The Supreme Court-appointed Environmental Pollution (Prevention and Control) Authority on Monday banned construction work across Delhi and the National Capital Region, as well as industrial activity in heavily polluted areas till Wednesday, PTI reported.

The authority took the decision in view of the “severe” air quality in New Delhi. At 5 pm on Monday, the air quality index was at 447, according to Central Pollution Control Board data.

An Air Quality Index between 0 and 50 is considered “good”, 51 and 100 “satisfactory”, 101 and 200 “moderate”, 201 and 300 “poor”, 301 and 400 “very poor”, and 401 and 500 “severe”. The Central Pollution Control Board has advised Delhi residents to keep outdoor activities to a minimum for the next few days and avoid private vehicles.

EPCA Chairperson Bhure Lal told Delhi Chief Secretary Vijay Kumar Dev in a letter that industries located in Wazirpur, Mundka, Narela, Bawana, Sahibabad and Faridabad areas will remain shut till Wednesday. The authority also banned all construction work in Delhi, Faridabad, Gurugram, Ghaziabad and Noida till Wednesday.

The EPCA asked the Delhi Traffic Police to prevent congestion in high traffic corridors. It also asked the traffic police to ensure that heavy duty vehicles travel through the eastern and western peripheral expressways.

The EPCA also asked government agencies to take strict action against illegal industries, and activities like waste burning. “The ventilation index which allows dispersion of pollutants is extremely poor and it is expected that these conditions will prevail for the next two days,” Lal said in the letter to Dev.

The Indian Institute of Tropical Meteorology said that the ventilation index in Delhi was measured at 4,500 sqm/second on Monday, PTI reported. An index value below 6,000 is unfavourable for dispersion of pollutants.