We know that cannabis smoke contains a bunch of the same carcinogens as tobacco smoke. But tobacco smokers smoke a lot more than cannabis smokers; and you don't have to smoke cannabis.
http://medicalmarijuana.procon.org/view.answers.php?question...
The interesting one is:
> Dale Gieringer, PhD, State Coordinator of the California National Organization for the Reform of Marijuana Laws (NORML), stated in his 2004 article "Cannabis Vaporizer Combines Efficient Delivery of THC with Effective Suppression of Pyrolytic Compounds," published in the Journal of Cannabis Therapeutics, where he compared the chemical constituents of marijuana smoke (from a glass pipe) with marijuana vapor (from a vaporizer machine):
[...]
> Comparison runs using combusted [burned] cannabis presented a strikingly different picture... Review data from the gaseous headspace detected 111 tentatively identified compounds, including THC and CBN. Included were five known PAHs [polynuclear aromatic hydrocarbons]. Cannabinoids represented only 12% of the inferred recovered mass; the remaining 88% consisted of extraneous products of combustion."
And that is followed by a different study:
> 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:
> 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."
That's your interpretation, but it's not my assertion.
I've long wondered where the measurable health impact of marijuana smokers is. At the rates Americans consume it, shouldn't we be able to measure it the way we measure effects of tobacco and alcohol? Or is that more opportunity lost to prohibition?
I think the answer to "do we know that?" was "yes, we know that."
You begin with the plant, extract the molecules that you want, and then vaporize said extract. Filter this vaporization through water since the molecules that you want aren't water soluble. This also cools down the vapours.
It is a lot safer than blindly setting a plant on fire.
The downside is that you will pay a premium in order to get quality medicinal extracts and you will need to invest money ($500+) in order to get a decent vaporizer.
Source: I am no expert, but I have family members that use cannabis as a legal medication.
http://medicalmarijuana.procon.org/view.answers.php?question...
Erowid has a nice chart. See benzene. https://www.erowid.org/plants/cannabis/cannabis_info3.shtml
The british pro-drug site has a summary of some research: http://www.ukcia.org/research/smoke-contents.php
This UK National health service "behind the headlines" report looks at one study and how it was reported. http://www.nhs.uk/news/2012/06june/Pages/cannabis-lung-healt...
> The report says that the constituents of cannabis smoke are similar to those of tobacco smoke apart from the presence of THC (which is only in cannabis) or nicotine (which is only in tobacco). This means that cannabis smoke has the same carcinogens (substances that cause cancer) as tobacco smoke, although concentrations of these may be up to 50% higher. Like tobacco, cannabis also contains toxic carbon monoxide.
> It also points out that although people generally smoke cannabis less often than tobacco cigarettes, the way they inhale means the amount of smoke reaching the lungs is greater. The respiratory tract and the rest of the body may also retain far more of the products of cannabis smoke than when smoking a similar quantity of tobacco. Given the similarities in their constituents, there is concern that regularly smoking cannabis could have similar health risks as regular tobacco smoking, says the BLF.
> Also, people often mix cannabis with tobacco. There is strong evidence that smoking tobacco causes lung cancer and chronic lung disease. This makes it difficult to isolate whether health problems are specifically caused by cannabis or tobacco, says the report.