What evidence is there about the link between second-hand marijuana smoke and cancer?
In June 2002, a panel of experts brought together by the International Agency for Research on Cancer (an agency of the World Health Organization) determined that second-hand smoke causes cancer. And we know that marijuana and cigarette smoke contain as many as 50 of the same cancer causing substances. For these reasons, experts believe that exposure to second-hand marijuana smoke is at least as harmful as second-hand tobacco smoke.
