When Washington state legalized cannabis for adult use in 2012, concerns were raised about potential public health consequences. Retail cannabis stores began opening in 2014, starting with 31 stores and expanding to 447 by 2020. A new study examined whether the availability of these stores was associated with changes in various types of deaths across Washington’s 39 counties.
The Study
Researchers analyzed death records from 2009 through 2020, examining five types of mortality: suicide, motor vehicle accidents, opioid poisoning, homicide, and accidental poisonings. They used statistical models to examine the relationship between the number of cannabis retail stores per 10,000 population in each county and death rates for each category.
During the 12-year study period, Washington state experienced 12,933 deaths from suicide (77% men), 6,761 deaths from motor vehicle accidents (71% men), 8,858 deaths from opioid poisoning (62% men), 2,408 homicides (73% men), and 11,873 deaths from accidental poisonings (64% men).
Key Findings
The analysis revealed that counties with more cannabis retail stores per capita had lower rates of certain types of deaths. Specifically, greater store availability was associated with reduced accidental poisoning deaths and reduced opioid-related deaths. For both categories, counties with more stores per 10,000 residents showed mortality rates that were about 17% lower than counties with fewer stores.
Importantly, the researchers found no significant relationship between cannabis store availability and deaths from motor vehicle accidents, homicide, or suicide. This suggests that the expansion of cannabis retail stores was not associated with increases in these types of deaths.
What This Means
The findings do not support concerns that increased availability of legal cannabis through retail stores leads to harmful effects on mortality. The observed associations with reduced accidental poisoning and opioid deaths suggest possible benefits, though the study design cannot prove that cannabis stores directly caused these reductions.
The results add to a growing body of research examining public health impacts of cannabis legalization. While prior studies have shown mixed findings when looking at state-level data, this study’s focus on county-level variation within Washington state provides a more detailed picture of how cannabis retail availability relates to different types of mortality.
The study covered the period from 2009 to 2020, allowing researchers to compare mortality rates before and after legalization and retail store expansion, while accounting for differences between counties over time.
Kerr, W. C., & Ye, Y. (2025). Cannabis retail store density and county-level mortality from injury in the state of Washington from 2009-2020. The American journal of drug and alcohol abuse, 51(1), 107–115. https://doi.org/10.1080/00952990.2024.2436524
