The Supreme Court on Monday issued notices to the Centre and the state governments of Uttar Pradesh, Punjab, Haryana and Delhi to curb air pollution. Observing that it was an emergency-like situation, the court sought immediate action from the governments.

The bench headed by Chief Justice Dipak Misra had admitted the petition for urgent hearing earlier in the day. The plea by lawyer RK Kapoor sought immediate action against stubble burning and construction dust around the city to control pollution.

A severe smog has enveloped Delhi and several other north Indian cities since November 7. The air quality deteriorated on Monday after marginally improving over the weekend. The Air Quality Index reading in several areas in Delhi was above 500. Central Delhi’s Lodhi Road (Air Quality Index of 567) and north-west Delhi’s Pitampura (Air Quality Index of 544) had the worstreadings at 2.30 pm.

An Air Quality Index reading of up to 50 is considered “good”, and up to 100 is considered “satisfactory”. A reading between 401-500 is ranked “severe” on the index, which means the air is dangerously filled with pollutants. Monday’s reading in Delhi far surpasses the categories on the Air Quality Index chart.

The pollution might worsen from November 15 after light rain is expected in the city. While the rain may help marginally dissipate smog, it will lead to a buildup of moisture in the air, which could further trap pollutants, the Hindustan Times reported.