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Fewer EVALI Cases in States with Recreational Marijuana

MedicalResearch.com Interview with:

Alex Hollingsworth PhD Assistant Professor O'Neill School of Public and Environmental Affairs Indiana University

Dr. Hollingsworth

Alex Hollingsworth PhD
Assistant Professor
O’Neill School of Public and Environmental Affairs
Indiana University

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: I’ve been working with Coady Wing and Ashley Bradford on a few different studies of the effects of recreational marijuana laws on drug and alcohol use.

Soon after EVALI became a major issue, the prevailing theory from the CDC and others was that EVALI was caused by the use of vitamin E acetate in illegal THC vaping products.

Our group read about this and we thought about some of the things that often happen in black markets for illegal drugs. For instance, during the alcohol prohibition era, bootleg alcohol producers often made and sold alcohol products that were not that safe to drink. In more recent years, there are cases where black market sellers of illegal drugs like heroin try to increase profit margins by adding other substances, which can be harmful.

We thought that maybe something like that could be happening in EVALI. Perhaps people in states where recreational marijuana is legal tended to purchase marijuana products from the legal market and the legal market was not selling any marijuana vaping products that included vitamin E acetate.

MedicalResearch.com: What should readers take away from your report?

Response: Our study is very simple and it’s important not to read into the results too much. We computed the number of EVALI cases per 1 million population in each state.

And then we compared the average EVALI case rate in three groups of states:
(i) recreational marijuana states,
(ii) medical marijuana states,
(iii) prohibition states.

We found that in the recreational marijuana states, there were only about 1.7 cases per million people. The EVALI rates were much higher in the other groups of states: 8.1 EVALI cases/million in prohibition states and 8.8 EVALI cases/million in medical states. In other words, EVALI cases were concentrated in states where recreational marijuana is illegal. The size of the difference was surprising to me. Essentially, recreational marijuana states have about 6.4 to 7.1 fewer EVALI cases per million than the other states. That’s a big gap.  

MedicalResearch.com: What recommendations do you have for future research as a result of this work?

Response: Ideally more research would be done on the purchasing/consumption behavior of THC products for  those who live in states with and without legal cannabis markets. Importantly our study does not evaluate if recreational marijuana or if e-cigarettes/vaping devices are dangerous. Assessing the potential harms and benefits (e.g., e-cigarettes potentially decreasing traditional cigarette smoking) for each of these is an important area needed more research.  

MedicalResearch.com: Is there anything else you would like to add? 

Response: Our study has a number of limitations, it is important not to read into our results as causal. We did not examine an experiment or use a quasi-experimental setting to assess causality. However, the results are suggestive that access to legal markets for marijuana mitigated, in this one instance, the use of contaminated illegal products. This is not to say that illegal products are always unsafe and legal products are always safe. The results are also suggestive that attempts to curb EVALI by banning legal e-cigarette vaping devices will likely be unsuccessful.


Wing C, Bradford AC, Carroll AE, Hollingsworth A. Association of State Marijuana Legalization Policies for Medical and Recreational Use With Vaping-Associated Lung Disease. JAMA Netw Open. 2020;3(4):e202187. doi:10.1001/jamanetworkopen.2020.2187

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Last Updated on April 22, 2020 by Marie Benz MD FAAD