New Delhi: With the thick blanket of smog engulfing the national capital, the Central Pollution Control Board Wednesday said rains and high speed wind can clear the pollutants in the air and increase visibility.
The meteorological department has already predicted rains over the couple of days.
The reason behind the thick smog, the CPCB said, is due to the reduction in the mixing height for the dispersion of pollutants due to lowering of the temperature.
"The mixing height for dispersion of pollutants has reduced due to the drop in temperature. A good rain is the need of the hour as that will wash out the pollutants or high speed wind will also clear the sky," said senior environment engineer Gurnam Singh.
He said the mean value of mixing height was 540 metres on the day of Diwali on November 3. On Monday, it reduced to 490 m and yesterday it was 408 m.
"Which means the pollutants have come down to the lower layer of the atmosphere and are causing this smog. Moreover, prevailing calm conditions (no wind) is not letting the pollutants to pass over," Singh said.
The mixing height on Sunday was 197 m between 6 PM and 6 AM, 178 m on Monday and 164 m yesterday, he said.
The lowering of the temperature along with vehicular pollution has added up to the smog.
Environment Pollution (Prevention and Control) Authority had recently held a meeting with Pollution Control Board chairman and state level senior officers of Haryana, Uttar Pradesh, Punjab and Delhi to deliberate on action points to be taken during the winter to curb pollution.
EPPCA has entrusted the Delhi Pollution Control Committee to keep close vigil on grounds and ensure that all generators installed in industrial and commercial establishments comply with the applicable emission and noise norms, and depute officials where public can inform complaints.
"We have also instructed DPCC to carry out frequent surprise visits of industrial areas and take action against the industries whose chimneys are found emitting dark smoke.
"Municipal authorities in association with DPCC have been asked to keep a check on leaf and garbage burning and take action against defaulters and transport departments of Delhi, to form teams for checking visibly polluting vehicles on roads at borders, especially diesel vehicles and vehicles entering Delhi," Bhure Lal, chairman of EPPCA, said.
Apart from that DPCC has been asked to ensure that proper dust control measures are taken at major construction sites.
"We have also asked the traffic police to ensure smooth flow of traffic and jams and slow moving traffic cause lot of pollution," Lal said.
Same instructions have been issued to the Haryana, Uttar Pradesh and Punjab.
"We have specifically asked the authorities to keep a watch on paddy straw burning which is illegal according to the Air Act. Smoke particles billowing from paddy straw burning move towards Delhi and add to the pollution," he said.
Last year, the capital witnessed a 12-day-long smog spell from October 26 to November 8.