Marijuana smoke contains higher levels of certain toxins than tobacco smoke

December 17, 2007
Marijuana smoke contains higher levels of certain toxins than tobacco smoke
Marijuana smoke contains higher levels of several toxic compounds, including ammonia and hydrogen cyanide, than tobacco smoke. Credit: U.S. Drug Enforcement Administration

Here’s another reason to “keep off the grass.” Researchers in Canada report that marijuana smoke contains significantly higher levels of several toxic compounds — including ammonia and hydrogen cyanide — than tobacco smoke and may therefore pose similar health risks.

Their study, termed the most comprehensive to date on the chemical content of marijuana smoke, is scheduled for the Dec. 17 issue of ACS’ Chemical Research in Toxicology, a monthly journal.

David Moir and colleagues note that researchers have conducted extensive studies on the chemical composition of tobacco smoke, which contains a host of toxic substances, including about 50 that can cause cancer. However, there has been relatively little research on the chemical composition of marijuana smoke.

In this new study, researchers compared marijuana smoke to tobacco smoke, using smoking machines to simulate the smoking habits of users. The scientists found that ammonia levels were 20 times higher in the marijuana smoke than in the tobacco smoke, while hydrogen cyanide, nitric oxide and certain aromatic amines occurred at levels 3-5 times higher in the marijuana smoke, they say.

The finding is “important information for public health and communication of the risk related to exposure to such materials,” say the researchers.

Source: ACS

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4.5 / 5 (2) Dec 17, 2007
This really isn't news. And it was made moot years ago with the advent of vaporizers.

However, further development of such non-smoked delivery systems for medical use has been seriously hindered by DEA's illegal obstruction of the effort to establish a standardized, quality-controlled, contaminant-free supply of marijuana for medical research.
3 / 5 (2) Dec 17, 2007
and as we all know, the hospitals are full of long term potheads suffering serious lung diseases...
not rated yet Jan 24, 2008
This study is bogus, read it and youll see. the main problem with it is first the weight. the machine smoked 30 cigarettes of tobacco and pot. both weighted at around 780mg (0.7gram) first note that a normal cigarette weights around 2.2 grams (remove up to .4 for the weight of the filter)

now, the total of 20% more chemicals coming from the marijuana is calculated at the end of the 30 joint smoking session.
total pot smoked by the machine 21 gram
total tobacco smoked by the machine 21 gram

now THINK .. i defy anyone here, the most hardcore smokers, to smoke 21 gram of weed a day, really. its ludicrous. nobody does that, ever.

do people smoke up to 30 cigs/day ? very very common. so take this down to a more reasonable level.. hardcore smokers will go from 1-3 gram a day. and now remember that i said that a cigarette weights about 2.5gram .. about 3 times more than the amount used in the study.

do i need to explain more ? i hope not.

This was never about health issues. Else tobacco would be illegal. If it was about health issue, why hasnt the country provided us with pure THC already so we can stop smoking all that nasty crap thats in the plant material?

nobody is concerned about your health. not even those who think they do.
not rated yet Oct 02, 2008
and as we all know, the hospitals are full of long term potheads suffering serious lung diseases...

And where does this information come from, several top schools have very plainly said smoking marijuana does not increase chances of lung cancer even with the carcinogenic matter or the throat. Ciggarets have zero positive influence to counteract the damage they do by smoking them
not rated yet May 15, 2009
He was being sarcastic.

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