The Dose Makes the Poison, Even for Marijuana Smoke

[Herb Fellow]

In a recent study published by the journal Chemical Research in Toxicology, Health Canada researchers found higher levels of certain toxins in marijuana smoke than in tobacco smoke. The researchers used a smoking machine to compare cigarettes made from Players brand fine-cut tobacco with cigarettes made from cannabis produced by Prairie Plant Systems of Saskatoon, which grows medical marijuana under contract with Health Canada. The marijuana smoke had 20 times as much ammonia and five times as much hydrogen cyanide and nitrogen oxides, possibly due to higher levels of nitrate fertilizer traces in the marijuana. Then again, only the tobacco smoke contained the potent carcinogens known as tobacco-specific nitrosamines, and it had "moderately higher levels" of potentially hazardous compounds such as formaldehyde, acetaldehyde, and polycyclic aromatic hydrocarbons. Guess which comparison was emphasized in the press coverage.

"Cannabis smoke 'has more toxins,'" BBC News reported, warning that ammonia is "linked to cancer," while hydrogen cyanide and nitrogen oxides "are linked to heart and lung damage respectively." The Guardian agreed: "Cannabis smoke more toxic than puffing tobacco." Even EarthTimes ("Cannabis smoke more harmful than tobacco smoke") and New Scientist ("Inhaled cannabis is more toxic than tobacco smoke") went along with this gloss. But it's not what the researchers reported (emphasis added):

The combustion of any plant material will result in a complex mixture of chemicals, the composition and percentages of which depend on a large number of variables. The present study supports previous research and found that marijuana smoke contains qualitatively many of the same chemicals as tobacco smoke. This qualitative similarity is more important when assessing the risks for adverse outcomes than are the differences in level of a particular substance, which can change from sample to sample or from one smoking condition to another.

Even more important in assessing the health risks of pot smoking is a point that BBC News halfway acknowledged: While a joint a day would count as fairly heavy consumption for a pot smoker (since most pot smokers light up occasionally), the current mean for cigarette smokers is about 14 cigarettes a day (down from about 20 in 1993). This huge difference in dose is presumably the main reason pot smoking has not been linked to cancer, heart disease, or emphysema in epidemiological studies, despite the similarity between marijuana and tobacco smoke. Those still concerned about possible respiratory effects, of course, can avoid combustion products by using vaporizers (as do many patients who use marijuana as a medicine).

Addendum: A commenter asked about the efficacy of water pipes in reducing the hazards of pot smoking. They do not work nearly as well as vaporizers, partly because they filter out THC, encouraging people to smoke more for the same effect. Here is a report on research comparing water pipes to vaporizers, which says, "We learned early on that waterpipes don't help filter out undesirable particulate matter, although waterpipes may help reduce certain water-soluble gases."

Source: Reason Magazine
Copyright: 2007 Reason Magazine
Contact: Jacob Sullum
Website: Reason Magazine - Hit & Run > The Dose Makes the Poison, Even for Marijuana Smoke

[DaMagoMan]

Recon' I'll be hittin' the bong dry from Now on

And what's to say the THC doesn't offset the toxins ??? Hmmmm???

[ZedRules]

I use daily, morning to night when I off work & evenings during work days and use a Volcano, which I know reduces any threat of exposure to most of the chemicals described in the article. I hit a hash pipe 2-6 puffs to enhance my vape meds....that's where I assume the risk.

My concern about articles & a study such as had been mentioned, is that many people would jump to conclusions about the "evils" of cannabis, now thought to be worse than tobacco according to that Canadian study. How will this promote our cause....the simple fact is that most non-users associate pot with smoking, than with any other form of consumption....this bolsters the Feds argument about the plants worthlessness and justifies sending in DEA folk to reign terror down on someone who uses a substance that according to them has no medicinal value....I should be busted for watching the news....it has no medicinal value....hell they ought to lock up Bush, he is the single most valueless individual in Gov. history...definitely a Class Schedule 1 drug (Bush's relentless assualt on the truth).

[MildGreens]

Nicotine masks early onset of cancer from the immune system, whereas cannabis does not. The logic may defy redneck journalists, populist politicians and prohibitory police but the epidemiology evidence is in, it is exonerative, whereas the continuing 'research' delusion makes for injustice on a grand scale.

[DaMagoMan]

I think these articles fit real nice Here, in the Big Picture Thang.
HHMI Bulletin November 2007: The Changing Face of DNA

Rapid acceleration in human evolution described | Health | Reuters

cbs2.com - Study: Human DNA Less Alike Than Thought

I've always argued,
My desendents maybe able to live where your's can not in the furture
because I smoke today
Yes, Cancer runs in my family, lung and breast types.

Exposure to enviroment is passed to the next generation, in my Grows.

But what does a Non-educated Ol'HillBilly of a RedNeck like me know (smrk)
Sometimes you don't have to be taught , You just Know.
Proving it to Others is the Hard part

[Herb Fellow]

I think I need larger doses! There isn't much that you can eat, drink or breathe that is completely safe these days. All I know is that I benefit greatly from it's daily use and will continue to do so. It is the best mental health medication you can get and helps me deal with the pain of chron's. I don't think I've had enough to be poisoned. As a matter of fact, when was the last time you've heard someone poisoned by marijuana?

[southflorida]

I'll volunteer for any mj poisoning research btw.

[weedyMcBong]

im with south
and i agree with zed
a lot of people don't read between the lines anymore.
and will probably believe whatever it is they are spoon fed
believable or not.

[TMoney21]

...so tired of pot party poopers

[TMoney21]

Originally Posted by chameleon140

Huh? Me?

No no, not you chameleon...I was just referring to the article and the people who back their information with personal biases.

[Pants]

I have never in years and years gotten as high as when I'm bubbling -- I'm even friends with a really popular rock band. I was in their bus, and I smoked from the Volcano. I still get higher from my sweet glass bubbler. The point is, is that I smoke ONE HIT a day, if I'm lucky. A smoker smokes 13-20 cigarettes. It's just not a comparable vice.

You all are cool.