Air quality deteriorated in the national capital with rise of pollutants. Stubble burning in neighbouring states is said to be among major reasons for pollution. Speaking to ANI, head and scientist of Regional Meteorological Centre in Delhi, Dr Kuldeep Srivastava said, "The main reason is stubble burning in Punjab and Haryana and local pollutants. Another reason is static winds which lead to pollutants accumulating." "It will stay so for the next 3-4 days," Dr Kuldeep added.