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Marijuana is the most commonly used illicit drug in America today. The term "marijuana" refers to the leaves and flowering tops of the cannabis plant.

A tobaccolike substance produced by drying the leaves and flowering tops of the cannabis plant, marijuana varies significantly in its potency, depending on the source and selection of plant materials used. Sinsemilla, which is derived from the unpollinated female cannabis plant, and hashish, the resinous material of the cannabis plant, are popular with users because of their high concentration of THC (delta-9-tetrahydrocannabinol). THC is believed to be the chemical responsible for most of the psychoactive effects of the plant.

Marijuana is usually smoked in the form of loosely rolled cigarettes called joints or hollowed-out commercial cigars called blunts. Joints and blunts may be laced with a number of adulterants including phencyclidine (PCP), substantially altering the effects and toxicity of these products. Street names for marijuana include pot, grass, weed, mary jane, acupulco gold, and reefer.

Although marijuana grown in the United States was once considered inferior because of its low concentration of THC, advancements in plant selection and cultivation have resulted in highly potent domestic marijuana. For example, the average THC content of U.S.-produced sinsemilla has risen from 3.2 percent in 1977 to 12.8 percent in 1997.

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.


Overall usage: The number of marijuana-related emergency room episodes, which are tracked by the Drug Abuse Warning Network (DAWN), has steadily increased from 15,706 in 1990, to 87,150 in 1999. Many of these visits can be attributed to the fact that the potency of marijuana has also increased during that same time period. The 1999 National Household Survey on Drug Abuse (NHSDA) estimated that 5.1 percent (11.2 million) of the population aged twelve and older were monthly marijuana or hashish users, which is the same rate as in 1991 but considerably lower than the rate of 13.2 percent in 1979. NHSDA also found that the number of first-time marijuana users in 1998 (2.3million) increased significantly compared to 1989 (1.4million). In addition, according to the Office of National Drug Control Policy's 1998 Drug Control Strategy, marijuana is the most prevalent illegal drug in the United States; approximately three-quarters (77percent) of current illegal drug users used marijuana or hashish in 1996.

Use among youth: The marijuana problem among youth is particularly acute. According to a survey conducted by Phoenix House, an organization that runs drug abuse treatment centers and conducts extensive research, marijuana was the drug of choice for 87 percent of teens entering treatment programs in New York during the first quarter of 1999. A 1996 national survey conducted by Phoenix House revealed that eighty-three percent of adolescents in treatment perceived, at one time or another, marijuana to be less dangerous than other illicit drugs, and 60 percent agreed that using marijuana made it easier for them to consume other drugs, including cocaine, methamphetamine, and LSD. Similar statistics were found by the 1999 Monitoring the Future study, which showed that marijuana is the illegal drug most frequently used by young people. Among high school seniors, 49.7 percent reported using marijuana at least once in their lives. By comparison, that figure was 41.7 percent for seniors in 1995 and 32.6 percent in 1992. The 1999 NHSDA found that nearly one in 13 youths aged 12-17 were current users of marijuana in 1999 and that the prevalence of marijuana use among youth more than doubled from 1992 to 1999. The 1998 National Center on Addiction and Substance Abuse study indicates that adolescents are first exposed and try marijuana at a very young age. According to the study, 50 percent of 13-year-olds reported that they could find and purchase marijuana, and 49 percent of teens surveyed said that they first tried marijuana at age 13 or younger.


Availability: Marijuana is readily available throughout all metropolitan, suburban, and rural areas of the continental United States.


United States: Domestic cannabis is frequently cultivated in remote locations and on public land to prevent observation and identification of owners. To curtail the spread of marijuana cultivation, the DEA initiated the Domestic Cannabis Eradication and Suppression Program in 1979, which is the only nationwide program that exclusively addresses marijuana. The program began operations in Hawaii and California and rapidly expanded to include all 50 states by 1985. In Hawaii, cannabis eradication efforts have reduced marijuana availability in the islands and forced traffickers to smuggle marijuana from the mainland. For additional information about this program, see the "Marijuana Eradication" section.

A trend toward indoor marijuana production in the United States is largely due to successful drug law enforcement efforts to curtail outdoor cultivation. Moreover, indoor growing provides a controlled environment conducive to the production of highpotency sinsemilla. Indoor cultivation permits yearround production and can be accomplished in a variety of settings. Indoor grows range from several plants grown in a closet, to thousands of plants grown in elaborate, specially constructed greenhouses. Rates of vegetation, growth, and maturation are enhanced by special fertilizers, plant hormones, steroids, insecticides, and genetic engineering. In 1998, the five leading states for indoor growing activity were California, Florida, Oregon, Alaska, and Kentucky. Indoor growers cultivated 89 plants on average. Nationwide in the same year, drug law enforcement authorities seized 2,616 indoor grow operations.

Other Countries: Drug trafficking organizations operating from Mexico are responsible for supplying most of the foreign marijuana available in the United States. However, traffickers based in countries in the Far East, such as Cambodia and Thailand, also cultivate and ship marijuana to the United States. Marijuana from Thailand, which is often referred to as "Thai sticks," is seized much less frequently than marijuana originating from Mexico.


Virtually all marijuana is smuggled into the United States concealed in false compartments, fuel tanks, seats, and tires of private and commercial vehicles, pickup trucks, vans, mobile homes, and horse trailers. Larger shipments, up to multi-thousand kilogram amounts, usually are smuggled in tractor-trailer trucks in false compartments and among legitimate bulk shipments, such as agricultural products. U.S. authorities seized a record 593 metric tons of marijuana along the Southwest Border in 1997 - approximately 25 percent more than that seized in 1996 and nearly double that seized in 1995. With increased law enforcement pressure along the Southwest Border of the United States, marijuana smugglers are shifting to traditional routes in the Gulf of Mexico and the Bahamas. They use cargo vessels, pleasure boats, and fishing boats to sail up the coast of Mexico, either to U.S. ports or drop-off sites along the U.S. coast and the Bahamas.

Review a cura del Gruppo Evelink - release dicembre 2000 - Fonti: CD-ROM "Stupefacente", a cura della Guardia di Finzanza; Il sito ufficiale dell'UNOCCP (United Nations Office for Drug Control and Crime Prevention); Medline

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