While cigarette smoking is an undisputed cause of lung cancer, not all cases of lung cancer occur in smokers or former smokers. Gani Fawehinmi, who is reportedly a non-smoker, died of lung cancer on September 5, 2009. Although not every non-smoker suffering from lung cancer will have an identifiable risk factor for development of the disease, a number of conditions and circumstances have been identified that will increase a non-smoker’s chance of developing lung cancer.
Passive smoking, or the inhalation of tobacco smoke from other smokers sharing living or working quarters, is an established risk factor for the development of lung cancer. Non-smokers who reside with a smoker have a 24% increase in risk for developing lung cancer when compared with other non-smokers.
Radon gas, a naturally-occurring gas that forms when uranium decays, is another known cause of lung cancer. Radon gas can travel up through soil and enter homes through gaps in the foundation, pipes, drains, or other openings.
Asbestos is a compound that was widely used in the past as both thermal and acoustic insulation material. Microscopic fibers of asbestos break loose from the insulation material and are released into the air where they can be inhaled into the lungs. Asbestos fibers can persist for a lifetime in lung tissue following exposure to asbestos. Both lung cancer and a type of cancer known as mesothelioma are associated with exposure to asbestos.
Air pollution from vehicles, industry, and power plants, can raise the likelihood of developing lung cancer in exposed individuals. It has been estimated that up to 2,000 lung cancer deaths per year may be attributable to breathing polluted air, and many experts believe that prolonged exposure to highly polluted air can carry a risk for the development of lung cancer similar to that of passive smoking.