Top pulmonologist warns Delhi residents to leave as toxic air turns deadly

As a dense, choking haze smothered Delhi-NCR this week, one of India’s leading pulmonologists has sounded a grim warning: if you can afford to, get out of the city — at least for a few weeks.

“Everybody cannot afford to leave Delhi, but those who have the opportunity and ability should,” said Dr. Gopi Chand Khilnani, chairman of the PSRI Institute of Pulmonary, Critical Care and Sleep Medicine. “People with chronic lung or heart disease, or those on oxygen, must move to cleaner locations for six to eight weeks to avoid distress and hospitalization.”

On October 30, Delhi’s average Air Quality Index (AQI) hovered in the “very poor” range — one of the worst days of the year so far. Hospitals across the city have reported a surge in patients struggling to breathe, coughing incessantly, and battling aggravated asthma or chronic obstructive pulmonary disease (COPD).

‘I’ve never advised my children to live in Delhi-NCR’

Dr. Khilnani, who has spent over four decades in Delhi — including three decades at AIIMS — admits that while his professional life anchored him to the capital, he has never recommended the same for his family.

“My children and grandchildren have the choice to relocate, and I have never advised them to come to Delhi-NCR,” he said. “The first study we did on air pollution was in 1997. We knew then that this was dangerous — today it’s catastrophic.”

A silent killer shortening lives

Citing a University of Chicago study (AQLI 2023), Dr. Khilnani said the average life expectancy of Delhiites has been slashed by nearly 12 years due to prolonged exposure to toxic air — a figure that mirrors the health cost of living in a gas chamber.

The same study estimated that residents of nearby NCR cities — Noida, Gurugram, Faridabad, and Ghaziabad — also lose between 10 and 11 years of life expectancy to air pollution.

Air pollution, he warned, doesn’t just scar the lungs. It seeps into nearly every organ system — damaging the heart, kidneys, brain, endocrine system, and even weakening immunity. “We’re seeing rising cases of heart attacks, hypertension, diabetes, and even autoimmune diseases becoming more severe,” he said.

From cough to cancer — the deep toll of Delhi’s air

The veteran pulmonologist explained that fine particulate matter (PM2.5) — particles 30 times thinner than a human hair — penetrates deep into the lungs, impairing gas exchange and triggering inflammation. Even more dangerous are nanoparticles smaller than 0.1 microns, which can enter the bloodstream and travel to the heart and brain.

“Forty years ago, 90% of COPD cases were due to smoking. Today, half of them are caused by air pollution,” he said. “Similarly, 40% of lung cancers are now seen in people who have never smoked.”

The long-term exposure, he added, reduces lung capacity and immunity. “In just the last five days, many patients who were stable on medication have deteriorated. Several now require oxygen, and some have been shifted to the ICU.”

Purifiers help — but only in sealed rooms

While air purifiers can help reduce indoor exposure, Dr. Khilnani cautioned that their effectiveness is limited. “For an air purifier to work, it must run constantly and the room must remain shut. If doors are opened frequently, it’s useless,” he said.

He noted that the World Health Organization does not officially recognize air purifiers as a health intervention — yet for the elderly and those with chronic lung or heart diseases, they offer some relief indoors.