Air quality 'poor' in Ghaziabad, Noida; moderate in Faridabad, Gurgaon

The air quality was recorded in the "poor" category in Ghaziabad and Greater Noida and in the "moderate" zone in Noida, Faridabad and Gurgaon, according to data issued by a government agency on Saturday.

Pollutants PM 2.5 and PM 10 also remained high 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).

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 4pmon Saturday was 213 in Ghaziabad, 204 in Greater Noida, 182 in Noida,169 in Faridabad and 177 in Gurgaon, according to CPCB's Sameer app.

On Friday it was 276 in Ghaziabad, 301 in Greater Noida, 250 in Noida, 268 in Faridabad and 273 in Gurgaon.

The CPCB states that an AQI in the"poor" category may lead to breathing discomfort to most people on prolonged exposure, while an air quality in the "moderate" zone may cause breathing discomfort to people with asthma, lungs and heart diseases.

The AQI for each city is based on the average value of all monitoring stations there. Ghaziabad, Gurgaon and Noida have four such stations while Greater Noida and Faridabad have two stations each, according to the app.