Sept 2018 BOH - Cannabis Legalization Update Report (BH.01.SEP0518.R26)

To: Chair and members of the Board of Health
Meeting date: September 5, 2018
Report no.: BH.01.SEP0518.R26
Prepared by: Kyley Alderson, Health Promotion Specialist, Health Communities and Public Policy; Patty Montague, Health Promotion Specialist, Health Protection; Tori Walters, Public Health Inspector, Health Promotion; Michael Whyte, Health Promotion Specialist, Health Analytics; Amy Estill, Interim Manager, Healthy Communities and Public Policy; Shawn Zentner, Manager, Health Protection; 
Approved by: Christopher Beveridge, Director, Health Protection; Rita Isley, Director, Community Health and Wellness and CNO
Submitted by: Dr. Nicola J. Mercer, MDMBAMPHFRCPC, Medical Officer of Health and CEO

Recommendations

It is recommended that the Board of Health:

  1. Receive this report for information.
  2. Send a letter to the Ontario Government encouraging them to: 1) provide ongoing dedicated funding to local public health agencies to support local cannabis-related programming and enforcement, 2) involve Public Health in future cannabis policy and programming decisions.

Key Points

  • On October 17, 2018 it will be legal in Canada to purchase, possess, and use cannabis for non-medical reasons. The Cannabis Act aims to keep cannabis out of the hands of youth, profits out of the hands of criminals, and protect public health and safety by allowing adults access to safe, legal cannabis.1
  • Access to medical cannabis will not change during this time and is regulated strictly at thecFederal level.
  • Cannabis will be available for purchase in Ontario online through the Ontario Cannabis Store (OCS). New legislation will be introduced to allow private retail stores to sell cannabis starting on April 1, 2019. The province will be conducting consultations prior to this.
  • The minimum age to purchase, possess, and cultivate cannabis in Ontario will be 19 years of age.
  • Use of cannabis will be restricted to private residences.
  • Possession of cannabis will be limited to 30 grams of dried cannabis. Adults will also be able to cultivate up to four plants per residence (not per person).
  • It will remain illegal to drive while impaired by cannabis and strict penalties will be imposed on those found driving impaired.
  • Local data on cannabis use and harms are currently limited. 22% of Grade 10 students in WDG have used cannabis in the past year. Cannabis-related Emergency Department (ED) visits among Wellington-Dufferin-Guelph (WDG) residents are higher among youth than adults over the age of 25.
  • Wellington-Dufferin-Guelph Public Health (WDGPH) is currently involved in several local initiatives to address cannabis legalization including: data collection activities to increase our understanding of cannabis use and outcomes, public education to support youth and adults to make informed decisions about cannabis use, and policy support to municipalities.
  • Evidence from other jurisdictions that have legalized cannabis should be interpreted with caution because of a lack of pre-legalization data with which to compare post-legalization data.

Discussion

Legislative framework

Federal

Medical

Through an exemption to the Controlled Drugs and Substances Act, access to dried cannabis for medical purposes was made legal in 1999. Under the authorization of a health care practitioner, individuals have been able to access dried cannabis (for medical purposes) by purchasing it directly from Health Canada, producing their own plants, or designating someone to produce cannabis for them. In 2015, the Supreme Court of Canada concluded that individuals with a medical need have the right to use and make other cannabis products, and licensed producers were allowed to produce fresh cannabis and cannabis oil.1 Access to medical cannabis through the Cannabis for Medical Purposes Regulations (ACMPR) will continue as is.

