Quote Originally Posted by AlwaysBlazed
Marijuana causes cancer? 4 times as much tar as a cigarette? Lung cancer is 90% of the time causes by radiation which happens from smoking cigarettes, not tar.
Lung cancer is caused by not only the radioactive particles but also from tar and other carcinogens in tobacco.

As far as MJ causing cancer, there's real good evidence that the THC in cannabis has a cancer-protective/preventative effect. But anti-cannabis ad campaigns either won't hear that or don't want to know that. They certainly don't want to advertise that because it doesn't serve their purpose.

The detail about marijuana containing more carcinogens/tar than cigarette smoke, is, I'm afraid, true, and this is a hard-to-understand fact. In numerous tests, cannabis smoke has been found to be very dirty, carcinogenic smoke--containing more carcinogenic chemicals than tobacco smoke. I'm explaining this here because this is information that's worth communicating and understanding. It's dirtier smoke, and yet it's not associated with an increase in lung cancer or higher rates of head or neck cancers, either. That seems to be because it contains THC, which appears to have strong anti-cancer, anti-inflammatory properties. So weed smokers--and even cigarette smokers who also use weed--seem to derive some remarkable protective benefits from cannabis, even if the cannabis smoke they're inhaling has higher amounts of carcinogens than regular tobacco smoke. This hasn't been tested yet at high enough rates for people who smoke cigs or have had, say, heavy exposure to second-hand cigarette smoke to go out and begin smoking lots of weed to prevent any future lung cancers, but it's very promising information. THC and the other cannabinoids are amazingly beneficial chemicals.