It is true that lung cancer is commonly seen among smokers. About 85 per cent of all lung cancers are directly related to tobacco use, especially smoking. However, nearly 10–20 per cent of lung cancers each year occur in people who have never smoked or who have smoked fewer than 100 cigarettes in their lifetime.It is also the fifth most common cause of cancer-related death worldwide. Even if you have never smoked in your life, there is a possibility that you may still get lung cancer. While smoking has traditionally been seen as the leading culprit, other risk factors are increasingly being recognised.Pollution, Family History and Hidden Risks“We have seen that there are many other factors which may lead to the development of lung cancers. The most important ones are air pollution, especially in Southeast Asia and the Indian subcontinent," says Dr Kamran Ali, Principal Consultant, Lung Transplant and Thoracic Surgery, Max Super Speciality Hospital, New Delhi. He explains that pollutants from vehicles and industry, such as benzene and heavy metals, can contribute to lung cancer risk.Long-term exposure to polluted air may cause persistent inflammation in the lungs, weakening the immune system and making it easier for cancer cells to grow. He warns about exposure to radon gas, which is found in soil and can sometimes creep into homes.Long-term exposure to second-hand smoking or third-hand smoking also increases risk, says Dr Ali, pointing out that many people underestimate these dangers. He adds that genetic susceptibility also plays a role: "If your parents have lung cancer or your sibling has lung cancer, it does increase the risk of lung cancer for you as well.”He also explains a lesser-known cancer, saying, “There is a separate intake entity called mesothelioma which arises from the surface of the lung. It is not from the lung itself. It is from the surface of it which is associated with asbestos.” Although asbestos is now banned, it was previously used in roofing and packaging industries. Dr Ali cautions against exposure to other heavy metals like chromium.How Non-Smoker Lung Cancer DiffersNon-smoker lung cancers are slightly different from smokers’ lung cancers. “Classically, non-smokers’ lung cancer is usually an adenocarcinoma, which is found in the outer third of the lung surface,” he explains, adding that it often presents more vaguely than smoking-related cancers: “It also presents as a vague or a diffuse involvement of the lung rather than like a nodule or a mass.”Dr Ali says it is typically slow-growing and less likely to spread to other parts of the body compared to lung cancer in smokers.Watch for the Silent SignsSo lung cancer is a silent killer. If you have symptoms like a cough that worsens over time or a cough that does not go away, blood while you cough, unexplained weight loss, shortness of breath, or chest pain, you need to consult your local thoracic surgeon. The expert stresses that early detection is critical for effective treatment.Prevention Starts with AwarenessTo lower your risk, Dr Ali shares these preventive measures:Refrain from venturing out of your house when the air pollution level is in a severe state outside.If necessary to go outside, use an N95 mask in polluted areas.You should use air purifiers indoors to filter out harmful particles.Incorporate fresh fruits and vegetables in your daily diet.Drink plenty of water to keep you hydrated.You can practise some appropriate breathing exercises to enhance your lung function.If you have a strong family history of lung cancer, you must meet a thoracic surgeon or oncologist to get yourself evaluated.