A significant improvement is likely in the national capital's air quality over the next two days, a central government air quality monitoring agency said on Friday. The Ministry of Earth Sciences' air quality monitor, SAFAR, said that the share of stubble burning in Delhi's PM2.5 pollution was 19 per cent on Friday. It was 36 per cent on Thursday, the maximum so far this season, 18 per cent on Wednesday, 23 per cent on Tuesday, 16 per cent on Monday, 19 per cent on Sunday and nine per cent on Saturday.
The number of farm fires in neighbouring states dropped from 2,912 on Wednesday – the highest so far this season – to 1,143 on Thursday.
Delhi's overall air quality index (AQI) has improved marginally as predicted and remains in the high end of the very poor category, it said.
The wind speed is expected to pick up and the improved ventilation is likely to influence air quality positively, SAFAR said.
A significant improvement is predicted by November 1 and the air quality is likely to slip back into the “poor” category, it said.
Delhi's air quality entered the “severe” category for a brief period on Thursday, for the first time since January, as calm winds and low temperature allowed the accumulation of pollutants amid a spike in farm fires.
On Friday morning, Delhi's air quality was recorded in the “very poor” category.
The city recorded an AQI of 381 at noon. The 24-hour average AQI was 395 on Thursday. It was 297 on Wednesday, 312 on Tuesday, 353 on Monday, and 349 on Sunday.
Several monitoring stations, including at Shadipur (417), Patparganj (406), Bawana (447) and Mundka (427), recorded air quality in the “severe” category.
An AQI between 0 and 50 is considered 'good', 51 and 100 'satisfactory', 101 and 200 'moderate',201 and 300 'poor', 301 and 400 'very poor', and 401 and 500 'severe'.
(With inputs from PTI)