Secondhand vape exposure detectable in children's saliva, breath

Credit: Unsplash / Rubén Bagüés

Saliva, among other less invasive biomatrices, may be used to reliably detect exposure to and downstream metabolites of secondhand electronic cigarette vapor, according to new research.

New research presented in a poster at the NAPNAP 2024 National Conference on Pediatric Health Care in Denver, CO this week showed that various harmful, chemical-based metabolites indicating exposure to secondhand e-cigarette vapors are detectable in children—not only via blood tests, but from analysis of their saliva and exhaled breath condensate. The findings contribute to the understood detectability of vaping exposure among susceptible populations like children, and additionally put onus on their adults to decrease nicotine use and/or minimize the risk of secondhand exposure.

Investigators led by Jeannie Rodriguez, PhD, CPNP-PC, of the Emory University Nell Hodgson Woodruff School of Nursing, aimed to describe secondhand exposure to e-cigarette vapors in children relative to influential factors of parental use. They sought to do so by comparing saliva and exhaled breath condensate to blood testing—the “gold standard” of analysis. They additionally aimed to detect exposure biomarkers and downstream effects of secondhand exposure in children, the behaviors of parents who use e-cigarettes relative to child cotinine levels, and the perceptions of said parents regarding secondhand exposure risk in children.

“Secondhand cigarette smoke exposure can alter endogenous chemicals in the body and negatively impact metabolic functioning and health,” investigators wrote. “Many cigarette smokers have turned to electronic cigarette use assuming less exposure for themselves and bystanders. Minimal to no research exists establishing the chemical exposure profile of children exposed to secondhand e-cigarette vapors.”

Rodriguez and colleagues designed a two-group comparison of parents and children with exposure, and parents and children without exposure. Measures of analysis included a parent-completed questionnaire; child blood via fingerstick; child saliva via passive drool; and child exhaled breath condensate.

The 3 biomatrices were analyzed through a high-resolution metabolomics test; the team additionally sought cotinine levels on child saliva. The parent surveys assessed their beliefs on secondhand e-cigarette exposure, which was described and expanded upon within focus groups.

The final analysis included 48 parent-child dyads in the primary analysis, plus 6 parents participating in follow-up focus groups. Investigators reported that the metabolites found in saliva and exhaled breathing condensate were moderate to highly correlated with those found in blood tests. Such metabolites that were found in the children exposed to secondhand e-cigarette vapor were associated with vaping cartridge-based chemicals.

What’s more, the metabolites observed in exposed children were linked to oxidative stress and altered dopamine production. Regarding cotinine, the only association with elevated levels was higher concentrations of nicotine in vaping cartridges.

In survey and focus group analyses, investigators noted that parents were predominately dual combustible and electronic cigarette users, and most were of the belief that secondhand vapor exposure was not harmful for children. Investigators additionally noted a consistent trend of struggle with nicotine addiction among the parents.

Contrary to the parents’ perceptions, investigators concluded with contributions toward evidence that secondhand e-cigarette vapor exposure is determinable in a variety of ways in children, and associated with harmful health risks.

“Children with secondhand e-cigarette vapor alone have lower mean cotinine levels compared to children with secondhand smoke and secondhand e-cigarette vapor exposures, indicating that children exposed to both are at higher risk,” the team wrote. “Parental beliefs that electronic cigarette use and secondhand e-cigarette vapor exposure is not harmful and parental addiction may present barriers to decreasing secondhand exposure and parental use cessations. PNPs and other healthcare professionals must address the harmful effects of secondhand e-cigarette vapor exposure in addition to secondhand smoke exposure with families.”

Reference

^{Rodriguez J, Yang I, Liang D, Close S, er al. Metabolites of Exposure and Downstream Effects Found in Children Exposed to Secondhand Electronic Cigarette Vapors. Paper presented at: NAPNAP National Conference on Pediatric Health Care. March 13 - 16, 2024. Denver, CO.}