Non-Medical

On October 17, 2018 it will be legal to purchase, possess, and use cannabis for non-medical reasons in Canada. The Federal government passed the Cannabis Act, which regulates and controls the production, distribution and the sale of cannabis, and allows adults to legally possess cannabis. The goals of the Cannabis Act include: keeping cannabis out of the hands of youth, profits out of the hand of criminals, and protecting public health and safety by allowing adults access to safe, legal cannabis.2

The Federal government has set strict industry-wide rules and standards for producers who grow and manufacture cannabis. These include restrictions on the types of cannabis products available, packaging and labelling requirements, standardized serving sizes, and prohibiting the use of certain ingredients (e.g. pesticides, chemicals, additives). They have also set standards for production practices, put restrictions on promotional activities, and imposed requirements for tracking cannabis from seed to sale to keep it out of the illegal market.2

The Cannabis Act has several measures that help prevent youth from accessing cannabis. The Act restricts promotion and enticement of products by prohibiting:

  • Products that are appealing to youth;
  • Packaging or labelling products in a way that makes it appealing to youth;
  • Selling through self-service displays or vending machines; and
  • Promoting cannabis (except in narrow circumstances where the promotions would not be visible to young people).2

At this time, cannabis edible products and concentrates will not be permitted to be sold in Canada. The Federal government has stated that the sale of these products will be available approximately one year after the Cannabis Act comes into force.2 On October 17, 2018, individuals wishing to make their own cannabis edibles and other products for personal use will be permitted to do so, provided the use of dangerous solvents is not involved.

Provincial

Medical

The production and sale of medical cannabis is regulated exclusively by the Federal government, and access for medical users will not change once non-medical cannabis is legal.  Places where individuals can use medical cannabis are anticipated to be captured under the Smoke Free Ontario Act, 2017 further details can be found in the Smoke Free Ontario Act, 2017 Report.3

Non-medical

Provinces and territories are responsible for developing, implementing, maintaining and enforcing systems to oversee the distribution and sale of non-medical cannabis; they are also able to add their own safety measures.4 Ontario has chosen to increase the minimum age for possession, consumption, and cultivation of cannabis to people 19 years of age or older, from the federal minimum age of 18 years.

On August 13, 2018 the provincial government announced that beginning on October 17, 2018 adults 19 years and older will be able to purchase cannabis from an online retailer – the Ontario Cannabis Store (OCS). This will be a government entity and a strict age verification system will be used to ensure safe delivery of products. By April 1, 2019, a private retail model will follow. Details of this model are still unknown however the Ontario Government has indicated that an Official Cannabis Retailer Seal will be introduced to identify legitimate retailers. It was also announced that private retailers will be subject to strict rules such as prohibiting the sale of cannabis to anyone under the age of 19, and consultations will take place around other rules such as hours of operation and staff training. The Ontario government has stated that they will give municipalities a one-time window to opt out of permitting physical cannabis retail stores within their boundaries.5

According to the above mentioned announcement, other factors will be included within new cannabis legislation:

  • The use of non-medical cannabis will be restricted to private residences, including the outdoor space of a home, apartment or condo (e.g. porch, backyard, balcony, etc.). It will not be permitted to use cannabis in any public place, workplaces, or motorized vehicles.4
  • Adults (aged 19 years and older) will be able to possess a maximum of 30 grams of dried cannabis in public at any time.
  • Aligning with possession limits, adults will be able to purchase up to 30 grams of dried cannabis at one time.
  • Adults will be able to cultivate up to four cannabis plants per residence (not per person), however, plants cultivated at the home are strictly for personal use and cannot be sold. 4

It is dangerous to drive under the influence of cannabis, as cannabis slows reaction time and increases a person’s likelihood of being in a collision.4 Serious penalties will be imposed on any driver that is found to be impaired by any drug, including cannabis. Once a federally approved roadside device is available, police officers will be authorized to use it to assist in enforcing the law. Novice drivers (drivers who are under 21, have a G1, G2, M1, or M2 license), and commercial drivers will not be allowed to have any cannabis in their system.4,6

The Ontario government has also announced that they will provide $40 million, spread across municipalities over two years to help local governments keep their communities safe. At this point, no additional resources have been given or committed to public health units to address cannabis legalization. It remains unclear what role municipalities and/or public health will have in the legalization process.5

Local context

Cannabis Use

Table 1 provides a snapshot of existing local, provincial and national data on cannabis use. Rates of cannabis use across age groups and regions should not be compared due to differences in survey methodology.

