Adult health threats from secondhand smoke

Health experts have recognized the relationship between secondhand smoke and health risks for decades. Research exploring these connections is ongoing.

Some of the known or suspected health risks include:

Cancer:
In 1993, the Environmental Protection Agency placed environmental tobacco smoke in the most dangerous category of cancer-causing agents, and subsequent research has upheld that status.
Secondhand smoke is a known risk factor for lung cancer. Experts believe that secondhand smoke is to blame for roughly 3,000 deaths from lung cancer in adult nonsmokers each year in the United States. Secondhand smoke is also linked to cancer of the nasal sinuses. It's also been linked to cancers of the cervix, breast and bladder, but the evidence hasn't been as compelling as the link to lung cancer.

Heart disease:
Secondhand smoke harms the cardiovascular system of nonsmokers in many ways. For one thing, it causes coronary heart disease, such as a heart attack. It also damages blood vessels, interferes with circulation and increases the risk of blood clots. It's estimated that some 35,000 nonsmokers die of smoking-related heart disease in the United States every year.

Lung disease:
Chronic lung ailments, such as bronchitis and asthma, have been associated with secondhand smoke. Exposure to secondhand smoke is also associated with chest tightness at night and feelings of breathlessness after physical activity.