Can secondhand marijuana smoke affect nonsmokers, including children?

Secondhand marihuana smoke contains tetrahydrocannabinol (THC), the chemical responsible for most of marihuana’s psychological effects, and many of the same toxic chemicals in smoked tobacco. Smoked marihuana has many of the same cancer-causing substances as smoked tobacco, but there are still a lot of unanswered questions around secondhand marihuana smoke exposure and its impact on chronic diseases such as heart disease, cancer, and lung diseases.