New Delhi: The meteorological department has cautioned that pollution level during Diwali night is expected to be "severe" due to bursting of firecrackers and advised those persons with heart and lung diseases to stay indoors.
According to System of Air Quality, Weather Forecasting and Research (SAFAR), an agency of Ministry of Earth Science responsible to track pollution levels in the national capital said, November 12-13 is expected to witness dense haze formation.
The Diwali this year is falling on November 11.
The peak time pollution is expected at 1 am and the duration for maximum pollution will be between 10 pm to 2 pm on the intervening night of November 11 and 12 and 7-9 am early morning.
"Winter is now set and temperature during Diwali-2015 is going to be colder as compared to last year's Diwali-2014 which was in October. There is enough moisture in the air and atmospheric holding capacity is quite high for particles emitting from firecrackers. In all likelihood, air quality during Diwali-2015 is going to be inferior to that of Diwali-2014 owing to cooler temperature and downward shift of inversion layer," SAFAR's Project In-charge, Gurfan Beig, said.
There could be an increase in humidity level to above 96 per cent because of the cold weather.
"Under this condition, particles emitting from firework will sit on water droplets and multiply it resulting in more particles in suspended air itself. This process is called secondary particle formation which is likely to happen on November 12 and 13, making condition congenial for dense haze formation," Mr Beig said.
The PM (particulate matter) 2.5 level is expected to by 148 per cent on November 12 and 170 per cent in case of PM 10.
Noida, Delhi University (North) will record high level of pollution and Lodi Road, Mathura Road will witness less pollution.
"Everyone with heart and lung diseases, older and adult and children should should avoid all physical activity outdoors. There is a serious risk respiratory effects in general public in prolonged exposure," Mr Beig added.