Delhi remained blanketed by a thick haze with its air quality dropping further, largely due to the heavy load of smoke from stubble burning in neighbouring Haryana and Punjab, according to government agencies.
Weather experts said the problem aggravated due to unfavourable wind speed that lead to accumulation of pollutants. A relief is likely on the weekend, they said.
The city’s pollution levels peaked at 2 am, touching the 423 mark. The overall air quality index (AQI) oscillated between 410 and 420 during the day, according to data from the Central Pollution Control Board.
Twenty-seven of the 37 air quality monitoring stations across Delhi recorded the AQI in the “severe” category. Anand Vihar was the most polluted area in the capital with an AQI of 464 and Wazirpur following with an AQI of 462.
NSIT, Dwarka, was the least polluted with an AQI of 355.
Pollution levels in the satellite towns of Ghaziabad (478), Greater Noida (440), and Noida (451) were equally worse.
An AQI between 0-50 is considered good, 51-100 satisfactory, 101-200 moderate, 201-300 poor, 301-400 very poor, and 401-500 severe. Above 500 is severe-plus emergency category.
According to the Ministry of Earth Sciences’ air quality monitor SAFAR, the share of stubble burning in Delhi’s pollution has risen to 35 per cent, the season’s highest, and the hazardous haze shrouding the city on Wednesday can be “purely” attributed to it.
Extremely calm surface winds on Tuesday night aggravated the problem, it said.
Northwesterly winds, which are favourable for plume transport, will continue to blow in the region for another two days, it predicted.
A marginal improvement in the air quality is predicted on Thursday due to an expected increase in wind speed which will help disperse pollutants faster.
On Thursday, the share of stubble burning in Delhi’s pollution is predicted to be 27 per cent. It was 25 per cent on Tuesday.