In Canada, males report higher past-year cannabis use than females, however there is no difference between the sexes in terms of age of initiation, which on average is approximately 17 years of age.7 Of those aged 15 and older who have used cannabis in the past three months, 33% reported daily or almost daily use.7

 In a recent national survey, rates of cannabis use in the past three months among those aged 15 years and older were higher in Ontario compared to Canada as a whole (18% and 16%, respectively).8

According to data from the Canadian Community Health Survey, rates of cannabis use in the past year in people 12 years and older in WDG are similar to rates in Ontario as a whole (11.5%* and 11%, respectively).9

Cannabis Use Among Youth

Canadian youth aged 15-24 use cannabis at a rate nearly two-and-a-half times greater than those aged 25 or older (33% and 13%, respectively).8

In 2016, 24% of students at the University of Guelph reported using cannabis in the past 30 days, where the rate among post-secondary students across Canada was 18%.10

In WDG in 2014-15, 1.5% of grade 7 students and 22% of grade 10 students reported past year cannabis use.11 In Ontario in 2017, 2.0% of grade 7 students, 19.9% of grade 10 students, and 37% of grade 12 students reported past year cannabis use.12

In terms of more recent use, 12.1% of students across Ontario in grades 7-12, report cannabis use in the past month and 3.4% report using cannabis daily or almost daily (3-6 times a week).12 The proportion of students who use cannabis daily increases with increasing grade.12 Males and female students are equally likely to use cannabis, however, daily cannabis use is significantly higher among males than females (2.1% and 0.7%, respectively).12

Table 1: Snapshot of most recent data on cannabis use by region and age
Region General population

Youth

WDG 11.5%* (aged 12 and up) used cannabis in the past year.9

24% of students at U of G used cannabis in the past 30 days.10

22% of grade 10 students used cannabis in the past year.11

Ontario

11% of Ontarians (aged 12 and up) used cannabis in the past year.9

18% of Ontarians (aged 15 and up) used cannabis in the past 3 months.8

19.9% of grade 10 students used cannabis in the past year. 37% of grade 12 students used cannabis in the past year.12
Canada 16% of Canadians (aged 15 and up) used cannabis in the past 3 months.8

18% of post-secondary students used cannabis in the past 30 days.10

33% of Canadians aged 15-24 used cannabis in past 3 months.8

*Interpret with caution. High sampling variability.

It is important to note that, according to the second quarter 2018 National Cannabis Survey (NCS), the majority of Canadians (82%) reported that they would be unlikely to try cannabis or to increase their consumption of cannabis with legalization; however among current users, 28% indicated that they would be more likely to increase their use once legal.8

Cannabis Harm

Local data on cannabis related harms in WDG are currently limited. While cannabis-related ED visits are only one part of the picture, they are an important indicator to examine.

In 2016, there were 11 ED visits for cannabis poisoning among residents of WDG.13 Cannabis poisoning ED visits are defined as an adverse effect or reaction to cannabis.

Figure 1 and Figure 2 display cannabis poisoning ED visits from the past five years (2012-2016), and examine demographic differences by sex and age. Throughout 2012-2016, there were a total of 57 cannabis poisoning ED visits among residents of WDG. Of those, 36 were males (63%) and 21 were females (37%). The majority of cannabis poisoning ED visits from 2012-2016 were among residents 15-19 and 20-24.13

Figure 1: Number of cannabis poisoning Emergency Department (ED) visits among residents of Wellington-Dufferin-Guelph by sex from 2012-2016 (5 years)

image with 36 males and 21 females

36 males and 21 females.
Data source: National Ambulatory Care Reporting System (NACRS), accessed 14 Aug 2018.

Figure 2: Number of cannabis poisoning Emergency Department (ED) visits among residents of Wellington-Dufferin-Guelph by age group from 2012-2016 (5 years)

Chart showing age groups for cannabis poisoning

Age Group Number of ED Visits
15-19 14
20-24 15
25-29 5
30-34 5
35-39 5

Number suppressed (less than 5 cases)
Data source: National Ambulatory Care Reporting System (NACRS), accessed 14 Aug 2018

Local Surveillance

In addition to monitoring existing sources of data, local surveillance activities are essential to increasing our understanding of cannabis use and its impacts in WDG.

