There's a great column in the Tennessean today from NORML deputy director and "Marijuana is Safer" co-author Paul Armentano.

Here's an excerpt, or you can read entire piece HERE:

And unlike alcohol and tobacco, adverse effects of even heavy cannabis use are minimal. There is no epidemiological evidence in any country, after scores of studies and centuries of use by tens of millions of people, that marijuana smokers have a shorter life expectancy than non-smokers.

They don’t become violent at sports events or beat their spouses and children. They don’t get heart disease, cancer, brain damage or any other deadly illness at a higher rate than those who abstain. In fact, a pair of studies conducted by Kaiser Permanente found that marijuana use, even long-term, was not associated with elevated levels of mortality or incidences of cancer, including types of cancers associated with tobacco smoking.