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Cannabis Research - Safety

Marijuana Use and the Risk of Lung and Upper Aerodigestive Tract Cancers: Results of a Population-Based Case-Control Study

Background: Despite several lines of evidence suggesting the biological plausibility of marijuana being carcinogenic, epidemiologic findings are inconsistent. We conducted a population-based case-control study of the association between marijuana use and the risk of lung and upper aerodigestive tract cancers in Los Angeles.
Methods: Our study included 1,212 incident cancer cases and 1,040 cancer-free controls matched to cases on age, gender, and neighborhood. Subjects were interviewed with a standardized questionnaire. The cumulative use of marijuana was expressed in joint-years, where 1 joint-year is equivalent to smoking one joint per day for 1 year.
Results: Although using marijuana for z30 joint-years was positively associated in the crude analyses with each cancer type (except pharyngeal cancer), no positive associations were observed when adjusting for several confounders including cigarette smoking. The adjusted odds ratio estimate (and 95% confidence limits) for z60 versus 0 joint-years was 1.1 (0.56, 2.1) for oral cancer, 0.84 (0.28, 2.5) for laryngeal cancer, and 0.62 (0.32, 1.2) for lung cancer; the adjusted odds ratio estimate for z30 versus 0 jointyears was 0.57 (0.20, 1.6) for pharyngeal cancer, and 0.53 (0.22, 1.3) for esophageal cancer. No association was consistently monotonic across exposure categories, and restriction to subjects who never smoked cigarettes yielded similar findings.
Conclusions: Our results may have been affected by selection bias or error in measuring lifetime exposure and confounder histories; but they suggest that the association of these cancers with marijuana, even long-term or heavy use, is not strong and may be below practically detectable limits. (Cancer Epidemiol Biomarkers Prev 2006;15(10):182934)

Institute of Medicine Report, Marijuana and Medicine: Assessing the Science Base, 1999 - National Academy of Sciences

Public opinion on the medical value of marijuana has been sharply divided. Some dismiss medical marijuana as a hoax that exploits our natural compassion for the sick; others claim it is a uniquely soothing medicine that has been withheld from patients through regulations based on false claims. Proponents of both views cite "scientific evidence" to support their views and have expressed those views at the ballot box in recent state elections. In January 1997, the White House Office of National Drug Control Policy (ONDCP) asked the Institute of Medicine to conduct a review of the scientific evidence to assess the potential health benefits and risks of marijuana and its constituent cannabinoids. That review began in August 1997 and culminates with this report.

Drugs and the Law. Report of the Independent Inquiry into the Misuse of Drugs Act 1971 (1999)

It is nearly 30 years since the main legislation controlling the misuse of drugs in the United Kingdom was enacted. Our task has been to consider the changes which have taken place in our society in that time and to assess whether the law as it currently stands needs to be revised in order to make it both more effective and more responsive to those changes. It has also been our duty to examine the implications of our proposals.

Marijuana, Alcohol and Actual Driving Performance - U.S. Department of Transportation, National Traffic Safety Administration, DOT HS 808 939, July 1999

The purpose of this study was to empirically determine the separate and combined effects of Delta 9 tetrahydrocannabinol (THC) and alcohol on actual driving performance. This was the first study ever in which the drugs' combined effects were measured in a natural setting, i.e., on real roads in normal traffic.

Advisory Council on the Misuse of Drugs, U.K., 2002

The Classification of Cannabis Under the Misuse of Dugs Act 1971. Commissioned by the British Home Office in October of 2001. Submitted in March, 2002.

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