Lung cancer traditionally presents itself when associated with cigarette smoking, but now lung cancer is increasingly being diagnosed in people who have never smoked a day in their lives. This increases the concern of a silent but growing health crisis in our country. One that needs urgent awareness, prevention, and systematic change.

Rising incidence in non-smokers

According to the National Cancer Registry data, with over 72,000 new cases, approximately 66,000 deaths occur each year, as lung cancer remains one of the leading causes of cancer mortality in India. While smoking is a major cause, recent studies show that more than half of lung cancer patients diagnosed in certain centres were non-smokers. A study at a government hospital in north India found that 52% of lung cancer cases were among non-smokers. It gives a clear indication that other environmental and biological factors are at play.

A major concern has been raised that air pollution, especially fine particles, penetrates deep into our lung tissue, which leads to chronic inflammation and genetic damage over years of exposure. According to the World Health Organization, 3.2 million premature deaths have been linked to household air pollution. The rising number in lung health has been seen largely in women and children.

Certain subtypes of lung cancer, particularly adenocarcinoma, are now more common in non-smokers, mostly in women, including most non-smoker cases in the Indian population. A recent study in Europe found that women who regularly use cleaning products such as air fragrances, chemical cleaners, and household sprays have experienced a decline in their lung function, which is seen to be equivalent to smoking 10 to 20 cigarettes a day. To avoid this, opt for liquid-based wipes, as they do not release fewer airborne particles. Use organic and natural cleaners, such as baking soda, lemon, and vinegar.

Why non-smokers are at risk

Air pollution: Chronic exposure to outdoor pollutants, especially in urban cities with high AQI, increases lung cancer risk for healthy people. Crop burning in northern India significantly worsens air quality and adds to the burden of fine particulate pollution (PM2.5). Although it’s one part of a larger pollution problem, repeated exposure to this kind of pollution damages lungs and contributes to long-term risks such as chronic respiratory disease and cancer.

Indoor air pollution: In many rural and urban households, cooking with biomass fuels like wood, coal, or dung releases carcinogens that can damage lungs over time. Household cleaning products contain components such as ammonia, bleach, synthetic fragrances, and formaldehyde. These release volatile organic compounds and fine particles such as PM2.5 and PM10, which penetrate the lung.

Second-hand smoking: Non-smokers living among smokers or exposed in public areas have a measurably increased risk.

Exposure but occupational: When exposed to industrial toxins such as asbestos, heavy metals, and silica dust, the risk is equivalent to smoking.

Genetic susceptibility: Certain hereditary patterns and mutations make some individuals more vulnerable to cancerous changes.

Early symptoms

Early detection significantly improves outcomes in lung cancer. Unfortunately, non-smoker lung cancer often remains silent until advanced stages because early symptoms are subtle and easily dismissed. These include:

Persistent dry cough that lasts more than a few weeks.

Shortness of breath or difficulty in breathing.

Fatigue or weakness

Sudden weight loss

Chest pain or chest discomfort

What can be done

Even though not all cases of lung cancer are preventable, many can be significantly reduced.

Improving air quality and reducing emissions must be national priorities, especially in urban areas.

Using clean cooking fuels, good kitchen ventilation, and reduced biomass can lower the indoor risk.

Avoiding public areas to safeguard yourself from second-hand smoking; a ban on smoking in public spaces should also be implemented in more cities.

Initiating health education and awareness in public on early screenings can save lives.

By Dr Aishwarya Rajkumar, senior consultant - Pulmonology, Rela Hospital, Chennai.