A new study from the Yale School of Public Health published in the journal Addiction found that higher rates of e-cigarette and marijuana use in US states did not result in more e-cigarette or vaping-related lung injuries (known as EVALI).
The study estimated the relationship between states' total reported EVALI cases per capita as of January 2020 and pre-outbreak rates of adult vaping and marijuana use. Results show that higher rates of vaping and marijuana use are actually associated with fewer EVALI cases per capita.
Assistant professor Abigail Friedman, the study's author, said, “If e-cigarette or marijuana use per se drove this outbreak, areas with more engagement in those behaviors should show a higher EVALI prevalence. This study finds the opposite result. Alongside geographic clusters of high EVALI prevalence states, these findings are more consistent with locally available e-liquids or additives driving the EVALI outbreak than a widely used, nationally-available product."
Friedman also pointed out that a negative relationship between EVALI prevalence and rates of pre-outbreak vaping and marijuana use suggests that well-established markets may have crowded-out use of riskier, informally sourced e-liquids.
The Centers for Disease Control and Prevention (CDC) began a cross-state investigation into vaping-related lung injuries in August 2019. In February 2020, CDC concluded its national updates, and officially classified vitamin E acetate, an additive long linked to EVALI, and most common in THC e-liquids that are informally-sourced, i.e. purchased off the street or home-mixed, as "a primary cause of EVALI.
"The EVALI outbreak led to many state and federal legislation to restrict sales of nicotine e-cigarettes, including a temporary ban on all e-cigarette sales in Massachusetts in late-2019 and bans on flavored e-cigarette sales in several states and localities. However, if the goal was to reduce EVALI risks, the study suggests that those policies may have targeted the wrong behavior.