Delhi pollution drops into very poor category as Supreme Court limits festival fireworks

Air quality across Delhi has dropped into the "very poor" bracket ahead of the annual Diwali celebrations, prompting regional authorities to enforce emergency counter-pollution protocols.

On Wednesday morning, the capital recorded an Air Quality Index reading of 377, according to official monitoring figures. India's national pollution watchdog classifies any reading between 301 and 400 as very poor, while measurements above 400 represent severe conditions. Prolonged exposure to air at these levels poses serious health risks, particularly for elderly residents and young children, through microscopic PM2.5 particulates that penetrate deep into respiratory systems.

Officials have responded by activating Stage II of the Graded Response Action Plan, a regional framework that requires targeted efforts to control road dust, curb vehicle exhaust, and limit other primary emissions.

The decline in air cleanliness arrives shortly after an exceptionally mild October, which had seen Delhi record its lowest monthly average pollution levels in eight years following rain and gusty weather. However, shifting seasonal patterns have quickly reversed those gains. Calm winds, dropping temperatures, and smoke from agricultural stubble burning in nearby Punjab and Haryana have combined to trap pollutants over the metropolis.

The timing is especially sensitive because the city is preparing for Diwali, an event traditionally marked by large-scale firework displays that further saturate the atmosphere with fine particles and toxic fumes.

To manage the expected surge in smoke, India's Supreme Court issued instructions on Monday permitting only certified green firecrackers to be made, distributed, and used across the capital region during limited time windows on November 7 and 8. The permitted hours run from 06:00 to 07:00 and from 20:00 to 22:00 local time. The court also instituted a ban on setting off fireworks within 300 metres of sensitive locations, including medical centres and educational facilities.

Certified green pyrotechnics rely on alternative chemical mixtures intended to produce fewer emissions and are required to display verifiable QR codes. Even so, the court acknowledged that standard fireworks have regularly circulated under the guise of cleaner options during previous restrictions. Law enforcement personnel have been instructed to patrol retail zones, conduct random code inspections, and confiscate non-compliant items.

Severe smog around this period has previously forced local administrators to temporarily restrict vehicle usage, transition classes to hybrid schedules, and advise remote working.

Deteriorating air has also impacted other major urban centres in India. Mumbai, which usually benefits from coastal breezes, saw its reading hit 322 in late October amid dust, trash combustion, and low wind speeds, before clearing back to a satisfactory level of 89 by Wednesday.