About 20 million people in New Delhi woke to the world's highest PM2.5 readings after Diwali, with levels over 40 times the WHO annual guideline, according to IQAir. The spike follows Diwali fireworks and seasonally worsens due to crop stubble burning in surrounding states. Residents reported burning eyes, sore throats and frustration at weak enforcement of rules, including a limited allowance for 'green' firecrackers. Past measures — from odd-even traffic rules to smog towers — have produced limited improvements amid coordination and enforcement challenges.
After Diwali, New Delhi Wakes to World's Most Polluted Air — PM2.5 Over 40× WHO Guideline
About 20 million people in New Delhi woke to the world's highest PM2.5 readings after Diwali, with levels over 40 times the WHO annual guideline, according to IQAir. The spike follows Diwali fireworks and seasonally worsens due to crop stubble burning in surrounding states. Residents reported burning eyes, sore throats and frustration at weak enforcement of rules, including a limited allowance for 'green' firecrackers. Past measures — from odd-even traffic rules to smog towers — have produced limited improvements amid coordination and enforcement challenges.
07:20 PM, 11/11/2025Environment
New Delhi wakes to hazardous pollution levels after Diwali
Around 20 million residents of India’s capital awoke on Wednesday to air pollution higher than any other major city in the world, a day after Diwali celebrations. Swiss air-quality tracker IQAir reported New Delhi’s PM2.5 concentration at more than 40 times the World Health Organization’s annual guideline.
PM2.5 refers to fine particulate matter small enough to penetrate deep into the lungs and enter the bloodstream, increasing the risk of respiratory and cardiovascular illness. Delhi experiences heavy pollution throughout the year, but conditions typically worsen in winter when farmers in surrounding states burn crop stubble to clear fields for the next planting season.
This week’s sharp deterioration followed widespread Diwali firecracker use. Fireworks and firecrackers emit sulfur and nitrogen oxides and can release harmful heavy metals, all of which contribute to dangerous short-term spikes in pollution.
“Year on year, it goes from bad to worse,” said Anushka Singh, 30, a graphic designer who stays home during Diwali to shield her dog from incessant noise. She described a scratchy throat and burning eyes when stepping outside the day after the festival.
Authorities imposed a complete ban in 2020 on manufacturing, selling and using firecrackers in New Delhi because of hazardous pollution. This year, the Supreme Court allowed limited use of so-called 'green' firecrackers—marketed as lower-emission alternatives—within a restricted time window. Residents reported the curfew was poorly enforced and that conventional, higher-polluting crackers remained available.
Chandra Tandon, 52, who runs a corner shop, acknowledged that bursting crackers is "part of the fun" but said the resulting air made it difficult for many to cope. “I was breathing in those fumes throughout and it’s definitely not good,” she said, urging more responsible behavior from adults so children can enjoy traditions more safely.
Past measures and ongoing challenges
Delhi’s officials have tried a variety of measures to curb pollution: sprinkling water on roads, an 'odd-even' traffic rule that restricts cars by license plate on alternate days, and two smog towers installed in 2018 that cost about 200 million rupees (approximately $2.4 million). Experts say these measures have had limited impact due to weak enforcement, a lack of coordinated regional action, and the scale of pollution sources.
At the same time, India faces the challenge of powering a rapidly growing economy and meeting the energy needs of a population of roughly 1.4 billion. On Wednesday, IQAir ranked three Indian cities among the world's most polluted: New Delhi, Kolkata (4th), and Mumbai (10th).
What to watch: Policymakers, courts and local authorities will likely need stronger enforcement, regional cooperation on crop residue management, and continued investment in cleaner energy and transport solutions to prevent recurring post-festival pollution spikes.