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.
"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.
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.
