Even though lung cancer is most commonly seen in smokers, there are a handful of other environmental factors that can cause the disease. The leading cause of lung cancer in non-smokers is exposure to radon gas, according to the U.S. Environmental Protection Agency. It accounts for about 21,000 deaths from lung cancer each year. But because radon can’t be seen or smelled, the only way to know whether it’s accumulating in your home is to test for it.
Another big cause of lung cancer in non-smokers is simply breathing in secondhand smoke. That amounts to around 7,000 deaths from lung cancer each year. Exposure to other harmful chemicals like asbestos may also cause lung cancer. Asbestos was commonly used for insulation, roofing, and in various paints and plastics before it was banned by the EPA in 1989.
You may also be at a higher risk of developing lung cancer if you are constantly exposed to air pollution, or if you have a family history of lung cancer. New research also suggests that people infected with HIV have a higher risk of developing lung cancer compared to the general population. HIV weakens the immune system and reduces the body’s ability to fight off other viral infections that may cause various cancers.