WDGPH recently conducted an online survey that asked residents in Wellington County, Dufferin County and the City of Guelph ages 16 and up about their knowledge, attitudes, and use of cannabis. Once analyzed, we will have local data on attitudes and knowledge about cannabis products and their health impacts, as well as information from cannabis users on frequency of use, modes of use, sources of cannabis, combined substance use, impaired driving, negative reactions, and cannabis dependency. This data will help to identify ways to reduce cannabis-related harms locally. The survey will be re-administered in the future so that we can continue to monitor the impact of legalization in our local community and adapt programs and services accordingly.

WDGPH is also in the process of exploring accessing data on other cannabis-related indicators to increase our local understanding of the impact of cannabis use in our community, including: ambulance calls, impaired driving, poison control center calls, and data from substance use treatment centers.

Community Mobilization and Education

In the summer of 2017, community partners in Guelph and Wellington identified that preparing for cannabis legalization was a priority for the Wellington Guelph Drug Strategy. A diverse cannabis workgroup was formed, which hosted an expert panel and resource fair for local service providers. During this event, it was identified that the community’s main priority in preparing for cannabis legalization was to ensure that youth had factual knowledge and understanding about cannabis risks and harms.

WDGPH is currently working with youth, community partners, and a video production company to create a youth-driven video campaign and website. The goal of the campaign is to increase knowledge and awareness among youth in WDG around the risks associated with cannabis use and to support informed decision-making. The campaign received funding through a grant opportunity from the Gambling Research Exchange Program (GREO) and is set to launch in early fall 2018.

WDGPH is also working to produce a complementary education campaign to reach a broader audience, including adults and parents. WDGPH’s education campaigns will complement and build on existing campaigns from federal and provincial governments which will focus on health & safety risks and legislation, respectively.

Public Policy

WDGPH has participated in stakeholder consultations, led by the City of Guelph, to prepare for cannabis legalization. WDGPH will continue to work with the City of Guelph and will contact other municipalities in Wellington and Dufferin to offer public health recommendations and support with cannabis policy decisions. Lessons learned from alcohol and tobacco policy will be critical to consider when regulating cannabis at a local level.

Enforcement

Other than police services, it is not yet clear which organizations will be involved with law enforcement related to cannabis. At this time, the WDGPH Health Protection division is not involved with enforcement related to cannabis (medical or non-medical). The medical use of cannabis is anticipated to fall under the Smoke Free Ontario Act, 20173 (which is enforceable by WDGPH), whereas the non-medical use of cannabis is subject to different regulations, and is not enforceable by WDGPH. As public health units currently enforce the Smoke Free Ontario Act, they could be in a unique position to also enforce the prohibition of use of non-medical cannabis in certain locations, provided additional resource allocation. Further clarification of responsibilities for public health surrounding non-medical cannabis is still needed.

Examples from other jurisdictions

In November 2012, Colorado and Washington became the first two US states to legalize personal possession and retail sales of cannabis. Retail sales began January 1, 2014 and July 8, 2014, respectively.14 In a report from the Colorado Department of Public Safety, early findings following the legalization of cannabis are presented.15 The authors remind readers that the results should be interpreted with caution for the following reasons:

  1. Lack of historical data available with which to compare post-legalization data
  2. Decreasing social stigma and legal consequences of cannabis use
    • People may be more comfortable reporting cannabis use on surveys and to health care professionals, thus making rates of use seem higher than they have been in the past, when people may have been hesitant to report use of an illegal substance
  3. Increased numbers of law enforcement officers trained in recognizing drug use
    • Possibly causing an increase in the detection of cannabis use, rather than an actual increase in rates of use

However, with these considerations in mind, a summary of early findings from the Colorado Department of Public Safety report, as well as information from other jurisdictions, are presented below.15

Following the legalization of cannabis in Colorado and Washington, there appear to be:

Increases in:

