Vaping-Related Lung Injury: What Drove the Outbreak?

Higher rates of e-cigarette and cannabis use were not associated with greater incidence of e-cigarette or vaping-related lung injuries (EVALI) during the 2019 outbreak of the condition, according to the results of a recent study.1

In order to examine whether use of cannabis and e-cigarettes alone drove the outbreak, rather than a particular additive to the products, the researchers examined EVALI data from state health departments detailing cases among 12-64-year-old patients as of January 2020.

The average state prevalence of EVALI was 1.4 cases per 100,000 individuals within the included age group, with particularly high prevalence observed among northern-Midwest states. Overall, the researchers observed a negative association between rates of EVALI and vaping and past-month cannabis use.

“If e-cigarette or marijuana use per se drove this outbreak, areas with more engagement in those behaviors should show a higher EVALI prevalence,” said study author Abigail Friedman, PhD, in an accompanying press release. “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.”2

—Michael Potts


  1. Friedman AS. Association of vaping‐related lung injuries with rates of e‐cigarette and cannabis use across US states. Published online August 25, 2020. Addiction. doi:10.1111/add.15235
  2. Rates of e-cigarette and marijuana use not associated with larger outbreaks of vaping-related lung injuries, YSPH study finds. News release. Yale School of Public Health. August 25, 2020.