The National Green Tribunal on Wednesday extended the ban on the sale and use of all kinds of firecrackers in the Delhi-National Capital Region and in cities and towns where the air quality is “poor” during the coronavirus pandemic, ANI reported.

Earlier, a similar ban was imposed for the period between November 10 and November 30.

A bench headed by tribunal chairperson Adarsh Kumar Goel, however, allowed the use of green crackers from 11.55 pm to 12.30 am, on Christmas and New Year, at places where air quality is “moderate” or better.

An air quality index reading between 0 and 50 puts the air quality in “good” category. A reading between 51 and 100 puts it in the “satisfactory” category, between 101 and 200 in the “moderate” category, and between 201 and 300 in the “poor category”. The air quality is said to be “very poor” when the index value falls between 300 and 400. An index value between 400 and 500 puts the quality in the “severe” category.

It directed all district magistrates to ensure that banned firecrackers are not sold and asked them to recover compensation from violators.

Delhi’s air pollution typically worsens in October and November due to farmers burning stubble in neighbouring states, unfavourable wind speed and local emission of traffic fumes in the city. Firecrackers over Diwali and festival season add to the problem.

Pollution in the city had almost disappeared earlier this year, when the Centre imposed a countrywide lockdown to contain the coronavirus but has returned since the government began lifting restrictions at the end of August.