  • Cannabis-specific risk factors in 10th Grade adolescents16:
    • Low levels of perceived harms,
    • Youth having a more favourable attitude regarding use, and
    • Perceived favourable community attitudes towards use
  • Prevalence of cannabis use in the past 30 days among young adults (18-25 years of age) and adults (26 years of age or older)15
  • Cannabis-related ED visits15
  • Cannabis-related hospitalizations15
  • Unintentional pediatric exposures to cannabis (as measured by admission to children’s hospital and calls to poison control)17
  • Juvenile cannabis-related arrests – increased overall, but ethnic variability was noted,
    • Caucasians experienced a decrease in arrests, while Hispanics and African-Americans experienced increases in arrests15
  • Cannabis-related Driving Under the Influence (DUI) charges15
  • Cannabis-related motor vehicle accident fatalities15
  • Tax revenue15

Decreases in:

  • Adult cannabis-related arrests – overall decrease, but again, ethnic variability was noted, with Caucasian’s experiencing the largest decrease and Hispanics and African-Americans experiencing smaller decreases15
  • Crime rates (property and violent crimes)15
  • Opioid-related deaths18

Stability suggested for:

  • Prevalence of cannabis use in youth:
    • In Colorado, both ever and current cannabis use remain relatively unchanged in high-school youth since legalization19
    • In Washington State, there has been stability in cannabis use in the past 30 days among 10th grade adolescents, even though perceptions of risk have decreased16

Data collection is important over a term long enough to allow for the observation of changes in cannabis use that might occur in response to the change in policy. This is highlighted in a cross-national study, in 38 countries, of the association between adolescent cannabis use and the liberalization of cannabis legislation.20 Results of this study demonstrated a correlation between regular cannabis use (i.e. if adolescent had used cannabis 40 or more times in their lifetime) and cannabis liberalization only after a liberalization policy had been in effect for more than five years.  Duration of policy implementation had no discernable impact on ever use or past-year use of cannabis.

Conclusion

At this point, no additional resources have been given or committed to public health to address cannabis legalization. It is recommended that the Chair, on behalf of the Board of Health, send a letter to the Ontario Government requesting dedicated funding for local public health agencies.

With adequate provincial funding and resources, local public health agencies are uniquely placed to:

  • Gather and share local data on cannabis-related indicators
  • Increase public awareness around the health risks of cannabis use,
  • Build community capacity to facilitate a local response to minimize cannabis-related harms,
  • Assist in the development of public policy related to cannabis, and
  • Enforce non-medical cannabis places of use.

WDGPH supports a comprehensive, collaborative approach to minimizing cannabis-related harms in our community that spans the prevention, harm reduction, enforcement, and treatment pillars of the 4-Pillar Drug Strategy Model.21

Ontario Public Health Standard

Foundational Standards:

Population Health Assessment

Goal: Public health practice responds effectively to current and evolving conditions, and contributes to the public’s health and well-being with programs and services that are informed by the population’s health status, including social determinants of health and health inequities.

Healthy Equity

Goal: Public health practice results in decreased health inequities such that everyone has equal opportunities for optimal health and can attain their full health potential without disadvantage due to social position or other socially determined circumstances.

Effective Public Health Practice

Goal: Public health practice is transparent, responsive to current and emerging evidence, and emphasizes continuous quality improvement.

Program Standards:

Chronic Disease Prevention and Well-Being

Goal: To reduce the burden of chronic diseases of public health importance and improve well-being

Requirement:

  • The board of health shall develop and implement a program of public interventions using a comprehensive health promotion approach that addresses chronic disease risk and protective factors to reduce the burden of illness from chronic disease in the health unit population

Substance Use and Injury Prevention 

Goal: To reduce the burden of preventable injuries and substance use

Requirements:

  • The board of health shall collect and analyze relevant data to monitor trends over time, emerging trends, priorities, and health inequities related to injuries and substance use and report and disseminate the data and information in accordance with the Population Health Assessment and Surveillance Protocol, 2018 (or as current).
  • The board of health shall develop and implement a program of public health interventions using a comprehensive health promotion approach that addresses risk and protective factors to reduce the burden of preventable injuries and substance use in the health unit population. 

