Although smoking is a risk factor for developing lung cancer, it does not mean non-smokers are protected from the disease. Where globally, about 25% of lung cancer patients have never smoked, in Singapore almost 40% of lung cancer patients are never smokers. Lately, it has been found that the proportion of never-smokers with lung cancer has more than doubled from 13% to 28%.
Exposure to radon gas that is released when uranium in the soil breaks down naturally, second hand smoke, asbestos used in home insulation, auto manufacturing, shingles, ceiling tiles, flooring, and air pollution have all been known to cause lung cancer in non-smokers.
Exposure to chemicals like arsenic, chromium compounds, nickel compounds in occupations such as sandblasting, metalworking, printing, ceramic making, uranium mining and Glass manufacturing has also been known to cause lung cancer.
Genetic predisposition by having family history of lung cancer is also a factor responsible for lung cancer in the non-smokers. Lung cancer in non-smokers is often misdiagnosed initially as respiratory infection or even allergies, only to realise the correct diagnose after a significant delay.
What can you do? Do not ignore any respiratory symptom or an chest X-ray abnormality assuming that non-smokers do not get lung cancer.