This small city has the world’s worst air

Dust from broken roads and nearby construction adds to Loni's poor air quality. (Deepak Rao/CNN via CNN Newsource)

LONI, India — The city of Loni is less than one hours’ drive from Delhi, but this rapidly growing industrial base beats the Indian capital when it comes to one unenviable title.

Last year, according to Swiss company IQAir, it had the world’s worst air quality.

Here, fumes from factories, exhaust from traffic and dust from construction produce a toxic mix that makes breathing an act of endurance for its 700,000 residents.

“Forget coughing, even breathing is difficult here,” said Manoj Kumar, 45, an e-rickshaw driver, who has lived in Loni his whole life.

Resident Mohammad Mohmin Khan said the pollution is so inescapable that he wears a mask every time he steps onto the city’s poorly paved roads.

“It’s here 24 hours a day,” he said. “No matter where you go.”

To determine the list of most polluted cities, IQ Air looked at fine particulate matter, or PM2.5, one of the smallest but most dangerous pollutants.

Last year, Loni’s average PM2.5 concentration was 112.5, according to IQ Air – 22 times the World Health Organization’s safe limit.

When inhaled, PM2.5 particulates travel deep into lung tissue where it can enter the bloodstream, and has been linked to asthma, heart and lung disease, cancer, and other respiratory illnesses, as well as cognitive impairment in children.

Dr. Anil Singh, who runs a clinic in Loni, said the number of patients he has seen with respiratory issues has increased in the last five years.

“I have particularly seen kids coming at a very young age with the symptoms of early asthma,” he said. “I can clearly say exposure to the environment is one of the prominent factors.”

World’s most polluted cities, 2025

• Loni, India
• Hotan, China
• Byrnihat, India
• Delhi, India
• Faisalbad, Pakistan
• Rahim Yar Khan, Pakistan
• Ghaziabad, India
• Lahore, Pakistan
• Sukkur, Pakistan
• Ula, India

Source: IQ Air World Air Quality Report 2025

Increased sickness

Three of the world’s top five most polluted cities last year were in India, according to IQ Air, with New Delhi once again emerging as the world’s most polluted capital.

Vehicle and industrial emissions, crop residue burning, and construction dust are the main sources of pollution in the country of 1.4 billion people, according to IQ Air.

From December to January, Loni and other cities across northern India routinely grapple with a severe spike in pollution during the cold, dry winter months.

Hazardous air gets trapped near the ground due to a phenomenon called temperature inversion, where a layer of cold, dense air acts like a lid and prevents pollution from rising.

Last April, a severe dust storm that swept through Delhi added more pollutants to Loni’s air, making it even more toxic, especially for its oldest and youngest residents.

Loni mother Khushi Feroze said her three-year-old son often gets allergies, coughs and stomach infections because of the pollution.

“We have to dust our home two to three times a day because so much dust comes in,” she said. “You can even see dust in the furthest room inside the house.”

Persistent pollution

India launched its Clean Air Program in 2019, ushering in strategies across 24 states and union territories to reduce particulate matter concentration by 40% by 2025-26.

The measures include cracking down on coal-based power plants, setting up air monitoring systems, and banning the burning of biomass.

Some Indian cities have seen improvements in their air quality, according to government data. Yet, experts suggest a lack of strict enforcement and coordination means progress has been slow.

Last October, the local government in Delhi attempted a cloud-seeding experiment to clean the capital’s air, but it was unsuccessful.

When the capital territory’s PM2.5 daily average concentration climbed to hazardous levels the following month, hundreds took part in a rare protest to call for stricter government action.

The struggle to clean India’s air stands in contrast to neighbouring China, where a multi-billion dollar and years-long effort to crack down on the country’s notoriously polluted skies has led to a reduction in national PM2.5 levels, according to the IQ Air report.

Elsewhere in the region, cities in Pakistan experienced some of the highest annual average PM2.5 concentrations globally, IQ Air said. The South Asian nation ranked the world’s most polluted country in 2025, according to the report.

Back in Loni, residents say they just want to breathe freely.

“Nothing has changed over the last 40 years,” Kumar, the e-rickshaw driver said.

For some, the only real solution might be to pack up and leave.

“We definitely feel much better when we leave here,” said Feroze. “There’s a lot of freshness wherever you go away from here. We don’t feel good here.”

By Esha Mitra, Trista Kurniawan and Deepak Rao, CNN