You might be surprised to learn that marijuana contains the same cancer-causing chemicals as tobacco, and at higher concentrations. Smoking five joints a week is the equivalent of smoking an entire pack of cigarettes every day which, even in the short term, leads to lung and respiratory problems-wheezing, frequent chest colds and-yick!-a nasty phlegmmy cough. Long-term use increases the chances of tissue damage and lung cancer, and also causes changes in the brain similar to those caused by long-term use of cocaine and heroin.
I thought this was interesting:
Several studies have linked marijuana use with poor school performance. It's harder to concentrate and retain information when you've been using pot, and every day of school is important to teens in their peak learning years. It should be no surprise that the National Household Survey on Drug Abuse found teens with a "D" average or below more than four times as likely to have used marijuana in the last year than those with an "A" average. You're more likely to drop out - or get kicked out - of school, or out of sports or other activities if you smoke marijuana.
Ok, now I'll post some info supporting weed:
Memory
Marijuana does impair short-term memory, but only during intoxication. Although the authoritative studies on marijuana use seem to agree that there is no residual impairment following intoxication, persistent impairment of short-term memory has been noted in chronic marijuana smokers, up to 6 and 12 weeks following abstinence
Marijuana Overdose
There is no existing evidence of anyone dying of a marijuana overdose. Tests performed on mice have shown that the ratio of cannabinoids (the chemicals in marijuana that make you high) necessary for overdose to the amount necessary for intoxication is 40,000:1.
For comparison's sake, that ratio for alcohol is generally between 4:1 and 10:1. Alcohol overdoses claim approximately 5,000 casualties yearly, but marijuana overdoses kill no one as far as any official reports.
Now, to be fair, I have to critisize both articles. The credibility and accuracy of the paragraph on low school grades is questionable, considering all the kids who might lie about it. However, it's proven that they have found the same cancer causing agents as in tobacco.
In the supporting weed articles, the amount of weed needed to overdose is insignificant considering it's the side affects, aswell as some cancer causing agents that will harm you. On paper, saying that weed has 0 deaths sounds great, but you have to consider how hard it is to judge a death as marijuana-provoked.