This story has been updated with a comment by Oral-B.
The American Dental Association recommends daily cleaning between teeth using dental floss or another interdental cleanser that can help prevent tooth decay and gum disease. But a new study suggests that some types of dental floss and other behaviors can actually increase the amount of toxic chemicals in the body.
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The research, published this week in the Journal of Exposure Science and Environmental Epidemiology, comes from the Silent Spring Institute in collaboration with the University of California, the Berkeley Public Health Institute. For the study, scientists examined the blood samples of 1
The participants, half of whom were white or African-American, are part of the childhood and university development studies, a multigenerational analysis of environmental chemicals on the disease.
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To understand behavioral changes, the researchers compared blood measurements with interviews with women asking questions about nine behaviors that could lead to more exposures to PFAS, according to a press release. They also tested the presence of PFAS chemical markers in six different interdental threads.
"In addition to specialized industrial applications and use in fire-fighting foams, PFAS is often used in consumer products," according to the research. "More commonly, they are used in non-stick and water-resistant coatings, stains or greases, which are applied to a wide range of products, including food packaging, cookware, rugs, furniture, textiles and outdoor equipment. " PFAS tend to be detected in water, soil and American bodies due to their "extensive use and persistent nature".
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According to the study, women who used dental floss with a particular dental floss – Oral-B Glide – had higher levels of perfluorohexanosulfonic acid PFAS (PFHxS) than women who did not . The National Institutes of Health notes that PFHxS has previously been linked to high cholesterol and impaired thyroid function.
To further analyze the result, the researchers tested the fluorine (a PFAS chemical marker) in 18 different threads using a technique called gamma-ray-induced spectroscopy particles
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When they did, the three Glide products tested were positive. Two similar store-branded products marketed as Oral-B Glide, plus another marketed with "single-stranded teflon fiber" were also positive for fluorine.
Previous reports have highlighted the use of Glide of Teflon-like compounds. Teflon is the trade name for polytetrafluoroethylene PFAS, which the environmental working group has warned against using dental floss because of the risks of cancer, hormonal disorders, brain and liver problems, and low birth weights.
Thursday, Procter & Gamble, creator of Crest and Oral-B wire Atlanta, said: "We have confirmed that none of the substances contained in the report has been used in our dental floss. The safety of people who use our products is our top priority Our dental floss is subjected to extensive safety testing and we are behind the safety of all our products. "
Participants may have been exposed to PFAS chemicals from other sources not included in the research or like swallowing contaminated dirt, eating seafood from contaminated water. While the author of the Katie Boronow study recognized it in a statement to INSIDER, the researchers reiterated that the study is based on self-reported use, including the effects of dental floss.
This is the first study to find "dental floss tests with PTFE-based toothpaste. Dental floss could contribute to individual body weight of PFAS, but more data is needed to verify this result," the researchers wrote.
The general hygiene lesson: you might want to avoid dental floss with PFAS, said Boronow in a note  »RELATED: 4 ways to save on dental care in the Atlanta subway – even without insurance
In addition to the results of dental floss, the researchers noted higher levels of PFAS when the participants:
- had stain-resistant carpets or furniture
- lived in a city with a supply of PFAS-contaminated drinking water  ate food prepared in coated cardboard containers (African-American women in particular)
The authors also noted that in this particular study, "African Americans ate potato chips more often than non-Hispanic whites, so we infer that they could also consume more fast foods like hamburgers, which are sold in paper wrappers. "Fluoride chemicals are often detected in fast food packaging.
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One potential limitation, according to the study, is that there are other behaviors that may contribute to PFAS exposure that researchers have not measured. This is why any racial differences concerning PFAS chemicals have been left unexplained. Another limit: the number and position of the participants. But the authors report comparable figures with a nationally representative sample.
Future work should plunge into Hispanic and Asian Americans, as racial differences could help identify "major exposure routes," according to the study.
Water, for example, is considered a threat to public health that most consumers can not do much, "this study strengthens the evidence that consumer products are [also] an important source of exposure to PFAS, "said Boronow. "Restricting these chemicals from products should be a priority for reducing levels in people's bodies."
Read the full study on nature.com.