I didn't include a direct link to the part of site because the image that came up I thought was inappropriate.
I. Marijuana smoke contains higher levels of carcinogenic polycyclic aromatic hydrocarbons (PAH) than those found in tobacco smoke.
As a rule, the level of carcinogenic PAHs within a chemical mixture is less important than the overarching influence of the mixture on carcinogenic PAH activation (Mahadevan et al. 2007). Indeed, marijuana smoke is presumed carcinogenic not only because it contains carcinogenic PAHs, but also because cannabinoids, in their own right, influence the cytochrome enzymes (CYP1) that determine carcinogenic PAH activation (Roth et al. 2001). Perhaps due to their phenolic hydrocarbon structure, cannabinoids share the anti-carcinogenic disposition of polyphenols to increase levels of CYP1A1 messenger RNA while competitively reducing CYP1A1 enzyme ativity through aryl hydrocarbon receptor ligation (Ciolino et al. 1998). Not surprisingly, spiking tobacco tar with delta-9 THC markedly reduced carcinogenic activity (Roth et al. 2001).
I read this as the chemical compound is present.