What happens to your lungs after one year in a highly polluted city like Delhi

The Hindu

a day ago

If you've been living in Delhi for a year or more, chances are your lungs have already started to feel the impact, even if you're otherwise healthy.
Delhi's air quality, especiallyduring the winter months, routinely crosses alarmingly high pollution levels. PM2.5, fine particulate matter known to infiltrate deep into the lungs, often climbs beyond 255 μg/m³, occasionally touching 400–500 μg/m³ during smog episodes. For context, India's own safe limit, under the National Ambient Air Quality Standards (NAAQS), is 40 μg/m³.
So what does this mean for your lungs after one year in the capital?
The data on Delhi air
Several health studies suggest a worrying trend. A recent comparative analysis showed that 40.3% of Delhi residents have reduced lung function — double the rate observed in areas with significantly cleaner air. One particularly striking figure: 2.2 million children in Delhi are already showing signs of lung damage. Nearly one in three children suffers from some form of respiratory difficulty.
Adults aren't spared either. Even those without pre-existing conditions report more frequent respiratory infections, shortness of breath, and a lingering cough that simply doesn't go away. In fact, the likelihood of developing chronic respiratory symptoms in Delhi is 1.7 times higher than in places like Pauri Garhwal, a region with far cleaner air.
Pollution alters your lungs
In the first few months of exposure, symptoms might be mild — a sore throat, an occasional wheeze, or a nagging cold. But over time, the lungs adapt in ways that aren't healthy. Medical specialists warn that by the 4–8 month mark, the lungs are in a state of chronic inflammation. They're working harder to filter the air, leading to cellular changes that can impair function.
By the end of a full year, long-term exposure sets in. Lung capacity decreases, particularly in children and older adults. For those with asthma or COPD (chronic obstructive pulmonary disease), this can mean more frequent flare-ups and hospital visits. Some research even indicates that exposure to these levels of air pollution can reduce overall lung growth in children — an effect that may be irreversible.
Air pollution and cancer
While most people associate Delhi's air with coughing and wheezing, there's a darker and more permanent consequence — cancer. According to the World Health Organization and the IARC (International Agency for Research on Cancer), air pollution is now classified as a Group 1 carcinogen — in the same category as tobacco.
Prolonged exposure to PM2.5 and other pollutants has been directly linked to an increased risk of lung cancer, especially in non-smokers. In fact, studies suggest that in heavily polluted urban environments, non-smokers can face nearly the same risk of developing lung cancer as light smokers.
Emerging research has also found possible associations between air pollution and other cancers, including bladder, breast, and even childhood leukaemia, although more data is needed on the subject. Delhi's rising cancer incidence, particularly lung cancer in non-smoking individuals, mirrors global patterns seen in cities with poor air quality.
Who is most at risk?
While everyone breathes the same air, certain groups are more vulnerable. These include: children, whose lungs are still developing; elderly individuals, often with pre-existing heart or lung conditions; pregnant women, due to potential impacts on foetal development; asthmatics and COPD patients, who experience more severe reactions and urban non-smokers, now facing rising lung cancer rates due to prolonged pollutant exposure.
What you can do
Moving out of Delhi is not an option for many. There are however, some practical measures you can take to protect your lungs. These include: staying indoors on high pollution days, especially early mornings and evenings; using air purifiers at home, preferably with HEPA filters; wearing N95/N99 masks when going outside — surgical masks simply don't offer enough protection; monitoring your health by perhaps considering an annual lung function test, especially if symptoms persist; eating smart with a diet rich in antioxidants — think fruits, vegetables, and nuts — that may help reduce inflammation caused by pollutants and avoiding smoking or passive smoke as when combined with air pollution, the cancer risk multiplies.
The bigger picture
Air pollution contributes to an estimated 1.5 million premature deaths in India each year, including deaths due to respiratory and cardiovascular diseases, strokes — and increasingly, cancer.
Delhi's authorities have introduced the Graded Response Action Plan (GRAP) and are promoting electric vehicles and cleaner fuel standards. While these are steps in the right direction, change will be slow. In the meantime, protecting your health is a personal responsibility.
If you've spent a year in Delhi and notice changes in your breathing, stamina, or general health, don't dismiss these symptoms as 'just the weather.' They may be early signs of something bigger.
Consult a healthcare provider, especially if you have a persistent cough, chest discomfort, or unexplained fatigue. Stay informed about the air quality index (AQI). Make your home a clean-air zone. And above all, don't ignore what your body is trying to tell you: your lungs may not get a second chance.
(Dr. Raajit Chanana, Senior Consultant, Dharamshila Narayana Hospital, Delhi. [e-mail])