The Supreme Court on Monday directed the governments of Delhi and adjoining areas in the National Capital Region to continue implementing strict anti-pollution measures under Stage 4 of the Graded Response Action Plan, or GRAP, till further orders even if the air quality improves to settle below an index value of 450, reported The Hindu.

The court also rapped the Delhi government for delaying the implementation of stricter anti-air pollution measures under GRAP Stage 4. The GRAP is a set of incremental anti-pollution measures that are triggered to prevent the further worsening of air quality once it reaches a certain threshold in the National Capital Region.

This came on a day when the city’s air quality index touched 493, the highest this winter, reported India Today.

The Commission for Air Quality Management in the National Capital Region ordered the implementation of GRAP Stage 4 measures from Monday, barring the entry of trucks into the capital and temporarily halting the construction of public projects.

A bench of Justices Abhay S Oka and Augustine George Masih noted that there had been a delay in implementing the measures under Stage 4 despite alarming levels of air pollution in Delhi.

“The moment the AQI reaches between 300 and 400, Stage 4 has to be invoked,” the bench told the counsel. “How can you take risks in these matters by delaying the applicability of Stage 4 of GRAP?”

The bench also directed all governments in the National Capital Region to consider suspending in-person classes for school students up to Class 12.

The court has been dealing with a matter related to air pollution caused by stubble burning, firecrackers, vehicular emissions, garbage burning and industrial pollution. Orders have been issued concerning stubble burning and firecrackers, with the other sources set to be reviewed in the coming days.

On November 11, the court said that no religion promotes any activity that causes pollution. It criticised the Delhi government for its failure to enforce a ban on the use of firecrackers in the national capital during Diwali festivities.

The court had also directed the Commission for Air Quality Management to immediately decide on implementing Stage 4 restrictions, including reducing office capacity to 50% in the National Capital Region and allowing central government employees to work from home.

The bench criticised the Commission for waiting until November 14 to take action, despite the air quality index breaching the 400 mark on November 12.

The court criticised the pollution watchdog for assuming that air quality would improve instead of worsening.

Also read: What is GRAP, the National Capital Region’s plan to tackle air pollution?