The System of Air Quality and Weather Forecasting And Research (SAFAR) has predicted Delhi's overall air quality is to remain in the 'poor' to the lower end of 'very poor' category until the morning of October 24. Transport-level winds from Punjab, Haryana and Uttar Pradesh towards Delhi will pick up from October 24 and, in all likelihood, will bring significant stubble-related emissions to Delhi, SAFAR said. According to a research study by the Centre for Research on Energy and Clean Air (CREA) the air quality in the national capital exceeds the National Ambient Air Quality Standards (NAAQS) during the winters, stubble burning remains a “significant contributor” to Delhi's unbreathable air in October and November. The city's 24-hour average AQI was recorded in the 'poor' category at 265 on Saturday as residents flouted the ban on firecrackers in parts of the national capital ahead of Diwali, according to Central Pollution Control Board's (CPCB) data.
"If stubble burning increases gradually, which is likely, its share in Delhi's PM2.5 (based on the average temporal variability of fire counts in the previous years) is likely to be 5 per cent on the October 23, 8 per cent on October 24 and 16 to 18 per cent on October 25," SAFAR's predictions said.
"Adverse weather conditions may bring firecracker-related pollution from surrounding regions of Delhi (outside NCT) and with 15 to 18 per cent stubble burning contribution, the AQI is predicted to touch the upper end of 'very poor' to lower end of 'severe' on October 25 (without emission from firecrackers in Delhi)," the predictions said.
SAFAR further predicted that in case there was emission from firecrackers, along with other factors, the AQI would worsen to 'severe' on Diwali (October 23) and might continue to remain the same for the next two days (October 24 and October 25)."Air quality might improve slightly on October 26 evening onwards to the lower end of 'very poor' category as surface winds will pick up on October 26 and stubble transport level winds will slow down," the predictions said.
CREA in its study said that the causes behind Delhi's unbreathable air include a “lack of emission control technologies” in major sources of pollution, vehicular emissions, and episodic events of stubble burning, making the city's air quality extremely hazardous.
The study further stated that apart from the monsoon months (July-September), Delhi's ambient air pollution is "significantly higher" than the annual and daily PM2.5 standards set by the Central Pollution Control Board (CPCB) in India.
CREA suggests that the air quality in the national capital deteriorates between the last week of October to mid-November and that the worsening air quality can be attributed to stubble burning for 15-20 days (between the last week of October and mid-November) and firecrackers around the Diwali festival celebrations in addition to the existing sources.