Is secondhand smoke as dangerous as people say it is?

Second hand smoke: Yes. The U.S. Environmental protection agency, the U.S. National toxicology program, the U.S. Surgeon general, and the international agency for research on cancer have all classified secondhand smoke as a known human carcinogen (a cancer-causing agent).

Risks less but there: While the odds are less, secondhand smoke has been linked to the development of emphysema and heart disease, just like smoking. So not as intensely risky as smoking, but still risky. People who live with smokers do need to be careful and mind their own health.