Air quality was “very poor” in several parts of Delhi on Wednesday morning, with the overall Air Quality Index at 309 around noon, according to SAFAR. This is worse than the index of 291 in the city on Tuesday evening. An index value between 301 and 400 is considered “very poor” and it is “severe” between 401 and 500.

At noon on Wednesday, the PM10 level, which is the presence of particles with diameter less than 10 microns, stood at 346.2 micrograms per cubic metre in the city. The overall PM2.5 level was 145.3 micrograms per cubic metre.

The Air Quality Index was the worst in Bawana locality, at 416 at noon, which is “severe”. The index was 388 in Anand Vihar, 350 in Jahangirpuri, 285 in Jawaharlal Nehru Stadium area, 295 at ITO, and 315 at Okhla.

On Monday, an emergency action plan to tackle poor air quality in Delhi came into force. This started with a ban on diesel generator sets. Measures also covering surrounding parts of the National Capital Region include mechanised sweeping of roads and deployment of traffic police to ensure smooth passage of traffic in vulnerable areas.

The measures are part of the Graded Response Action Plan, which was put in place in 2017 on the directions of the Supreme Court after high pollution levels in the National Capital Region in the winter of 2016.