Nearly 20 million residents of India’s capital woke up on Wednesday to some of the worst air on the planet, just a day after Diwali festivities filled New Delhi’s skies with smoke from fireworks and firecrackers.

According to IQAir, a Swiss-based air quality monitoring firm, the city’s PM2.5 levels were more than 40 times higher than the World Health Organization’s recommended annual limit.

Delhi struggles with pollution throughout the year, but winter is especially hazardous. At this time of year, thousands of farmers in neighboring states burn leftover crop stubble, adding massive amounts of smoke to the already stagnant air.

The latest decline in air quality followed Diwali celebrations, during which firecrackers—known for releasing toxic sulfur oxides, nitrogen oxides, and harmful heavy metals—were widely used despite restrictions.

Authorities banned the production, sale, and use of firecrackers in 2020, but this year the Supreme Court allowed “green” firecrackers during a limited time window. Residents, however, reported that the rules were largely ignored, with firecrackers exploding well past the permitted hours, and many illegal varieties still circulating.

“Every year it just feels worse,” said 30-year-old Anushka Singh, who prefers to stay home with her dog during Diwali due to the constant noise. She added that the day after the festival, her throat burns and her eyes sting the moment she steps outside.

Store owner Chandra Tandon echoed similar concerns, saying that while firecrackers add excitement to the holiday, the aftermath is tough to endure. “I was breathing in those fumes all night. It’s definitely harmful,” she said. “Adults should at least take responsibility and reduce the damage.”

A Deepening Crisis

Despite years of political attention, Delhi’s air pollution crisis remains largely unresolved. Past measures—such as spraying water to settle dust, alternating vehicle travel based on license plate numbers, and building expensive smog towers—have delivered limited improvements due to weak enforcement.

At the same time, India continues to rapidly expand its economy and must meet the energy demands of more than 1.4 billion people, complicating efforts to curb pollution.

On Wednesday, IQAir ranked three Indian cities among the world’s most polluted:
• New Delhi topped the list
• Kolkata ranked fourth
• Mumbai placed tent