An intriguing study was published last week in the journal Chemical Research

in Toxicology assessing the concentrations of respiratory pollutants

produced by marijuana combustion to those produced by smoking tobacco.

Fortunately, folks can download the entire text of the study and read it for

themselves here:

Colleagues,An intriguing study was published last week in the journal Chemical Researchin Toxicology assessing the concentrations of respiratory pollutantsproduced by marijuana combustion to those produced by smoking tobacco.Fortunately, folks can download the entire text of the study and read it forthemselves here:"A comparison of mainstream and sidestream marijuana and tobacco cigarettesmoke produced under two machine smoking conditions"Unfortunately, it appears that few if any reporters actually did this beforepenning widely disseminated articles such as this one:Study Shows Toxins In Marijuana SmokeDec 17, 2007(WebMD) New research from Canada shows that some toxins may be more abundantin marijuana cigarettes than tobacco cigarettes.The researchers burned 30 marijuana cigarettes and 30 tobacco cigarettes ona machine in their lab, measuring levels of chemicals in the smoke.Ammonia levels were up to 20 times higher in marijuana smoke than in tobaccosmoke. Levels of hydrogen cyanide and nitrogen-related chemicals were threeto five times higher in marijuana smoke than in tobacco smoke.The nitrogen-based fertilizer used on the marijuana plants -- which all camefrom the same batch of Canadian pot plants -- may have affected the results.The temperatures used to burn the cigarettes may also have been a factor.Marijuana smoke and tobacco smoke shared many of the same chemicals. But thetwo types of smoke weren't identical.For instance, marijuana doesn't contain nicotine. And tobacco doesn'tcontain cannabinoids, which include THC, marijuana's active ingredientTobacco has long been linked to cancer and other health problems. Marijuanasmoke hasn't been tied to cancer in the past, note theresearchers, who included David Moir of the Safe Environments Programme inKitchener, Ontario.Moir and colleagues report their findings in the advance online edition ofChemical Research in Toxicology.They promise to compare the toxicity of marijuana smoke and tobacco smoke inanimals in another study.By Miranda HittiReviewed by Brunilda Nazario©2007 WebMD, Inc. All rights reserved.A few comments responding to this news item that are apparent reading thestudy:1) Investigators reported that mainstream marijuana smoke contained lowerlevels of selected polycyclic aromatic hydrocarbons (cancer causing agents)compared to tobacco.2) Nicotine, tobacco-specific nitrosamines, arsenic, and lead were notpresent in marijuana smoke.3) HCN forms from protein at temperatures above 700 degrees C, and wouldlikely be reduced or eliminated by vaporization.4) Clinical trials have shown that vaporization -- whereby marijuana isheated to a temperature where active cannabis vapors form, but below thepoint of combustion -- can greatly reduce or eliminate the presence of manypolycyclic aromatic hydrocarbons. Most recently, investigators at SanFrancisco General Hospital reported in the journal Clinical Pharmacology &Therapeutics that the "vaporization of marijuana does not result in exposureto combustion gases, ... and is preferred by most subjects compared tomarijuana cigarette." A previous clinical trial published in 2006 in theJournal of Pharmaceutical Sciences reported that vaporization is "safe andeffective" cannabinoid delivery system that "avoid[s] the respiratorydisadvantages of smoking.²5) The higher presence of ammonia, HCN, and aromatic amines(nitrogen-related chemicals) in marijuana were likely all due to the factthat Prairie Plant Systems cultivated the pot used in the trial with a highnitrate fertilizer. (By contrast, the tobacco used in the study was nottreated with a similar fertilizer.) I know that in the past PhilippeLucas/The VICS has been outspoken in his criticism of Prairie Plant Systemsgrow techniques, and I'd imagine that these latest findings will only addfuel to his fire.Best Regards,--Paul ArmentanoSenior Policy AnalystNORML | NORML FoundationPS: Folks can look for a full review of this study in Thursday's NORMLweekly media advisory, as well as on the NORML podcast.