Marijuana is the most commonly used illicit drug in America today. It contains known poisons and cancer-causing chemicals that are stored in users' fat cells for up to several months. Marijuana users experience the same health problems as tobacco smokers, such as bronchitis, lung cancer, and asthma. Some of the effects of marijuana use also include increased heart rate, dryness of mouth, reddening of the eyes, impaired motor skills and concentration, and frequent hunger. Extended use increases risk to the lungs and reproductive system. -Information from the DEA Web site