According to some estimates, approximately 10%-15% of lung cancer cases occur in non-smokers. Since the cause of this disease is almost overwhelmingly related to tobacco use, the appearance of lung cancer in non-smokers remains somewhat of a mystery. Though few definitive answers exist, medical experts believe that exposure to certain chemicals, passive inhalation of tobacco, and genetics may play a part in the development of lung cancer in non-smokers.
Passive inhalation, also known as secondhand smoke, is considered a major culprit in cases of lung cancer in non-smokers. According to some experts, people who live with a smoker and have regular exposure to secondhand smoke are at a much higher risk of getting lung cancer than people who do not live with a smoker. Tobacco remains a destructive substance for lung tissue, even if not used directly. Despite what many experts believe is the very real risk factor of secondhand smoking, it is not always behind cases of lung cancer in non-smokers.
Radon gas is a serious contaminant that lurks in the soil and forms through the decay of uranium. Studies have shown that radon gas from the ground around a home or building can easily get into pipes, and vents and infiltrate the air of the house. Odorless and colorless, radon gas may be a silent risk factor for the development in lung cancer both in smokers and non-smokers. Considerable evidence shows that high exposure to this common gas increases the likelihood for all lung diseases, including both cancer and emphysema. Home supply stores carry simple kits that may be used to test for radon gas contamination, if this is a concern.
Radon is far from the only inhaled chemical that is linked to lung cancer in non-smokers. Asbestos, chromium, and tar inhalation have all been cited by medical professionals as possible causes of lung cancer. Industrial workers are frequently exposed to these and other chemicals on the job, especially if adequate safety equipment is not provided. Generally, since the damage is usually cumulative, the longer the exposure time, the more risk of developing lung diseases or related illnesses.
Studies have shown that there may be some kind of genetic predisposition toward contraction of lung cancer. Research suggests that people who have a close family member with lung cancer, such as a parent or sibling, are much more likely to develop the disease. Until further genetic research can be done, this link remains largely theoretical.