NEW DELHI: The share of stubble burning in Delhi’s PM2.5 pollution rose to 23 per cent on Tuesday, the maximum so far this season, according to a central government air quality monitoring agency. It was 16 per cent on Monday, 19 per cent on Sunday and nine per cent on Saturday.
The number of farm fires in neighbouring states was 1,943 on Monday, the highest so far this season, according to the Ministry of Earth Sciences’ air quality monitor, SAFAR.
“Stubble burning share in Delhi PM2.5 concentration was 23 per cent on Tuesday due to favourable transport-level wind direction and speed,” it said. Meanwhile, pollution levels reduced marginally in the national capital on Tuesday morning but the air quality was still recorded in the ‘very poor’ category.
A senior scientist at the India Meteorological Department said the air quality index (AQI) is likely to improve with the wind speed picking up. Calm winds and low temperatures trap pollutants close to the ground, while favourable wind speed help in their dispersion.
The city recorded an AQI of 335 at 10 am. The 24-hour average AQI was 353 on Monday. It was 349 on Sunday, 345 on Saturday and 366 on Friday. An AQI between 0and 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’.
According to the Ministry of Earth Sciences’ air quality monitor, SAFAR, the wind direction and speed were favourable for the transport of pollutants from farm fires in Punjab, Haryana and neighbouring regions. It, however, said an improvement in local wind speed will counter the effect. Air pollution in Delhi is a year-round problem, which can be attributed to unfavourable meteorological conditions, farm fires in nearby state and local sources of pollution.