Vaping Around Kids Is Far Safer for Them Than Smoking

By Kiran Sidhu. Kiran is a tobacco harm reduction fellow for Filter.

"Children absorb far less nicotine from people vaping around them indoors than they do from secondhand smoking, researchers found, suggesting that any secondhand absorption of other components of vapor is also likely to be very low.

Countries with substantial uptake of vaping have seen accelerated declines in the cigarette smoking which costs millions of lives each year. Yet valid concerns about passive smoking have often morphed into largely media-driven alarm over passive vaping—despite no good evidence that it is harmful.

Such fears have fueled debates over where vaping should be permitted, and they’ve been particularly pronounced when it comes to the potential impact on children. An Alabama law passed in 2023, for example, made it illegal to vape (or smoke) in a car with a child under 15 present, with a potential fine of up to $100.

The new study—conducted by researchers at University College London (UCL) and the SPECTRUM Consortium, and published in JAMA Network Open—set out to compare nicotine absorption levels in three groups of children in the United States: those exposed to secondhand smoke only, those exposed to secondhand vapor only, and those exposed to neither.

Children were categorized based on interviews with their parents or guardians. Those reportedly exposed to both smoke and vapor were excluded.

Blood samples from 1,777 children, aged 3-11, were then sent for analysis at a Centers for Disease Control and Prevention laboratory. There, concentrations of serum cotinine in the samples were measured—long regarded as a “precise and accurate marker of recent absorption of nicotine,” the researchers noted.

“Compared with children exposed to secondhand smoke, nicotine absorption was 83.6% lower in those exposed to secondhand vapor.”

Nicotine absorption was found to be “highest among children who were exposed to secondhand smoke only, followed by those exposed to secondhand vapor only,” the authors wrote.

The difference between those two groups was actually much bigger than the difference between the vapor-exposure group and the no-exposure group.

“[C]ompared with children exposed to secondhand smoke only, nicotine absorption was 83.6% lower in those exposed to secondhand vapor only and 96.7% lower in those exposed to neither,” the researchers found.

“Our study shows, using data from the real world rather than an artificial lab setting, that nicotine absorption is much lower from secondhand vapor than from secondhand smoking,” lead author Dr. Harry Tattan-Birch said in a press release. 

“Nicotine itself is of limited risk, but it shows what the highest possible exposure might be from secondhand vaping,” he continued. “Exposure to harmful non-nicotine substances present in vapor will likely be substantially lower still.”

Still, the research found that children exposed to secondhand vapor do absorb more nicotine than those exposed to neither smoke nor vapor. Is their exposure to nicotine and other substances something we should be at all worried about?

“The results show that the level of secondhand exposure to nicotine (and other harmful constituents) from being indoors while other people are vaping appears to be minimal,” Tattan-Birch, of the UCL Institute of Epidemiology & Health Care, told Filter.

From his perspective as researcher based in the United Kingdom, he noted that “this means there isn’t the same impetus to ban vaping indoors (e.g., in bars and workplaces) on health grounds alone as there was for smoking.”

Tattan-Birch and his colleagues don’t say that secondhand vapor is totally risk-free, however.

“[A]s secondhand vaping still exposes children to more harmful substances than no vaping or smoking exposure at all, it is best to avoid indoor vaping around children,” UCL’s Professor Lion Shahab, another of the authors, said in the press release.

But Shahab’s much stronger language about smoking in that situation—“should be avoided at all costs”—makes clear that parents or caregivers who switch from cigarettes to vapes are taking a big step forward. Most adults who vape in the UK and other countries previously smoked, and many people who smoke find that vaping is the only way they can quit.

“‘Passive vaping’ is unlikely to pose any health risks.”

Other experts go a little further.

“‘Passive vaping’ is unlikely to pose any health risks,” said Dr. Peter Hajek, professor of clinical psychology and director of the Health and Lifestyle Research Unit at Queen Mary University of London.

Hajek, who was not involved in the new study, publicly commented that it “confirms that, as expected, the amount of nicotine exhaled by vapers, that children and other bystanders are exposed to, is negligible.”

While cigarettes “release …  a number of more serious toxicants into the environment,” he noted, vapes release “no combustion products.”

Dr. Roberto Sussman, a physicist at the Institute of Nuclear Sciences, National Autonomous University of Mexico, is also among scientists who say that risks of secondhand vapor are grossly exaggerated.

Sussman previously explained to Filter how exhaled vaping aerosol rapidly evaporates and disperses, and how particulate matter from air pollution, even in indoor environments, is a far more valid concern. Globally, almost 2,000 children under 5 die because of air pollution each day.

The study authors seem to agree that secondhand vapor is not a substantial threat.

“This paper suggests that concerns about secondhand vaping may be somewhat overstated, with secondhand exposure to toxic substances likely to be very low,” Prof. Shahab said in the release."