Health committee  I thank the chair and members of the Standing Committee on Health for their invitation to present a few facts and interpretations on the topic of marijuana and health. My remarks will give special reference to young users. Marijuana is not the most dangerous of drugs. There are no proven deaths attributable to overdose, and millions of people have used it in small doses and on infrequent occasions with no obvious adverse effects.

Health committee  I should explain that I'm a professor of pharmacology in the faculty of medicine at the University of Toronto. I was director of biological and behavioural research at the Addiction Research Foundation of Ontario, which is now part of the Centre for Addiction and Mental Health. My research since 1959 has been largely on alcohol and cannabis.

Health committee  It's surely not for me to comment on the task of the committee. I take no part in that.

Health committee  Alcohol has been used since before the beginning of human history. Attempts to stop its use have been carried out from time to time in various countries, and in some countries it is not used for religious reasons. However, attempts to prevent its use for non-medical reasons in our society have failed.

Health committee  It was since 1959.

Health committee  I would be happy to give the clerk follow-up information. I can say that, in general, certainly alcohol is much more widely used than cannabis, and not surprisingly, it also causes serious health problems, more than cannabis, because of its wider use. The question of why it's allowed is a different matter altogether.

Health committee  History, tradition, social beliefs and practices play a major role in what society does or does not tolerate.

Health committee  Dr. Kahan did touch on it, Mr. Chairman. I will rely on you to direct questions to Dr. Kahan or to me, as you see fit.

Health committee  You raise a very good point. All the current uses that have been tested—not all have been approved—for which some evidence exists of a beneficial effect of cannabis, it is not the most effective, the most potent, or the most reliable drug. However, some patients don't respond even to the best drugs, and for those patients cannabis can be a useful fallback.

Health committee  I would just like to add a very brief comment to what Dr. Kahan has said. The difference between smoking and oral use of cannabis or pure cannabinoids is that when you inhale the cannabis containing the THC it is absorbed into the blood and reaches the brain more rapidly than when it's taken by mouth.

Health committee  Well, certainly I agree with the view that giving criminal records—especially to young people whose lives are all ahead of them—for possession of small amounts for personal use is not a benefit to society. On the other hand, legalization is not the same thing as decriminalization.

Health committee  Well, I would use alcohol as an example of how unsatisfactory regulation has been under a legal status. Young people use alcohol much more than one would like to see, yet it is a legal drug. It's simply the case that older people above the legal age for purchasing share it with the younger people.

Health committee  The cannabis that was available for illicit purchase at the time of the Le Dain commission was in the order of 0.5% to 1% THC. That was the material that was supplied to us from seized material by the RCMP when we began our studies. The current average for seizure material is between 10% and 15%.

Health committee  If you're talking about smoking, the onset of action is almost immediate. The concentration in blood rises rapidly for about the first 10 to 15 minutes. Then it levels off while the concentration in the tissues continues to increase, because the solubility of THC in fatty materials means that it tends to leave the blood and accumulate in the tissues.

Health committee  I want to make clear that what I said was that no deaths have been proven from overdose alone.