The air quality recorded in seven areas -- Anand Vihar, Ashok Vihar, Mundka, Nehru Nagar, Rohini, Vivek Vihar and Wazirpur -- fell in the 'severe' category. It was 'very poor' in 21 areas and 'poor' in three areas, the CPCB said.
The overall PM2.5 (fine particulate matter in the air with a diameter of less than 2.5 micrometre) level was recorded at 179 and the PM10 level at 333, it said.
In NCR, Ghaziabad recorded the worst air quality, in the 'severe' category at an AQI of 409. Faridabad and Noida recorded 'very poor' air quality, the CPCB said.
"The overall air quality over Delhi continues to remain 'very poor'. It will remain in 'very poor' category with small fluctuations in the next three days. Meteorological conditions are improving but not yet fully favourable," SAFAR said.
Calling open dumping of waste a major cause of air pollution affecting human health, CPCB Chairperson S P Parihar said during inspection of Shahdara drain between November 1 and 5, it was found that industrial solid waste was burnt and dumped at several stretches along the drain.
"Three incidents of waste burning were cited during November 4-5. Local residents have also reported several cases of waste burning along the drain which has caused air pollution," Parihar said in the notice dated December 3.
The Supreme Court had last week asked the CPCB to prosecute government officials for not acting on around 250 complaints received by it from citizens.
Delhi has been battling alarming levels of pollution for over a month with the air quality oscillating between 'poor' and 'severe' categories, which has prompted authorities to adopt a slew of measures.