NEW DELHI: Local sources of pollution in Delhi and NCR mainly contribute to the poor air quality that plagues the national capital every winter. They need to be tackled on a priority basis, the Supreme Court-mandated Environment Pollution (Prevention and Control) Authority has said.“Incidents of external biomass burning cannot be ignored. These are worsening the pollution levels in Delhi-NCR. But biomass burning is contributing less than 10% to the pollution, which means local sources account for 90% of the pollution. Uttar Pradesh , Haryana and Delhi; all are to blame,” EPCA member Sunita Narain said on Monday.Track the pollution level in your city“Chimney and dust pollution as well as open burning of plastic and rubber scrap are major causes for concern,” the expert added.While chief minister Arvind Kejriwal has often blamed stubble burning in the neighbouring states for the deterioration in air quality in the city, SAFAR, the ministry of earth science's air quality and weather forecast service, has said that the share of stubble burning in the PM 2.5 concentration in Delhi has remained less than 10% so far.PM 2.5 stands for particulate matter less than 2.5 microns in diameter. They can be breathed deep into the lungs, and may even get into the bloodstream.The effect of stubble burning ranged from 0 to 9% between October 10 and October 13, revealed a SAFAR report released on Monday.“Delhi's air quality index (259) is at the higher end of the poor category. It touched the very poor category last night for a brief period, indicating the peak impact of stubble fires to a maximum of 8%,” it had said in the report.“The impact of biomass burning is going to be negligible soon due to the change in circulation pattern,” the SAFAR report said.EPCA also said that illegal godowns have come up on agricultural land in Bahadurgarh district of Haryana. They are burning waste that cannot be recycled, it added.“Plastic segregation and recycling are important for the city. The Delhi Development Authority has given land for it at Tikri Kalan and Ramky Enviro Engineers Limited lifts the waste that cannot be recycled for controlled burning in waste-to-energy plants,” Narain said.“The problem is that it is overflowing outside Tikri. There are illegal segregation units that burn the waste that cannot be recycled,” she said.Kejriwal had on Monday requested the Supreme Court and the National Green Tribunal to do something about stubble burning in neighbouring states.The Graded Response Action Plan to curb air pollution in Delhi-NCR came into force on Tuesday, rolling out stricter measures depending on the need to discourage private vehicles on roads, use of diesel generators, and closing brick kilns and stone crushers.