in the National Capital Region (NCR) on Thursday to reach 'severe' levels, which affects healthy people and seriously impacts those with existing diseases, according to a government agency.
Concentration of major air 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).
As per 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 Thursday was 464 in Ghaziabad, 457 in Greater Noida, 450 in Noida, 443 in Gurgaon and 416 in Faridabad, according to the CPCB's Sameer app.
It was 389 in Ghaziabad, 368 in Greater Noida, 345 in Noida, 331 in Faridabad and 290 in Gurgaon on Wednesday.
PM 2.5 was the prominent pollutant in these five satellite cities of Delhi, where the average AQI remained at 450 on Thursday, according to the app.
The CPCB states that an AQI in the 'severe' category affects healthy people and seriously impacts those with existing diseases.
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. PTI KIS KJ