Research PaperMedical marijuana laws and workplace fatalities in the United States
Introduction
Although marijuana remains illegal under federal law, 29 states and the District of Columbia have passed laws legalizing its use for medicinal purposes (State Medical Marijuana Laws, 2017). Medical marijuana laws (hereafter MMLs) remove state-level penalties for using and possessing marijuana for medical purposes. Patients are required to obtain approval or certification from a physician, and physicians who recommend marijuana to their patients are immune from criminal prosecution.
Increasingly, concerns are being raised over the potential impact of MMLs on workplace safety (Goldsmith et al., 2015; Parnes, Bravo, Conner, & Pearson, 2018; Phillips et al., 2015; Schwartz, 2017). As a backdrop to these concerns, there are important legal issues surrounding workplace safety and the use of medical marijuana that remain unresolved. For instance, in many states it is unclear whether employers can impose sanctions on registered medical marijuana patients who test positive for tetrahydrocannabinol (the psychoactive component in marijuana), or whether insurance companies can claim marijuana as the cause of injury or death in the workplace (Deitchler, 2015; Hickox, 2012; Olafson, 2016).
There is strong evidence that legalizing medical marijuana leads to a decrease in the price of marijuana and an increase in its consumption, presumably due to diversion from the medical to the recreational market (Anderson, Hansen, & Rees, 2013; Chu, 2014, 2015). However, the association between legalization and workplace safety could, in theory, be negative or positive. On the one hand, extensive research has demonstrated that there are important short-term effects of marijuana use on psychomotor performance and cognition that could lead to more on-the-job accidents, including impairments in memory function, information processing, hand-eye coordination, and reaction times (Hall, 2009; Hartman & Huestis, 2013; Marijuana, 2017; Ramaekers, Berghaus, van Laar, & Drummer, 2004). On the other hand, previous studies have found that the legalization of medical marijuana leads to substantial reductions in the consumption of alcohol, opioids and other substances, (Anderson et al., 2013; Bachhuber, Saloner, Cunningham, & Barry, 2014; Bradford & Bradford, 2016; Reiman, 2009; Sabia, Swigert, & Young, 2017), which could lead to safer workplaces and fewer accidents.
Drawing on data at the state-year level collected by the Bureau of Labor Statistics for the period 1992–2015, the relationship between legalizing medical marijuana and workplace fatalities was examined. Multivariate Poisson regression analysis was used to adjust for demographics, income, the unemployment rate, legalization of recreational marijuana, decriminalization of marijuana, state fixed effects, and year fixed effects. No previously published study has examined the relationship between MMLs and workplace fatalities.
Section snippets
Methods
Panel data on workplace fatalities at the state-year level came from Census of Fatal Occupational Injuries (CFOI). These data are produced by the Occupational Safety and Health Statistics (OSHS) program, which is administered by the Bureau of Labor Statistics (BLS). The CFOI provides counts of all fatal work injuries occurring in the U.S. during each calendar year. The OSHS program uses diverse state, federal, and independent data sources to identify, verify, and describe fatal work injuries,
Results
The association between legalizing medical marijuana and total workplace fatalities, although negative, was not statistically significant at conventional levels (Table 3). By contrast, legalizing medical marijuana was associated with a 19.5% reduction in the expected number of workplace fatalities among workers aged 25–44 (IRR, 0.805; 95% CI, .662–.979) after adjusting for the covariates listed in Table 2, state fixed effects, and year fixed effects. This negative association was robust to
Discussion
MMLs protect patients from criminal prosecution for smoking marijuana and for consuming it in oils, pills, and edibles. However, the use of medical marijuana in the workplace is generally not protected. Several states (e.g., Colorado, Michigan, Oregon, Washington) have ruled that employers may discipline employees or terminate their employment following a positive drug test because MMLs are not intended to address employment issues (Deitchler, 2015; Hickox, 2012). Although some MMLs explicitly
Conclusion
Although 29 states and the District of Columbia have passed laws legalizing marijuana for medicinal use, there is a dearth of evidence on the relationship between medical marijuana and workplace safety. The current study is the first to explore the effects of medical marijuana laws on workplace fatalities. Our results suggest that legalizing medical marijuana leads to a reduction in workplace fatalities among workers aged 25–44. This reduction may be the result of workers substituting marijuana
Conflict of interest disclosures
None reported.
Funding/Support
Partial support for this research came from a Eunice Kennedy Shriver National Institute of Child Health and Human Development research infrastructure grant, R24 HD042828 to the Center for Studies in Demography and Ecology at the University of Washington.
Role of the Funder/Sponsor
The funder had no role in the design and conduct of the study; collection, management, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.
Author contributions
Drs. Anderson and Rees had full access to the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.
Study concept and design: Anderson, Rees, Tekin.
Acquisition, analysis, or interpretation of data: Anderson, Rees.
Drafting of the manuscript: Anderson, Rees, Tekin.
Critical revision of the manuscript for important intellectual content: Anderson, Rees, Tekin.
Statistical analysis: Anderson.
Obtained funding: Anderson.
Administrative, technical,
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