NEW DELHI: Delhi’s air quality turned “severe” on Diwali with stubble burning accounting for 32 per cent of the city’s PM2.5 pollution and calm winds worsening the situation as they allowed accumulation of pollutants, weather officials said.
The Ministry of Earth Sciences’ air quality monitor, SAFAR, said, “Even a small increase in local additional emissions is likely to have significant deterioration impact on Sunday and Monday.” It said peak levels of PM10 and PM2.5 are expected between 1 am and 6 am in case of additional internal emissions.
Earlier, it had said that the PM2.5 concentration in Delhi on Diwali is likely to be the “lowest” in the last four years if no firecrackers are burnt.
The city recorded an overall AQI of 414 on Saturday, which falls in the “severe” category. The 24-hour average AQI was 339 on Friday and 314 on Thursday.
Delhi recorded a 24-hour average AQI of 337 on Diwali last year (October 27), and 368 and 400 in the next two days. Thereafter, pollution levels remained in the “severe” category for three days on the trot.
In 2018, the 24-hour average AQI (281) on Diwali was recorded in the “poor” category. It deteriorated to 390 the next day and remained in the “severe” category on three consecutive days thereafter.
In 2017, Delhi’s 24-hour average AQI on Diwali (October 19) stood at 319. It, however, slipped into the “severe” zone the next day.
This time, the India Meteorological Department has said that a fresh western disturbance is likely to increase the wind speed and improve the air quality in Delhi-NCR post Diwali.
Light rain is likely on Sunday under the influence of a western disturbance. It is still to be seen if it is enough to wash away pollutants, Kuldeep Srivastava, the head of the IMD’s regional forecasting centre, said.
“However, Delhi-NCR’s air quality is likely to improve post Diwali due to an expected increase in the wind speed on Sunday,” he said. — PTI