An article in Health about preventing lung cancer quoted Ticiana Leal, MD, assistant professor (CHS), Hematology, Medical Oncology and Palliative Care. 

The article focused on causes of lung cancer in people who do not smoke cigarettes. According to the American Lung Association, active smoking is responsible for an estimated 90 percent of lung cancer cases, but factors such as occupational exposure to carcinogens, outdoor air pollution, and radon exposure are involved in non-smoking-related lung cancers.   

Accordingly, suggestions of steps non-smokers can take include avoiding secondhand smoke, testing for radon in your home, ensuring work safety standards are met in high-risk industries, and eating a healthy diet that includes fruits and vegetables.

Resources:

• "7 Causes of Lung Cancer in Non-Smokers," Health.com, August 8, 2017