By Linda Carroll

(Reuters Health) – Exposure to secondhand chemicals emitted from e-cigarettes is on the rise among middle- and high-school students, a new study suggests.

A survey that included tens of thousands of U.S. teens found that exposure to secondhand aerosols from e-cigarettes rose from one in four students in 2015 to one in three in 2018, researchers reported in JAMA Network Open.

Other research has found that secondhand exposure to e-cigarette vapor can “pose health risks to bystanders,” said the study’s lead author Andy Tan, an assistant professor in social and behavioral sciences at the Dana Farber Cancer Institute and the Harvard T.H. Chan School of Public Health in Boston.

“The vapor contains elevated levels of nicotine, particulate matter, glycerin propylene glycol, formaldehyde, polycyclic aromatic carbons and heavy metals,” Tan said. “These substances are known to have health risks in vulnerable populations, including children and teens.”

For example, Tan said, one recent report described a Florida teen with asthma who had an attack after being exposed to secondhand e-cigarette vapor.

To take a closer look at the number of teens being exposed to secondhand e-cigarette vapor, Tan and colleagues turned to the National Youth Survey, which included data from about 17,000-20,000 schoolchildren in each year between 2015 and 2018.

Survey participants were asked how often they breathed smoke from someone who was smoking combustible tobacco products and how often they breathed vapor produced by someone using an e-cigarette in an indoor or outdoor public place in the past 30 days.

The researchers found that self-reported exposure to e-cigarette vapor rose from 25.2% in 2015 to 33.2% in 2018. During the same period, exposure to combustible cigarette smoke was declining slightly, with about half of students saying they had been exposed to secondhand smoke.

Tan hopes the findings will spark regulators and parents to find ways to cut back on the availability of vaping products to schoolkids. While there are many laws in place that restrict smoking traditional cigarettes in public places, few have addressed the issue of secondhand exposure to vaping, Tan said.

Making matters worse, people often don’t know when they are exposed to vapors because the output from e-cigarettes doesn’t have the distinctive tobacco smoke smell. Someone walking down the street might catch a whiff of mango, cucumber or watermelon and not know they were inhaling e-cigarette aerosols, Tan said.

This study “reaffirms what a lot of us are concerned about,” said Dr. Panagis Galiatsatos, director of the Tobacco Treatment Clinic at the Johns Hopkins School of Medicine in Baltimore, Maryland.

“There is the possibility that secondhand e-cigarette ‘smoke’ will turn out to be as bad as secondhand smoke from combustible cigarettes,” he noted.

“I have a patient who developed acute lung disease from another’s vaping,” Galiatsatos said. “Just as there are warnings about secondhand smoke from traditional cigarettes, we should also have a campaign for electronic versions.”

Galiatsatos worries that people could be hurt by e-cigarette vapor before there’s scientific proof of the dangers.

“To me it’s very scary,” he said. “I love science. But there will probably be a lot of people who get addicted and hurt before the science catches up. We don’t want to have to play catchup with e-cigarettes like we did with combustible cigarettes 50 years ago.”

SOURCE: JAMA Network Open, online August 28, 2019.