After a month, AQI 'satisfactory' in Ghaziabad, 'moderate' in Noida

After a month, the air quality in Ghaziabad reached satisfactory level while it was recorded as moderate in Noida, Greater Noida, Faridabad and Gurgaon following a spell of mild rain in NCR, according to data issued by a government agency on Friday.

Pollutants PM 2.5 and PM 10, though, remained in the air 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 pmon Friday was 91 in Ghaziabad, 114 in Noida, 144 in Greater Noida, 105 in Faridabad and 160 in Gurgaon, according to CPCB's Sameer app.

On Thursday, it was 338 in Ghaziabad, 322 in Noida, 312 in Greater Noida, 308 in Faridabad and 303 in Gurgaon.

The CPCB states that an AQI in thesatisfactory category causes minor breathing discomfort to sensitive people, while moderate may lead to breathing discomfort to the people with asthma, lung and heart diseases.

The last time the average air quality was recorded in satisfactory and moderate levels was on January 5, after which the AQI has been oscillating in poor, very poor and severe categories, according to the CPCB.

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.