WDGPH Strategic Direction(s)
✓ Health Equity: We will provide programs and services that integrate health equity principles to reduce or eliminate health differences between population groups.
✓ Organizational Capacity: We will improve our capacity to effectively deliver public health programs and services.
✓ Service Centered Approach: We are committed to providing excellent service to anyone interacting with WDG Public Health.
✓ Building Healthy Communities: We will work with communities to support the health and well-being of everyone.

Health Equity

Health equity principles are being applied across all WDGPH cannabis projects with the goal of reducing or eliminating differences in cannabis-related harms between population groups.

Young people are a particularly vulnerable group when it comes to cannabis-related harms. Not only are young people (aged 15-24 years) more likely to use cannabis7, they are also more likely to experience cannabis-related harms because their brains are still developing.22 Youth who start to use cannabis regularly at a young age are at a higher risk for developing an addiction, mental health issues, and learning and memory impairments.23,24 Our youth-driven cannabis campaign aims to decrease the burden of cannabis use on this age group by sharing information with youth about the risks of cannabis use and ways to reduce harms, so that youth can make informed decisions.

Other groups at higher risk of experiencing cannabis-related harms include people who have a personal or family history of mental health issues (especially psychosis or substance use disorder) and people who are pregnant. WDGPH will address these risks in public education campaigns set to be released in the fall.

Lastly, continued surveillance will be important to monitor trends in cannabis use and cannabis-related harms across population groups. Communicating this information internally and to the community will allow for the adaptation of programs and services to address priority groups.

