Delhi's air quality 'severe' again

Delhi's air quality turns "severe" again with slow wind speed and dip in temp. AQI at 401. 24-hr avg. AQI at 390. Centre removed stringent curbs due to drop in pollution. Vehicular emissions (38%) and secondary inorganic aerosols (25-35%) major contributors. Biomass burning (21%) also a factor. Pollution levels likely to oscillate in "very poor" to "severe" in next 5-6 days.

Air quality in Delhi turned “severe” again on Friday with a dip in temperatures and slow wind speed at night allowing accumulation of pollutants.

The city's Air Quality Index (AQI) stood at 401 at 8 a.m.

Delhi has been witnessing a gradual increase in AQI levels after a marginal improvement on Sunday.

The 24-hour average AQI, recorded at 4 pm every day, was 390 on Thursday, 394 on Wednesday, 365 on Tuesday, 348 on Monday and 301 on Sunday.

The increase in AQI levels comes after the Centre on Saturday removed stringent curbs, including a ban on construction work related to linear projects and the entry of polluting trucks in Delhi, following a drop in pollution levels due to a favourable wind speed and direction.

Neighbouring Ghaziabad (386), Gurugram (321), Greater Noida (345), Noida (344) and Faridabad (410) also recorded "very poor" to "severe" air quality.

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”, 401 and 450 “severe” and above 450 “severe-plus”.