New study: Children of smokers have nicotine on their hands

According to a new study about thirdhand smoke (THS), indoor smoking bans can only offer limited protection to young children who live with a smoker, since nicotine residue stays in the smoker’s environment. In fact, nicotine levels were found to be especially high on the hands of 2- to 4-year-olds.

This research, published last month in the journal Tobacco Control, was conducted by researchers at the CCHMC, the University of Cincinnati, and San Diego State University. Scientists investigated environmental factors, demographic factors, and clinical findings of illness. They used hand wipes on kids to measure hand nicotine levels. The study builds upon one from 2017, which had similar initial findings but focused on a smaller sample group.

The 2019 study confirms previous research that smoking poses a potential danger to children even when smokers take their cigarettes outside. That’s because of THS, a film of chemicals left over from smoking. THS can settle and cling to household surfaces, then disperse back into the air when disturbed. People can breathe in THS, ingest it orally, or get it through their skin.

Work in this relatively new area has increased only within the last decade or so, but researchers currently think that THS especially affects the liver, lungs, and our healing ability. In one 2013 study, it was shown to damage DNA in human cells. Young kids are more at risk from THS because they spend more time indoors, and can be surrounded by contaminated objects, researchers say.

Dr. Melinda Mahabee-Gittens, a primary co-author of the 2019 study and a physician in the Division of Emergency Medicine at Cincinnati Children’s Hospital Medical Center (CCHMC), told Simplemost, “We have been making steady progress, and I’m looking forward to our further study to understand the clinical effects of thirdhand smoke on children. That will mean we’re getting closer to understanding how to keep children safe from tobacco smoke pollutants.”

The increased amounts of nicotine on the hands of 2- to 4-year-olds may be because kids at that age are more likely to explore their homes with their hands. Babies up to age 1 also experienced high exposure levels. Scientists also discovered that kids in apartment buildings had 42 percent higher hand nicotine levels than those in single-family homes. Nicotine levels were highest on kids’ hands when six or more cigarettes were smoked per day.

Interestingly, the hand nicotine levels of children were three times higher than those of nonsmoking adults in the same house. This might be the result of better handwashing habits in adults. Another good reason to teach that behavior to kids!

Children that had high levels of nicotine were 5.9 times more likely to also experience cough or congestion. They were also more likely to have asthma or bronchitis. These findings confirm the idea that THS has health-related implications.

Ultimately, though, scientists must continue to investigate how THS works. This is especially important, said Mahabee-Gittens, because THS can get more toxic with age. It can also react with ambient compounds to create secondary pollutants.

“We’ve only begun to scratch the surface here,” Mahabee-Gittens said. “There’s a lot of work to do in this field. We need large studies to examine how THS is associated with children’s health, and whether THS exposure is associated with some of the same illnesses as secondhand smoke exposure.”