The long-term physiological and psychological effects of smoking pot are complicated. Further clouding this issue is the absence of a clear definition of "light," "moderate," and "heavy" use. Based on a range of research, however, a few joints a year can be considered light use, lighting up a few times a month constitutes moderate use, and daily hits or multiple uses per week spell heavy use. The duration of marijuana use over time may be the major player when it comes to unhealthy effects: long-term, heavy use of the drug may result in the illnesses and diseases associated with long-term cigarette smoking. Cigarettes have been linked to an increased incidence of heart disease and lung cancer (marijuana smoke contains the same cancer-causing chemicals as tobacco smoke -- actually four times as much tar); emphysema; gum disease; and cancers of the mouth, jaw, and tongue.
Additionally, short-term memory loss, reduced fertility in men and women, and personality changes may occur in some long-term pot smokers. The more immediate effects of moderate and heavy marijuana use are better known: congestion, sore throat, dry mouth, impaired thinking and motor skill ability (including reaction time essential for driving), fatigue, anxiety, dilated pupils, and more. Some research links a rare childhood leukemia with mothers who lit up while they were pregnant.
Storage-wise, about half of the marijuana metabolites -- the substances that result from pot's breakdown by the liver and kidneys -- pass through the body hours after the first hit. The rest of the metabolites are stored away, sometimes for weeks, in fatty tissue, where their effect is unknown. We do know that pot, by itself and not when it is combined with other unknown substances, is not physically addictive, nor does it appear to impair intelligence.
Is pot more dangerous than alcohol? On an individual level, it depends on many factors, including reasons for use (as part of a healthy celebration, or as an unhealthy coping crutch), family history of alcohol and other drug use (drugs are often more dangerous if one or both parents are/were abusers), and your comfort level in the environment and situation in which drug use occurs.
Let's go somewhere else with your pot query. Like cigarettes, pipes, and cigars, joints and bongs deliver second-hand smoke to nonusers around them -- through the air, under doors, and via air vents. And, a nonsmoker in a very smoky room theoretically can get high, too. Likewise, urine can test positive via a drug test for innocent bystanders within a day of breathing second-hand pot smoke. Weed and other drug use can also impact relationships with friends, roommates, parents, etc., in ways that you might not have predicted before you lit up.
P.S.:
Drug-Related Deaths in the United States
Every year in the United States, alcohol-related deaths total 100,000 and tobacco-related fatalities total 450,000. And, according to the Feds, all illicit drugs are linked to under 10,000 deaths per year. But, according to the New York State Office of Alcoholism and Substance Abuse Services, "innocent" pot is increasingly laced with other drugs, like angel dust and heroin, sometimes unbeknownst to users. Obviously, mixing drugs can present big problems -- even to first-time users.
