Vaping has been known for its association with respiratory disease and nicotine addiction. Now, a new study, building upon previous evidence, has found that among teens, vaping often may spike the risk of exposure to lead and uranium — potentially harming brain and organ development in young people.
“This study analyzed a nationally representative sample of U.S. adolescent e-cigarette use to examine whether urine metal levels (i.e., cadmium, lead and uranium) differed by vaping frequency and flavor types,” said Dr. Hongying Daisy Dai, senior author of the study published Monday in the journal Tobacco Control, via email.
Vaping has slightly declined among teens. The use of e-cigarettes among high schoolers decreased from 14.1% to 10% from 2022 to 2023, the 2023 National Youth Tobacco Survey found. But for this group, the behavior has remained a public health concern and the most popular form of consuming tobacco (in the form of nicotine) since 2014, Dai said.
As of December 2023, only 23 tobacco-flavored e-cigarette products are authorized by the US Food and Drug Administration for sale in the United States, after the agency effectively banned all flavors of cartridge-based vape pens except menthol and tobacco to prevent young people from vaping. The ban, however, does not include disposable e-cigarettes or their respective e-liquids, which come in a variety of flavors.
Dai and coauthors found that among teens who vaped intermittently — for six to 19 days total out of the past 30 days — urine lead levels were 40% higher compared with occasional vapers, defined as one to five days out of the past month. For those who vaped frequently — 20 days or more — levels were 30% higher. And e-cigarette users who preferred sweet flavors had higher levels of uranium in their urine than those who favored menthol or mint flavor, said Dai, a professor in the department of biostatistics at University of Nebraska Medical Center.
Nearly 90% of youth who vape use flavored e-cigarettes, according to the National Youth Tobacco Survey.
Given that e-cigarette aerosol is known to contain various potentially harmful compounds including metals, Dai wasn’t surprised by the findings, she said.
However, chronic exposure to metals, “even at low levels, can lead to detrimental health impacts, affecting cardiovascular, renal, cognitive and psychiatric functions,” she added.
The study was conducted at one point in time, so the authors couldn’t control for chronic or long-term exposure. But “no form of tobacco consumption is safe for young individuals,” Dai said. “Parents should be aware of the harmfulness of e-cigarette use and advise their children to quit vaping.”
The study’s findings are based on the responses and biospecimen samples of 200 teens involved in the Population Assessment of Tobacco and Health, or PATH, Youth Study from December 2018 to November 2019.
Vaping and health harms
Expert opinions on the findings are mixed.
“This is a well-conducted study underscoring the need to carefully monitor exposure in e-cigarette users and highlights the fact that e-cigarettes are not risk free,” said Dr. Lion Shahab, professor of health psychology at University College London and codirector of the UCL Tobacco and Alcohol Research Group, in a news release.
“However, these findings also need to be seen in context,” Shahab, who wasn’t involved in the study, added. “Uranium specifically has many different important sources of exposure (including food, water connected to geographic location), which were not controlled for in this analysis. Further, previous work has not found differences in uranium exposure between non-users and users of e-cigarettes nor detected uranium in e-cigarette aerosol, suggesting this finding may be explained by other factors.”
Lead, however, has been detected in e-cigarette aerosol in previous research, Shahab added. Yet the urine levels reported in this study, even in frequent vapers, are below or similar to those found in the general population and in adults who don’t vape.
“Nonetheless, it is important to note that no level of lead exposure is safe,” Shahab said.
The authors acknowledged that their study is observational, meaning it didn’t find a causal relationship between vaping and toxic metal levels.
But the authors think the metals’ presence in participants’ urine may be related to how e-cigarettes work.
“E-cigarettes are battery-powered devices that generate aerosols by heating a liquid solution with a metal coil,” Dai said. “This heating process might result in the release of metal particles into the liquid inhaled by e-cigarette users.”
Teens choose sweet flavors over others since the former can suppress the harsh effects of nicotine, enhancing its reward effects, Dai said. But knowing why this preference led to higher uranium exposure requires more research. A 2021 study, however, did find ethyl maltol, an artificial sweetener used in some vaping liquids that has the flavor of cotton candy, can help transport heavy metals to cells and, when in the presence of copper, could cause cells lining the lungs to die.
And “given that heavy metal exposure is mostly driven by the type of device used,” Shahab said, “future studies should investigate whether there are any meaningful differences between different e-cigarette types to inform regulators, e.g., to curtail use of devices that expose users to more heavy metals.”
If you want to stop vaping, or if you’re a parent or guardian who wants to help your teen stop vaping, there are steps you can take today.
Knowing one’s personal reasons for quitting may help you make choices conducive to your goal more than simply knowing about the health harms can. Setting a quit date can aid you in mentally preparing for any challenges. Working with a therapist can help you identify what your triggers and challenges might be, and you can even make a personal quit plan based on your daily life.