A possible chemical basis for the higher mutagenicity of marijuana smoke as compared to tobacco smoke.

The results of comparative anslyses of polynuclear aromatic hydrocarbons in marijuana and tobacco smoke indicate a considerably higher content of potential carcinogens in the former. A model experiment involving delta9-tetrahydrocannabinol suggests that the pyrolysis products of cannabinoids are major contributors to the polynuclear aromatic hydrocarbons.