References

  1. Government of Canada. Understanding the New Access to Cannabis for Medical Purposes Regulation [Internet]. 2016 Aug [cited: 2018 Aug 10]. Available from: https://www.canada.ca/en/health-canada/services/publications/drugs-health-products/understanding-new-access-to-cannabis-for-medical-purposes-regulations.html
  2. Government of Canada, Department of Justice. Cannabis Legalization and Regulation [Internet]. 2018 Aug 09 [cited: 2018 Aug 10]. Available from: http://www.justice.gc.ca/eng/cj-jp/cannabis/
  3. Wellington-Dufferin-Guelph Board of Health. BOH report - Smoke Free Ontario Act, 2017. 5 Sept 2018 [cited: 2018 Aug 15].
  4. Ontario. Cannabis Legalization [Internet]. 2018 Jul 31 [cited: 2018 Aug 10]. Available from: https://www.ontario.ca/page/cannabis-legalization
  5. Ministry of Finance. News Release: Ontario Announces Cannabis Retail Model [Internet]. 2018 Aug 13 [cited 2018 Aug 14]. Available from: https://news.ontario.ca/mof/en/2018/08/ontario-announces-cannabis-retail-model.html
  6. Highway Traffic Act, R.S.O. 1990, c. H. 8. Available from: https://www.ontario.ca/laws/statute/90h08?search=highway+traffic+act
  7. Government of Canada. Canadian Tobacco Alcohol and Drugs (CTADS): 2015 summary [Internet]. 2017 Jun 27 [cited 2018 Aug 13]. Available from: https://www.canada.ca/en/health-canada/services/canadian-tobacco-alcohol-drugs-survey/2015-summary.html
  8. Government of Canada, Statistics Canada. National Cannabis Survey, second quarter 2018 [Internet]. 2018 Aug 09 [cited 2018 Aug 13]. Available from: https://www150.statcan.gc.ca/n1/daily-quotidien/180809/dq180809a-eng.htm
  9. Canadian Community Health Survey 2015, accessed 13Aug2018.
  10. University of Guelph. National College Health Assessment 2016 [Internet]. 2016 [cited 2018 Aug 13]. Available from: https://www.canada.ca/en/health-canada/services/canadian-tobacco-alcohol-drugs-survey/2015-summary.html
  11. WDG Report Card Coalition. WDG Youth Survey, 2011-12 and 2014-15 [Internet]. 2016 Jul 26 [cited 2018 Aug 13]. Available from: http://www.wdgreportcard.com/en/data-portal/illicit-drug-use.aspx
  12. Boak A, Hamilton HA, Adlaf EM, Mann RE. Drug use among Ontario students, 1977-2017: Detailed findings from the Ontario Student Drug Use and Health Survey (OSDUHS). Centre for Addiction and Mental Health [Internet]. 2017 [cited 2018 Aug 13]. Available from: https://www.camh.ca/-/media/files/pdf—osduhs/drug-use-among-ontario-students-1977-2017—detailed-findings-from-the-osduhs.pdf?la=en&hash=2B434CDAAD485834497E3B43F2264BDEB255F29F
  13. National Ambulatory Care Reporting System (NACRS), accessed 14Aug2018
  14. Canadian Centre on Substance Abuse.  Cannabis regulation: Lessons learned in Colorado and Washington State [Internet]. November 2015 [cited 2018 Aug 15]. Available from: http://www.ccsa.ca/Resource%20Library/CCSA-Cannabis-Regulation-Lessons-Learned-Report-2015-en.pdf
  15. Colorado Department of Public Safety. Marijuana legalization in Colorado: Early findings. A report pursuant to Senate Bill 13-283 [Internet]. March 2016 [cited 2018 Aug 15].  Available from: https://cdpsdocs.state.co.us/ors/docs/reports/2016-SB13-283-Rpt.pdf
  16. Fleming CB, Guttmannova K, Cambron C, Rhew IC, Oesterle S. Examination of the divergence in trends for adolescent marijuana use and marijuana-specific risk factors in Washington State.  J Adolesc Health [Internet]. 2016 [cited 2018 Aug 15]; 59(3): 269-275. Available from: https://www.sciencedirect.com/science/article/pii/S1054139X16300647
  17. Wang GS, Le Lait MC, Deakyne SJ, Bronstein AC, Bajaj L, Roosevelt G. Unintentional pediatric exposures to marijuana in Colorado, 2009-2015. JAMA Pediatr. 2016; 170(9): pp. e160971.
  18. Livingston MD, Barnett TE, Delcher C, Wagenaar AC.  Recreational cannabis legalization and opioid-related deaths in Colorado, 2000-2015. Am J Public Health. 2017;107:1827-1829.
  19. Colorado Department of Public Health and Environment. Data brief: Colorado youth marijuana use 2017 [Internet]. 2017 [cited 2018 Aug 16]. Available from: https://drive.google.com/file/d/1M3XdmqznZDl2y6D7Hz6iDGwTFTHSGrtP/view
  20. Shi Y, Lenzi M, An R. Cannabis liberalization and adolescent cannabis use: A cross-national study in 38 countries. PLoS ONE [Internet]. 2015 [cited 2018 Aug 15];10 (11). Available from: https://www.researchgate.net/publication/284720668_Cannabis_Liberalization_and_Adolescent_Cannabis_Use_A_Cross-National_Study_in_38_Countries
  21. Wellington Guelph Drug Strategy. 4 pillar drug strategies [Internet]. 2011 [cited 2018 Aug 15]. Available from: http://wgdrugstrategy.ca/get-informed/4-pillar-drug-strategies/
  22. Canadian Centre on Substance Abuse. Substance abuse in Canada: The effects of cannabis use during adolescence [Internet]. 2015 [cited 2018 Aug 13]. Available from: http://www.ccsa.ca/Resource%20Library/CCSA-Effects-of-Cannabis-Use-during-Adolescence-Report-2015-en.pdf
  23. Government of Canada. Health Effects of Cannabis [Internet]. [cited 2018 Aug 13]. Available from: https://www.canada.ca/content/dam/hc-sc/documents/services/campaigns/27-16-1808-Factsheet-Health-Effects-eng-web.pdf
  24. Canadian Centre on Substance Abuse. Clearing the smoke on Cannabis. Chronic use and cognitive functioning and mental health: an update [Internet]. 2016 [cited 2018 Aug 13]. Available from: http://www.ccsa.ca/Resource%20Library/CCSA-Effects-of-Cannabis-Use-during-Adolescence-Report-2015-en.pdf