According to a carcinogenic tar study in the late 1970s, Berkeley determined that “marijuana is one-and-a-half times as carcinogenic as tobacco.” All this study did was compare the amount of tar present in cannabis leaves, and compared it to tobacco. The study didn’t take into account a number of things, but first I must explain about the radioactivity found in cigarettes that isn’t present in marijuana.

Tar is not what causes cancer, that conclusion is just a side effect of tobacco companies marketing their cigarettes. U. S. Surgeon General C. Everette Koop said on national television in 1990 that radioactivity, not the tar, accounts for at least 90% of all smoking related lung cancer. Now I’m sure you’re wondering how the radioactivity gets in the cigarettes in the first place.

By law tobacco crops grown in the United States are required to be fertilized with phosphates are rich in radium 226. Also radium 226 occurs naturally in many soils. Over time the radium 226 breaks down into two long lived daughter elements, lead 210 and polonium 210. When the radioactive particles become airborne they attach themselves to fine hairs on the tobacco leaves.

Studies show lead 210 and polonium 210 accumulating in people’s bodies that are exposed to cigarette smoke, and that smokers have three times as much lead 210 and polonium 210 deposits in their lower lungs than non smokers. As well as they have greater concentrations of lead 210 and polonium 210 in their skeletons, but no studies have been proven to link this to bone cancer. Polonium 210 has been proven to produce tumors by itself in inhalation experiments with animals.

Marijuana tars do not contain radioactive materials like lead 210 and polonium 210. And the studies do not consider that:

Most marijuana smokers smoke the bud and not the leaf of the plant. In fact it’s hard to find the leaf of a plant to smoke unless you grow your own, or know somebody who does.
Marijuana smokers do not smoke anywhere near the amount that cigarette smokers do. After a blunt or a joint, or maybe a couple bowls they’re good to go for a few hours, and most people don’t really smoke more than once a day, while cigarette smokers on the other hand smoke up to a pack a day, usually at least one cigarette every 2 hours, and if they’re stressed out they may smoke a lot more.

Not one case of lung cancer has been successfully linked to marijuana use.

Marijuana does not cause any narrowing of the small air passageways in the lungs. Tobacco has that effect on lungs as well as the lead 210 and polonium 210 becomes attached to small irritated areas in the lungs. Tobacco smoke constricts the bronchi for long periods of time thus reduce the lung’s ability to clear itself of the radioactive elements.

Marijuana smoke actually does the opposite, studies show that marijuana has the ability to clear the lungs of smog, pollutant and cigarette smoke. Marijuana smoke is an expectorant and dilates the air channels that it comes in contact with. That is why sufferers of asthma use marijuana for relief. Those who heavily smoke cigarettes will live seven to ten years longer if they also smoke marijuana. Cannabis smokers have actually been shown to outlive nonsmokers by two to three years.