When people hear “lung cancer”, they often associate the disease with smoking. While tobacco use remains one of the biggest risk factors for lung cancer, the disease can also affect people who have never smoked. In fact, several environmental, genetic and occupational factors can increase the risk of lung cancer among non-smokers. Why are non-smokers developing lung cancerAccording to Dr Eshpuniyani, non-smokers can still be exposed to several risk factors that may increase their vulnerability to lung cancer. Genetics: A family history of lung cancer can also make an individual more susceptible to the disease.