Can Secondhand Smoke Increase the Risk of Cancer?
Yes! Secondhand smoke has been linked to lung cancer, nasal sinus cancer, and breast cancer. Cancer-causing chemicals may increase lifetime risk of cancer when exposure occurs during childhood, more so than in adulthood. About 3000 people die each year in the U.S. from lung cancer caused by secondhand smoke.
Breast cancer is a major cause of disease and death in women. Although a family history of breast cancer has been identified as a risk factor for breast cancer, the causes of the disease are not completely understood.
However, recent studies have found that secondhand smoke is one cause of breast cancer in younger women, before the age of menopause (below age 50). Related studies have shown that the breast may be especially sensitive to toxic chemicals during times of development and change, such as puberty. Therefore, it is particularly important for young women to avoid exposure to secondhand smoke when their breasts are developing, since chemicals in the smoke may cause changes that ultimately result in breast cancer.
Breast cancer is less common in young women than in older women, so only a small portion of breast cancer may result from secondhand smoke. Still, women (especially girls going through puberty) should avoid exposure to secondhand smoke since it remains one of the few preventable causes of breast cancer.