Cannabis legalization in San Francisco: A health impact assessment

Kudos to Cyndy Comerford and Max Gara from the San Francisco Department of Public Health, Health Impact Assessment (HIA) Program! Also, special acknowledgments to Michelle Kirian and Erik Dove for their important contributions.

Excerpt from the Executive Summary

On November 8, 2016, California voters passed Proposition 64, the “Adult Use of Marijuana Act.” This proposition made it legal for individuals age 21 and older to use, possess, and make non-medical cannabis available for retail sale.1 While the legalization of cannabis may have direct benefits to communities, from the regulation and taxation of cannabis sales to the substance’s continued de-criminalization, the public health impacts of legalization are lessor known. The legalization of adult use cannabis is relatively new in the United States and therefore there is limited and con icting evidence on its public health implications. This report assesses the most up-to-date information and draws together evidence from multiple sources to better understand the potential health impacts associated with cannabis legalization in San Francisco. The report aims to help inform discussions on the legalization process and provide a health lens to more fully understand its implications. This report uses a health impact assessment (HIA) framework to evaluate any potential negative heath impacts or harms to communities from legalization and strategies for their preventions and/or mitigation. The following goals were used to provide an overall structure to guide the project:

  1. Prevent youth access and exposure to cannabis
  2. Minimize potential harms to communities from cannabis use
  3. Prevent the renormalization of tobacco product use and reverse of declining use rates
  4. Ensure perceptions of cannabis recognize risks associated with use

Based on these goals, the following research question was formulated for the analysis: What are the health impacts of adult use cannabis retailers on San Francisco communities? More specifically, the report wanted to evaluate: How does the density of and proximity to adult use cannabis retailers impact youth exposure and neighborhood quality of life?2 And how does allowing onsite consumption of adult use cannabis impact youth exposure and neighborhood quality of life? For the latter question, evidence in the literature was sparse and key informant feedback was somewhat limited, thus it was not a focal point of the report.

This assessment draws together evidence from multiple different data sources to develop a holistic understanding of the health impacts associated with cannabis legalization in order to answer the aforementioned research questions. Data sources included epidemiological data, scientific literature, expert and key informant opinions collected from interviews and focus groups, and diverse quantitative indicators associated with health and the neighborhood environment. These data sources were analyzed for population wide trends and strati ed to examine potential disproportionate impacts of different sub-populations (e.g. by age, race/ethnicity) in following with the goals of the report. Since adult use cannabis in the United States is an emerging industry and there was limited evidence about specialized cannabis services such as onsite consumption.


  1. Take a measured approach to regulating adult-use cannabis.
  2. Implement a robust public educational campaign.
  3. Integrate cannabis into youth prevention programming.
  4. Address potential disproportionate impacts to communities.
  5. Strong regulation of cannabis edibles.
  6. Develop advertising standards to protect youth and work to avoid creating social norms.

To read full report click here.


  1. The proposition allows the possession, transportation, purchasing and consuming up to one ounce of adult use cannabis and eight grams of adult use cannabis concentrates, and allows personal cultivation for up to six plants in a private residence. ↩︎

  2. Neighborhood quality of life refers to issues such as crime, nuisances (e.g. noise, double parking, etc.), and traffic related injuries (e.g. pedestrian, bike, and vehicle-related injuries). ↩︎

Tomás Aragón
Tomás Aragón
Health Officer, City & County of San Francisco; Director, Population Health Division

I exercise legal authority to protect and promote equity and health, and I direct core public health services.

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