The air quality of Delhi deteriorating again by Saturday evening. (File)
Even three days after Diwali, pollutants from fireworks, stubble burning and local sources continued showing their effect with Delhi-NCR still suffering "severe" air quality on Saturday.
Despite showing some improvement from a severe-plus to severe in the last 24 hours, the air quality of Delhi-NCR began deteriorating again by Saturday evening with a rise in pollutants.
The Air Quality Index (AQI) of Delhi at 4 p.m. was 401, while by 6 p.m. it dipped to 406 -- both considered "severe". Delhi's AQI on Friday at 4 p.m. was 423.
Unfavourable meteorological conditions like very low wind speed and lower temperature are stopping PM2.5 and PM10, or particles with diameter less than 2.5 and 10 mm, from dispersing.
The average concentration of PM2.5 and PM10 in Delhi was 269 and 424 microgrammes per cubic metres at 4 p.m., which hiked to 275 and 432 units at 6 p.m. Meanwhile the PM2.5 and PM10 concentration across 49 areas of NCR was 256 and 409 units at 4 p.m., which increased to 261 and 416 units by 6 p.m.
The weather analysts expect a marginal improvement from Monday onwards.
"Currently Delhi is receiving very calm winds from East and South East direction, which are not enough to disperse the pollutants and are getting calmer during night. Situation may improve from Monday though," said Mahesh Palawat, director, private weather agency Skymet.