The Supreme Court on Thursday permitted the Commission for Air Quality Management to relax the emergency measures under stage 4 of the Graded Response Action Plan to stage 2 in view of Delhi’s improving air quality index, Bar and Bench reported.

The Graded Response Action Plan, or GRAP, is a set of incremental anti-pollution measures that are triggered to prevent the worsening of air quality once it reaches a certain threshold in the National Capital Region.

Stage 4 of GRAP mandates a ban on trucks entering the region and halting construction activities for public and private projects. Stage 2 imposes a ban on the use of coal, firewood and diesel generators, except for emergency and essential services.

Advertisement

A bench of Justices Abhay S Oka and Augustine George Masih on Thursday also asked the air quality panel to consider introducing a few measures that are under GRAP stage 3, which includes a shutdown on all mining and stone crushing activities in the region, among other actions, Live Law reported.

The bench has been dealing with a matter related to air pollution caused by stubble burning, firecrackers, vehicular emissions, garbage burning and industrial pollution in Delhi and the surrounding areas.

On November 17, amid worsening pollution, the Commission for Air Quality Management ordered the implementation of stage 4 of GRAP across the National Capital Region. The court on Monday refused to relax measures under stage 4 till the air quality index showed a “downward trend”.

Advertisement

On Thursday, the average air quality index in Delhi stood at 165 at 5.30 pm, according to data from the Central Pollution Control Board

An index value between 0 and 50 indicates “Good” air quality, between 51 and 100 indicates “Satisfactory” air quality and between 101 and 200 indicates “Moderate” air quality.

As the index value increases, air quality deteriorates. A value of 201 and 300 means “Poor” air quality while between 301 and 400 indicates “Very Poor” air. Prolonged exposure to such air quality can lead to serious respiratory illnesses in otherwise healthy people.

Advertisement

Between 401 and 450 indicates “Severe” air pollution while anything above the 450 threshold is termed “Severe Plus”.

"We have perused the figures of AQI from November 18 to December 4,” the bench said on Thursday, according to Bar and Bench. “Up to November 30, it was consistently above 300 and it is only during last four days that the levels came down below 300.”

The court said that it would not be appropriate to allow the air quality panel to enforce measures below stage 2 of GRAP taking into account the data it had reviewed. It also noted that stage 3 would have to be implemented as a precautionary measure if the air quality index crossed 350.

Advertisement

“If AQI crosses 400 on a given day, stage 4 to be reintroduced,” it added.


Also read: Not stubble burning, cars are the main villain in Delhi's apocalyptic air pollution