Pot doesn't have nicotine but it has just about everything else tobacco has, including a much higher tar content. Just saying pot isn't carcinogenic without any scientific back-up is meaningless and you don't know how many people have died from smoking pot because most pot smokers also smoke tobacco.
Well I can post pages and pages of rather dry reading if that's preferred but is there honestly a point to that? It's complex, and while pot is the third most widely used drug after Alcohol and Tobacco in North America, it is lacking in research due to the legality of the substance. Britain has done quite a bit more research on it's effects now but as legislation regarding the medical use allow for it, there are many current studies underway here in North America.
As it is, there is nothing that points to pot being more harmful than either legal substance mentioned. You can't over dose on pot for one thing. The only signs that there may be some harm from smoking pot is anecdotal and sparse. The cancer angle isn't much of a point to stand on. Read up on Cannabis and their effect on Cancer cells. I'm not saying it's good for you, but it's not a killer in the sense that Tobacco or Alcohol is.
What's more, now that there is some research going on with it, we are finding that things like vaporizers allow you to inhale the Cannabis without vaporizing the tar or other chemicals in Marijuana. Thus far less of what you say is deadly even gets ingested. This never would have happened under the harsh laws brought about by American proclamation.
You make a good point in keeping it away from kids. It should be too! But as it is we have organized crime for the most part involved in the distribution of it. So how smart is that? Yet the one thing that would change that, our government refuses to implement. Perhaps the courts will make the changes needed to get beyond this stupidity.
As it is there are plenty of kids that get pot from adults to deal in schools. If your kids and grandkids go to school outside the home, then they've seen it and can get a little bit for ten bucks without any problem at all. Five bucks even will get you a joint or two. Drop $180 and you can have a quarter ounce for your self and sell the other three quarters to get your $180 back.
There is no regulation of it what so ever.
The US alone spends 42 billion a year on the war on drugs. Ask anyone in a major centre if there is a shortage. Worse yet, half the people arrested for drugs are pot smokers. Crack and Crystal Meth are totally out of control, but the US is busy padding the numbers and busting the easy to catch pot smokers.
If you want to protect your kids and grandkids, teach them to fear the government.
Read up on some of this if you like.
Cannabis Smoke and Cancer: Assessing the Risk - NORML
