The hazardous smog, worst in 17 years, which has kept Delhi shrouded since Diwali lingered on, as the overall air quality oscillated between 'severe' and 'very poor' categories.
A senior IMD official said the pollutants are barely dispersing due to calm wind movement and foggy conditions. The situation might improve in the next three-four days, he said.
The 24-hour-average (rolling) of PM 2.5 and PM 10 were 225 and 389 micrograms per cubic metre respectively as per SAFAR (System of Air Quality and Weather Forecasting And Research) at 6pm.
Six out of eight stations of SAFAR had air quality in the very poor category while two had an AQI of severe.
However, the peak levels of pollution continued to violate the safe limits by over 10 times, even in densely populated areas like RK Puram and border areas like Anand Vihar.
At 10.30am, RK Puram had PM 10 (coarse respirable particles) at over 1,000 micrograms per cubic metre, way above the 24-hour safe limit of 100.
At Anand Vihar, PM 2.5 (finer and deadlier) peaked at 522 micrograms per cubic metre at 7.30 AM, as against its prescribed standard of 60 micrograms per cubic metre.
"As per the model sensitivity simulations, it is predicted that even if winds becomes 3km/hr, pollution could go down to Very Poor in a daytime provided winds remain North-Easterly," SAFAR had said.
Green body CSE had said on Thursday that according to the Indian Meteorological Department, the city is experiencing the the worst smog with very poor visibility in the last 17 years.
Prolonged exposure to severe category air may affect healthy people and seriously impact those with existing diseases while very poor category may cause respiratory illness.
Children, elderly and the sick are considered most vulnerable to the harmful effects of hazardous air.
Government blames crop burning in Punjab, Haryana
The Delhi government's inter-ministerial task force headed by PWD minister Satyendar Jain to combat the pollution menace identified crop burning in Punjab and Haryana as one of the major factors behind the spiralling level of pollutants.
State environment minister Imran Hussain wrote to his Union counterpart Anil Madhav Dave requesting strict action against crop burning in the neighbouring states.