States With Legal Recreational Cannabis Have Fewer Vaping Lung Injuries, Study Finds
Cases of e-cigarette or vaping-associated lung injury (EVALI) are less common in states with access to legal recreational cannabis, suggests new analysis published in .
As of February 18, 2020, have been recorded by the US Centers for Disease Control and Prevention (CDC), spawning all 50 states, the District of Columbia, and two US territories (Puerto Rico and the US Virgin Islands).
The EVALI outbreak has been strongly linked to vitamin E acetate, a cutting agent known to be commonly used in . The discovery of this link prompted the US Food and Drug Administration (FDA) to against using all cannabis vape products, whether sourced from legal dispensaries or not.
Now that black-market cannabis vape products are the suspected cause of the recent rise in EVALI cases, this new analysis sought to investigate whether EVALI case rates might be lower in states with legal recreational cannabis – where consumers would have easier access to legal vape products, which are required to pass quality and safety tests set by local regulators.
Recreational states show significantly lower EVALI case rates
The authors conducted a cross-sectional analysis at the state level (and Washington DC) on the number of EVALI cases reported by each state to the CDC in 2019. Data on state populations were taken from the Surveillance, Epidemiology, and End Results database and estimates of state e-cigarette usage from the Behavioral Risk Factor Surveillance System, both data sets from 2017.
For the purposes of this analysis, the EVALI case rate for each state was taken as the midpoint of the CDC-reported range of cases per million population. States were also classified as either a recreational, medical, or prohibition state, based on the laws and operational dispensaries in place before January 1, 2019.
The researchers found that the average recreational cannabis state had 1.7 EVALI cases per million people. In contrast, the EVALI case rate in medical cannabis states was calculated to be 8.8 cases per million, and in prohibition states 8.1 cases per million, though the difference in EVALI case rate between medical and prohibition states wasn’t deemed statistically significant.
“It appears states that have legal access to marijuana have lower rates of EVALI cases, which is consistent with the hypothesis that people have demand for marijuana products, and in states where they don't have access to them in this regulatory fashion, they end up purchasing them elsewhere,” said study author Alex Hollingsworth, to .
The researchers also examined the prevalence of e-cigarette and vape use in each state, to ensure that this wouldn’t confound any association between EVALI and state cannabis laws. They found average e-cigarette use to be quantitatively similar across all three categories of states. No statistically significant trends were seen. There was also no association seen between the prevalence of e-cigarette use and EVALI case rates.
What’s behind this trend?
The most obvious inference from the study results is that the existence of legal cannabis markets can protect patients from EVALI by ensuring access to regulated products, though the study authors are careful not to call this conclusion definitive.
“The reason for this association is not yet clear,” they wrote. “It is possible that in recreational states, people tend to purchase marijuana products at legal dispensaries, which may be less likely to sell the contaminated products that are thought to cause EVALI. In addition, the data are not informative about the potentially complicated interactions between safety regulations, bans, and prohibitions for goods such as marijuana, tobacco, and vaping products. Future research should examine these issues in more detail.”
In an to this study, Scott K. Aberegg and colleagues from the University of Utah School of Medicine drew comparisons between cannabis prohibition and the prohibition of alcohol in the 1920s. Then, in the absence of legally available alcohol, many Americans turned to bootleg drinks, which were fortified with methanol, benzene, and other harmful substances. This is similar to the pattern seen with cannabis use today; cannabis users in prohibition states are using illicit products that may contain unsafe chemicals.
“The history of prohibition thus serves as a cautionary tale about unintended and unforeseen consequences of legislation regulating substances that affect public health,” the researchers wrote.
However, the study's authors also note that while recreational cannabis legalization does appear to have had local protective effects in the case of EVALI, there could still be other collateral effects worth considering. For example, legal cannabis products could be trafficked into prohibition states where they are then cut with vitamin E acetate in order to dilute and ‘stretch out’ the products to be sold on the black market for a greater profit.
As a whole, the authors of the latest study said its findings demonstrate "the complex realities of social movements and resulting legislation that may have unforeseen and unforeseeable public health consequences, for better and for worse, that are recognized only in retrospect,” they wrote. “If history teaches us anything, it is to be careful.”