Secondhand smoke, or passive smoking, has received a great deal of attention during the past decade for its association with medical conditions, including cancer. The U.S. Environmental Protection Agency (EPA) has classified secondhand smoke as a “known human carcinogen.” The smoke contains more than 60 chemical compounds that are known or suspected to cause cancer.

Each year in the United States, an estimated 3,400 nonsmokers will die of cancer, according to the American Cancer Society. Secondhand smoke is responsible for severla other respiratory problems, including emphysema, asthma and respiratory infections.

In 2006, the U.S. Surgeon General published a report about the dangers of secondhand smoke. The report concluded that secondhand smoke causes premature death in children and adults who do not smoke. Exposure to secondhand smoke can cause cardiovascular problems, in addition to lung cancer. It also indicated that there is some evidence that secondhand smoke may be linked to breast cancer. However, there was not sufficient proof of the connection.

The report concluded that there is no risk-free level of exposure to secondhand smoke. There are laws in all states that restrict smoking in certain public places. The restrictions vary from the simplest form – no smoking in government buildings – to more stringent ones, such as smoking bans in all indoor and outdoor public areas.