Re: “Marijuana legislation will not achieve its objectives and should be defeated," (The Hill Times, online, Dec. 20, 2017). There are so many unsubstantiated or categorically false claims in Conservative Senator Betty Unger’s opinion piece that selecting only a few to discuss seems an impossible task. As we have already seen countless times by her elected Conservative counterparts in Bill C-45 debates in the House of Commons, Sen. Unger relies on an incomplete representation of Colorado state trends to support the claim that cannabis use among youth increased after legalization. Did the per cent of youth who uses cannabis increase after legalization? Yes, by one per cent. In population health research, this would rarely be considered a meaningful increase (i.e., a change that was not due to chance alone). In fact, a recently-published peer-reviewed study confirmed, by comparing rates over time to neighbouring non-legalized states, that cannabis legalization did not lead to increased use among high school students in Colorado. Instead of relying on known legalization opponents like Kevin Sabet to support her claims, why not look to public health experts on the ground in Colorado? Dr. Larry Wolk, director of the Colorado Department of Public Health and Environment, recently described a lack of any significant public health issues arising from legalization, including changes in youth use. Sen. Unger also casually tossed in a health claim that would have public health experts everywhere scratching their heads: that “smoking marijuana is far more harmful to your health than smoking cigarettes." It’s unclear where Sen. Unger received this bit of health information. Perhaps it came from Stephen Harper’s infamous 2015 election claim that “marijuana is infinitely worse ," but it was unlikely to have come from anyone in the fields of medicine or public health. In fact, many public health experts are in agreement that cannabis is less harmful to self and others than either tobacco or alcohol. The causal link between cigarettes and lung cancer, cardiovascular disease, and several other life-threatening diseases is so strong and consistent, it is considered fact; meanwhile, the National Academies of Sciences, Engineering, and Medicine’s extensive review concludes that the current state of evidence does not support a causal link between cannabis and lung cancer. The report concluded there is insufficient evidence to support or refute an association between cannabis and all-cause mortality. Bold policy moves entail risk. Legalization will not be perfect, but it will be far from “horrible." Unfortunately, Sen. Unger has demonstrated what C-45 will be up against in the Senate: misrepresentation of evidence, invention of alternative facts, and the use of fear-mongering to support an ideological position against cannabis legalization. These tactics are old, and they shouldn’t stand a chance against the state of the evidence. Stephanie Lake Pierre Elliott Trudeau Foundation doctoral scholar in the School of Population and Public Health, University of British Columbia Vancouver, B.C. Rebecca Haines-Saah assistant professor, Department of Community Health Sciences, Cumming School of Medicine, University of Calgary Calgary, Alta.