A new study conducted by the U.S. Centers for Disease Control and Prevention indicates that use of marijuana in e-cigarettes at least once varies by racial group among U.S. youth, highlighting the importance of equitable implementation of health education and targeted intervention strategies against vaping as it becomes increasingly common.

The associated paper, published April 26 in JAMA Pediatrics, notes that from 2017 to 2020, there were noticeable increases in U.S. students of all racial and ethnic groups reporting they had vaped e-cigarette-based marijuana. Hispanic youth had the highest increase, at more than 11 percentage points. 

Non-Hispanic black youth had nearly a 9-percentage-point increase, non-Hispanic white youth had about a 7-percentage-point increase, and other non-Hispanic races had about a 6-percentage-point increase.

Though non-Hispanic racial groups showed a lower change in behavior over the years, their total use of marijuana in e-cigarettes was still high. Of all 13,719 students surveyed in 2020, 19.5% reported having ever used marijuana in an e-cigarette. Over 19% of non-Hispanic black youth and over 18% of non-Hispanic white youth surveyed affirmed their use. However, use by Hispanic youth was still greater, as about 25% affirmed use.

Study author Christina Vaughan Watson, a health scientist in the CDC's Office on Smoking and Health, told The Academic Times that as states increasingly legalize adult marijuana sales, variables such as ease of access and social acceptance of the drug among youth will likely continue to grow. That makes studies on the topic more timely than ever, particularly on a population scale. 

A recent paper speculated that frequent use of marijuana leads to a drop in IQ, while a separate work suggested that legalizing the drug doesn't, in fact, lead to broadened usage. Despite the latter, Watson urges preparation for possible changes in marijuana use among youth.

"Understanding demographic variations among those who are using marijuana in e-cigarettes can help inform evidenced-based interventions that may resonate with specific populations," Watson said. "Assessing change in use-behaviors over time is an important component of public-health surveillance."

For this work, however, the initial motivation was to better understand the overall prevalence of marijuana use via e-cigarettes among youth. It was of particular interest, Watson said, given the context of the 2019 outbreak of e-cigarette or vaping product use-associated lung injury, or EVALI, an emergent form of lung disease caused by vaping. 

In 2019, there were numerous reports of young people suddenly developing lung disease for unknown reasons. Eventually, the CDC realized that the common factor was e-cigarette usage, and the first case of EVALI was diagnosed.

According to the American Lung Association, 96% of all EVALI patients were hospitalized, including some who died. 

The active ingredient of marijuana is tetrahydrocannabinol, or THC. Watson emphasizes that in addition to the risks that come with vaping in general, chemical concentrations of THC and nicotine are shifting along with the rampant rise of e-cigarette use. As of 2020, the CDC study states, one in five U.S. middle and high schoolers reported ever using marijuana in an e-cigarette, adding up to more than 5 million students. 

That has unknown consequences for addiction, meaning it could potentially increase one's need to vape and, in turn, one's likelihood of developing lung disease.

"The nicotine concentration in nicotine e-cigarette products has increased nearly 80% since 2013," Watson said, adding that "butane hash oils, THC concentrates and waxes that can be vaped can have higher THC potency than dried marijuana plant material that is typically used for smoking."

Because of EVALI's little-studied consequences and the risks posed by marijuana in e-cigarettes, the team aims to understand how the threats will carry through population groups over time.

"Monitoring the prevalence of modes of marijuana, tobacco and other substance use at national and state levels could inform policies, prevention education, communication and cessation tools," Watson explained.

Results were collected from the National Youth Tobacco Survey as it was given in 2017, 2018 and 2020; 2019 was omitted because the survey was not offered that year. Though the team tested the validity of the survey by conducting standard procedures and focusing on question wording, Watson acknowledges that some limitations were inevitable. 

"We recognize that because we are asking about an illegal activity, some respondents could be less forthcoming about answering some of these questions," she said. 

The study notes other limitations, including the mode of survey administration, which was paper-based in 2017 but electronic in 2018 and 2020. The questions also didn't separate experimentation from a more substantive vaping session or consider subsequent use. The study also notes that the term "electronic cigarette" may not have resonated with some marijuana users.

Watson also mentioned that while future research is needed to assess the origin of such differences among racial groups in marijuana use with e-cigarettes, the new study suggests that prevention methods should be adjusted according to population density of a particular race.

"This research may help provide insight into the design and evaluation of prevention and cessation interventions, particularly with respect to the targeting, tailoring and equitable implementation of such interventions," she said.

The study, "Racial and ethnic differences in marijuana use in e-cigarettes among US youth in 2017, 2018, and 2020," published April 26 in JAMA Pediatrics, was authored by Christina V. Watson, Samantha Puvanesarajah and Katrina F. Trivers, U.S. Centers for Disease Control and Prevention.