Other risk factors include:
Exposure to second hand smoke. People who don’t smoke but who breathe in the smoke of others may also be at a higher risk for lung cancer. Non-smoking spouses who live with a smoker, for example, have about a 20% to 30% greater risk of developing lung cancer than do spouses of non-smokers. Non-smokers exposed to tobacco smoke in the workplace are also more likely to get lung cancer.
Exposure to other environmental (things outside of the body) substances that can cause lung cancer include:
Brothers, sisters, and children of people who have had lung cancer may have a slightly higher risk themselves.
Among men, lung cancer rates are higher among white and black men, compared to men who are Asian, Pacific Islander or Hispanic. Non-Hispanic white women have higher lung cancer rates than other racial or ethnic groups. Again, this reflects the smoking patterns of these groups.
Smoking is by far the leading risk factor for lung cancer. Tobacco smoke causes nearly 9 out of 10 cases of lung cancer. The longer a person has been smoking and the more packs per day smoked, the greater the risk. If a person stops smoking before lung cancer develops, the lung tissue slowly returns to normal. Stopping smoking at any age lowers the risk of lung cancer.