For decades, lung cancer was widely linked with tobacco use. That perception is now changing as doctors report a growing number of cases among women who have never smoked. Medical experts say the trend highlights the need to look beyond cigarettes and examine other long term environmental exposures that may contribute to the disease.
Why More Nonsmoking Women Are Developing Lung Cancer
A recent case from Bengaluru reflects this concern. A 50 year old woman sought treatment after experiencing a persistent cough and occasional breathing difficulty for several weeks. She was initially treated for asthma, but her symptoms did not improve. A chest X ray later revealed fluid around her lungs, and further investigations confirmed advanced lung cancer that had already spread beyond the lungs.
Health experts say such cases are becoming increasingly common. According to Globocan estimates, India recorded 112659 new lung cancer cases in 2025, while 98687 people died from the disease. Although lung cancer ranks third in terms of total cancer cases in the country, it has become the leading cause of cancer related deaths.
The number of women affected has also increased significantly. Around two decades ago, women accounted for about 20 percent of lung cancer cases. That figure has now risen to nearly 30 percent, with more than 33600 women diagnosed in a single year.
Doctors also point to another striking trend. Studies indicate that between 60 percent and 85 percent of Indian women diagnosed with lung cancer have never smoked. Hospital based research has similarly found that between 15 percent and 35 percent of all lung cancer patients have no history of smoking, suggesting that several other risk factors may be involved.
Kitchen Smoke and Indoor Air Pollution Draw Attention:
Medical researchers believe lung cancer among nonsmokers cannot be explained by a single cause. Outdoor air pollution, exposure to secondhand smoke, workplace chemicals, radon gas, and genetic factors are all considered possible contributors.
Another area receiving increasing scientific attention is exposure to cooking fumes. When cooking oil is heated until it produces smoke, extremely fine particles and harmful chemicals are released into the air. These include substances such as formaldehyde, acrolein, and polycyclic aromatic hydrocarbons, which research suggests can damage lung tissue and may be associated with a higher cancer risk under certain conditions.
Research conducted over the past two decades has repeatedly shown that people who spend years cooking in poorly ventilated kitchens, especially those regularly exposed to cooking oil fumes, may face a greater risk of developing lung cancer. Some studies have found that long term exposure to cooking oil smoke is associated with an increase in lung cancer risk of up to 87 percent.
The association appears to be stronger among women who have never smoked. However, scientists stress that existing research does not conclude that cooking itself causes lung cancer. Instead, the concern lies in prolonged exposure to smoke in enclosed kitchens, repeatedly heating oil until it smokes, using solid fuels such as firewood or coal, and breathing polluted indoor air over many years.
The World Health Organization estimates that about 2.1 billion people around the world still rely on solid fuels including wood, coal, charcoal, and agricultural waste for daily cooking. Smoke generated from these fuels is known to increase the risk of respiratory diseases and may also contribute to lung cancer. Since women often spend more time cooking, they are more likely to experience prolonged exposure.
Doctors also warn that lung cancer can be difficult to detect in its early stages because its symptoms often resemble common respiratory illnesses. Persistent cough, breathing difficulty, repeated chest infections, unexplained weight loss, or symptoms mistaken for asthma, allergies, or tuberculosis can delay diagnosis until the disease has advanced.
Health experts recommend improving kitchen ventilation by using exhaust fans, keeping windows open while cooking, avoiding overheating cooking oil until it smokes, and choosing cooking methods such as steaming or boiling whenever possible. They say these simple measures can help reduce exposure to harmful indoor pollutants and support better long term lung health.