Every winter, a grey haze settles over many Indian cities, and most of us think of the usual consequences like a scratchy throat, watery eyes, or a cough that won’t go away. But doctors say the risk can go further than discomfort, because smog can make it easier for serious chest infections like pneumonia to take hold.
We spoke to two pulmonologists about how polluted air weakens the lungs, why winter makes it worse, who is most at risk, and the practical steps that can help you breathe easier through the season.
How smog makes lungs easier to infect
“Pneumonia is the infection and inflammation of lungs, often presenting as cough, fever, breathlessness and chest pain,” says Dr. Abdul Raouf Wani, Pulmonologist. “Microorganisms like bacteria, fungi and viruses cause the infection, but smog gives them an easier route into the lungs and a better chance of taking hold by weakening the lungs’ natural defences,” he explains.
Dr. Sunny Kalra, Unit Head - Pulmonology, Max Hospital Gurugram, makes the same point. “While air pollution does not directly trigger pneumonia, it impairs the natural defense capability of the lungs thereby making people susceptible to infections of both bacterial and viral nature,” he says.
What the particles do inside the lungs
“Our respiratory tract relies on a natural clearing system called the mucociliary escalator,” Dr. Wani says, adding that tiny hair-like cilia lining the bronchial tree constantly sweep inhaled germs, dust and mucus upward and out.
“Smog carries PM2.5 particles that impair the cilia, inflame the airway lining and settle deep in the air sacs,” he tells us.
“Macrophages, the immune cells that engulf inhaled germs, also suffer,” Dr. Wani says. Once they take in pollution particles, he says, they capture bacteria less effectively, so more germs survive and multiply.
Why winter makes it worse
“In winter, cold, still air traps smog near the ground, people keep windows shut and gather indoors, and influenza and other viruses spread more readily,” Dr. Wani says. “A viral infection in an irritated lung often progresses to pneumonia,” he cautions.
Who is most at risk
“Young children breathe faster and take in more polluted air for their size, while their lungs and immune systems are still developing,” Dr. Wani says. “Older adults have weaker immune defences and often an undiagnosed heart or lung condition. Pregnant women breathe more air, and pregnancy alters immunity. Smokers start with damaged airways,” he explains.
“Asthma and long-term lung disease keep the airways inflamed, and smog aggravates the inflammation further,” he says. “Diabetes blunts the body’s response to infection, and heart disease leaves less reserve to cope with pneumonia,” Dr. Wani adds.
When to get checked
According to Dr. Wani, a chest X-ray and an oxygen check with a pulse oximeter alongside physical examination by a clinician can help identify the infection early if someone has a cough lasting more than a week, or fever combined with breathlessness or chest pain.
How to protect your lungs this winter
“Check the AQI before going out and avoid morning walks on days of very poor air, since pollution is often highest in the early hours,” Dr. Wani advises. “Wear a snug-fitting N95 mask outdoors. Keep windows shut when pollution peaks and run a HEPA air purifier in the bedroom,” he says. “Maintain fluid intake with warm liquids, and eat protein-rich meals such as dal, eggs or paneer along with fresh fruit and vegetables,” he adds.
Dr. Kalra says it is also important “not to smoke, burn anything indoors, and maintain good ventilation if outdoor air quality allows it.” “Vaccination against influenza and pneumonia, which doctors recommend, can also prevent some illnesses,” he says.
Winter smog poses more than just an environmental problem; it is a significant respiratory health issue that requires precaution and prompt medical treatment.
