Delhi Weather: Delhi government attributed dip in air quality to stubble burning in neighbouring states

The national capital witnessed a slight decrease in pollution levels on Thursday, recording its overall air quality index at 276, but the situation is predicted to deteriorate sharply over the weekend due to "significant" stubble burning.

Ten out of the 37 air quality monitoring stations in Delhi recorded Air Quality Index (AQI) in the "very poor" category. On Wednesday, the city's overall AQI stood at 304.

On Thursday, the AQI at DTU-Delhi, Sirifort, Jahangirpuri, Rohini, Vivek Vihar, Narela, Wazirpur, Bawana, Mundka and Anand Vihar was 320, 302, 301, 310, 305, 315, 311, 328, 303 and 304 respectively.

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.

The Centre-run System of Air Quality Forecasting And Research (SAFAR) said stubble burning incidents in Haryana, Punjab, and nearby border regions have shown an "increasing trend" over the last three days.

Additionally, a few new fires have been observed over western Uttar Pradesh.

It said the share of stubble burning to Delhi's PM2.5 concentration was eight per cent on Thursday. It is predicted to increase to 10 per cent on Friday and to 18 per cent on Saturday.

SAFAR also said the reason for deterioration of air quality at present is the "gradual change in weather conditions -- slow surface winds and cooling -- towards unfavourable side".

"Under the influence of an approaching western disturbance, a slight increase in wind speed is expected for Friday only. Under this condition, a marginal improvement in Delhi's AQI is predicted for Friday," it said.

Thereafter, by October 19, rapid deterioration of air quality is predicted as there is "high probability of significant stubble intrusion", SAFAR said.

The period between October 15 and November 15 is considered critical as maximum number of stubble burning incidents take place in this span in Punjab and adjoining states and is one of the main reasons for alarming spike in pollution in Delhi-NCR.

Despite a ban on stubble burning in Punjab and Haryana, farmers continue to defy it amid lack of financial incentives.

State governments are providing 50 to 80 per cent subsidy to farmers and cooperative societies to buy modern farm equipment for in-situ management of paddy straw and running a massive awareness campaign against stubble burning.

The Delhi government had on Wednesday attributed the dip in the air quality to rampant stubble burning in neighbouring states.

"Air quality in Delhi has been good or moderate for the last 7-8 months, but they (pollution levels) have starkly gone up now... Clearly, the sudden spike in pollution is a result of smoke coming from outside," a government statement had said.

On Thursday, it said that real time data to determine the contribution of local and non-local sources, including dust and stubble burning, to air pollution in the national capital region will be available from April next year.

"We have tied up with Washington University and a centre has been set up near India Gate. Daily basis sample collection is going on since March.

"The base data of Delhi air pollution in the last one year will be ready from April 1 next year. We will be able to tell the degree of air pollution due to specific sources," he said at a press conference.

Mr Kejriwal said it is wrong to blame the people of Delhi for air pollution in the city and stressed on the need to tackle stubble burning in a determined manner, which he claimed was not being done presently.

His statement came close on the heels of pollution watchdog EPCA member Sunita Narain saying that local sources of pollution were the primary reason for Delhi's deteriorating air quality.

On Thursday, Ms Narain tweeted, "It is not that local pollution has increased, it is that weather has turned adverse and so, air pollution is again on the rise. If we keep focusing on the external reasons, we will not fix our problems."