Nat'l Institute of Environmental Health Sciences

In 2000, the National Institute of Environmental Health Sciences' National Toxicology Program published its 9th Report on Carcinogens, which included secondhand smoke on its list of known human carcinogens for the first time.

In 2002, the National Toxicology Program issued the updated 10th Report on Carcinogens, which reconfirms that secondhand smoke is a known human carcinogen, based on studies showing a causal relationship between secondhand smoke exposure and lung cancer, nasal sinus cancer, and other cancers.

In 2005, the National Toxicology Program issued its 11th Report on Carcinogens. The report contains a six-page section on tobacco and secondhand smoke, which again confirms the secondhand smoke is a known human carcinogen.