Your smartwatch band may contain harmful forever chemicals, researchers warn
NEW YORK, Jan. 14 (UPI) -- Wearing a smartwatch or fitness tracker may not be a boon to your health after all. Rather, it could expose the skin to harmful "forever chemicals."
The bands contain a class of synthetic chemicals present in many everyday products, such as cookware, cosmetics and food packaging, researchers from the University of Notre Dame in Notre Dame, Ind., noted.
And exposure to these chemicals can lead to liver damage, thyroid disease, obesity, decreased fertility, certain cancers and other health problems, studies have shown.
For this investigation, researchers tested the composition of smartwatch bands sold by Apple, Apple/Nike, CASETiFY, Fitbit, Google, King of Kings, Modal, Samsung, Tighesen and Vanjua. But they declined to identify the brands that tested positive.
"We do not have the resources nor the mission to 'indict' or 'clear' any brand, but rely on concerned consumers to help hold the industry to transparency when it comes to PFAS in their products," study co-author Graham Peaslee told UPI.
Called PFAS for short, perfluoroalkyl and polyfluoroalkyl substances repel water, sweat and oil.
In particular, pricier smartwatch bands composed of fluorinated synthetic rubber harbor high levels of a specific type of PFAS -- perfluorohexanoic acid, or PFHxA.
"This study was unusual in that we have rarely ever seen just one PFAS in a consumer product. There are typically dozens of different types measured -- and this one was heavily dominated by just one: PFHxA," said Peaslee, a professor emeritus in the Department of Physics and Astronomy at the University Notre Dame.
"The amount that was present -- and readily extractable -- was hundreds to thousands of times higher than we had seen in other products," Peaslee said. Overall, he added, that's "a very unusual source of PFAS that can get directly onto your skin."
Peaslee and his colleagues published their findings recently in Environmental Science & Technology Letters, a journal of the American Chemical Society.
While the durability of these wristbands is good for sweaty workouts, it also presents a possible source for these compounds to be readily absorbed into the body, investigators said.
Researchers investigated several commercially available watch bands for the presence of fluorine, as well as 20 individual PFAS. They screened 22 wristbands from a variety of brands and at different price tags. Most bands were new, but a few had been worn.
All 13 bands advertised as being made from fluoroelastomers had the element fluorine. But two of the nine bands that did not advertise being composed of fluoroelastomers also contained fluorine, which suggests the potential presence of PFAS.
Wristbands that cost over $30 had more fluorine than those priced less than $15.
After a chemical extraction, researchers checked all wristbands for 20 different PFAS. PFHxA was most common, existing in nine of 22 tested wristbands.
The median PFHxA concentration was almost 800 parts per billion, and one sample exceeded 16,000 ppb. For comparison, the team's research in 2023 on cosmetics found a median concentration of about 200 ppb of PFAS.
"We found that several watch bands contained very high extractable concentrations of a single PFAS, PFHxA, which is very concerning as these products are regularly worn in contact with the skin," said Alyssa Wicks, the study's first author and a graduate student in Peaslee's lab at Notre Dame.
"As a PFAS researcher, I have not seen concentrations this high, especially for just a single type of PFAS, in any other wearable consumer products," Wicks said.
Scientists don't know how readily the skin absorbs PFHxA, or the potential health hazards it poses once it does.
In the study's appendix, researchers listed the wristbands they evaluated. However, "the sample set is so small that we don't have sufficient statistics to assert whether all companies are affected, or all products from a particular company are included," Peaslee said.
Wicks added that the team recommends purchasing lower-cost wristbands made from silicone. If a consumer wants to buy a higher-priced band, they suggest reading product descriptions and avoiding anything listed as containing fluoroelastomers.
Other experts praised the researchers for checking the chemical concentrations in wristbands of fitness trackers.
"It's an interesting study published in a high-quality journal," said Courtney Carignan, an assistant professor at Michigan State University in East Lansing and an expert in PFAS exposures and health effects. She was not involved in the study.
Carignan added that "it's concerning to learn these chemicals can be in some watch wristbands at relatively high concentrations."
Such chemicals affect immune function and hormone cholesterol levels, as well as increase the risks for certain cancers, she said, advising that consumers ask suppliers whether products are PFAS-free.
People should limit wearing these chemical-laden wristbands and avoid storing them near clothing, especially underwear, said Miriam Diamond, a professor at the University of Toronto's School of the Environment. She has studied PFAS in consumer products.
"This study adds to the many others showing the environmental debt we're building up," Diamond said. "PFAS is truly a 'forever' chemical."
