The US DEA, in a Nov. 2001 publication DEA Briefing Book, Drugs of Concern, wrote:

“Marijuana contains known toxins and cancer-causing chemicals that are stored in fat cells of users for up to several months. Marijuana users experience the same health problems as tobacco smokers, such as bronchitis, emphysema, and bronchial asthma. Some of the effects of marijuana use also include increased heart rate, dryness of the mouth, reddening of the eyes, impaired motor skills and concentration, and frequent hunger. Extended use increases risk to the lungs and reproductive system, as well as suppression of the immune system. Occasionally, hallucinations, fantasies, and paranoia are reported.”

Nov. 2001