Your still stupid*
Donald P. Tashkin, MD, Director of the Pulmonary Function Laboratories at the University of California, Los Angeles, stated in his article "Effects of Marijuana on the Lung and its Immune Defenses," published in the Mar. 1997 "Secretary's Youth Substance Abuse Prevention Initiative: Resource Papers" by the Center for Substance Abuse Prevention:
"Analysis of the smoke contents of marijuana and tobacco reveals much the same gas phase constituents, including chemicals known to be toxic to respiratory tissue. Moreover, these gas phase components are present in somewhat similar concentrations in the smoke generated from the same quantity of marijuana and tobacco.
The particulate phase (tar) constituents of marijuana and tobacco smoke are also generally similar, with the major exception that marijuana contains tetrahydrocannabinol (THC) and scores of other llIC-like (cannabinoid) compounds not found in tobacco, while tobacco tar contains nicotine not found in marijuana.
With regard to the carcinogenic potential of marijuana, it is noteworthy that the tar phase of marijuana smoke contains many of the same carcinogenic compounds contained in tobacco smoke, including polycyclic aromatic hydrocarbons, such as benz[a]pyrene, which was recently identified as a key factor promoting human lung cancer... Preliminary findings suggest that marijuana smoke activates cytochrome P4501A1, the enzyme that converts polycyclic hydrocarbons, such as benz[a]pyrene, into active carcinogens."