Air quality deteriorates across Delhi-NCR

New Delhi: After a brief respite, the air quality of the national capital and regions around it worsened on Wednesday again, with pollution levels slipping back to “severe” or “severe-plus” category in many areas.

As the pollution level went from “poor” to “very poor” over the past 24 hours due to a drop in air quality and a sharp rise in moisture-gripping effluents, the Air Quality Index (AQI) of Delhi on Wednesday was recorded at 347 as against 256 on Tuesday.

Based on different types of effluents, including particles and gases, the AQI is measured on a scale of 0 to 500, with values above 300 rated as very poor and above 400 considered as severe.

The AQI on Wednesday was 351 for Faridabad (224 on Tuesday), 263 in Gurugram (114 on Tuesday), 434 in Ghaziabad (329 on Tuesday) and 214 for Noida (329 on Tuesday).

At 7.00 p.m., the major pollutant PM2.5, or particles with diameter less than 2.5 micrometres, was 231 units in Delhi as against 132 units on Tuesday. Across NCR, the PM2.5 was 223 units as against 122 units on Tuesday.

While on Tuesday none of the 25 monitored regions across NCR fell under severe category, five areas — Anand Vihar, Delhi Technical University, Bhiwadi, Faridabad and Vasundhara in Ghaziabad — saw severe-plus air quality, with PM2.5 ranging above 300 units.

Air quality was severe or PM2.5 above 250 units at ITO in central Delhi, Delhi University North Campus, Punjabi Bagh, R.K. Puram, Shadipur, Siri Fort and Sector 125-Noida.

According to experts, the pollution levels will remain high till Friday.