Air quality in Delhi worsened on Saturday with PM 10 level at 267 and PM 2.5 level at 226 – both in “poor” category on the Air Quality Index, reported ANI.

The air quality in the national Capital may deteriorate over the next few days due to the burning of effigies on Dussehra, stubble burning and low wind speed, the Hindustan Times reported quoting a senior official of the Central Pollution Control Board.

According to the National Air Quality Index, Anand Vihar recorded an AQI of 381, IGI Airport recorded 305 and RK Puram recorded 352 at 10 am on Saturday – all in the “very poor” category. About 31 areas in Delhi recorded “very poor” air quality while two areas showed “severe” air quality levels, said the pollution control board, according to PTI.

System of Air Quality and Weather Forecasting And Research has forecast “very poor” air quality on Sunday and “poor” over the next week. On Saturday, the levels of PM2.5, which is presence of particles in the air with a diameter of less than 2.5 micrometres, touched a new high at 158. PM10 levels in Delhi stood at 270.

An AQI 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”.

“We are issuing directions for specific locations where pollution levels are high,” The Times of India quoted Sunita Narain, a member of the Environment Pollution Control Authority, as saying. “A meeting may be held next week if the levels reach close to severe.”

NASA satellite images from Friday showed high aerosol optical depth over the northern states and the Himalayan foothills over the past couple of days.

High aerosol optical depth are an indirect proxy for air quality since solid and liquid particles in polluted air block sunlight and lead to smog. Ashim K Mitra, a scientist from the satellite meteorology division of the India Meteorological Department, tweeted images showing the aerosol optical depth.

“Northern India and the foothills are affected by high aerosol levels,” said an unidentified Met department official. “Unless there are strong winds to drive these aerosols away, they will remain accumulated. During Diwali, the situation will obviously deteriorate further unless strict restrictions are placed on firecrackers.”

In September 2017, the Supreme Court suspended the sale of firecrackers in Delhi and NCR till November 1, 2017 after air quality dipped during Diwali the previous year. However, officials in the pollution control board said they have not restricted the use of firecrackers this year because they are awaiting a Supreme Court verdict on a petition calling for a nationwide ban on the sale and use of firecrackers during Diwali.