Flossing – the tooth kind, not the thing 10-year-olds are obsessed with – along with a whole host of common behaviors and consumer products could be linked to exposure to toxic pollutants known as PFAS.

PFAS are a group of chemicals defined as "a public health concern" by the US Centers for Disease Control and Prevention (CDC) and linked to numerous health problems in humans, such as chronic kidney disease, numerous forms of cancer, and decreased fertility. Despite being human-made, they can be found everywhere across the world, from fast food packaging and non-stick frying pans to drinking water and living organisms.

This new study, published in the Journal of Exposure Science & Environmental Epidemiology, highlights how certain everyday behaviors can also leave you at risk of exposure to these nasty substances.

Researchers led by the Silent Spring Institute in Massachusetts measured levels of 11 different PFAS chemicals in blood samples from 178 middle-aged women in the US. Women who used dental floss tended to have higher levels of a type of PFAS called PFHxS in their blood. To back up their findings, the team then looked for the presence of fluorine, a marker for PFAS, in different dental floss products. They found that three Oral-B Glide products tested positive for fluorine.

It's unclear whether these higher levels exceed "safe levels" of exposure to PFAS, however, it's fair to argue these findings are not exactly cheery news. 

“This is the first study to show that using dental floss containing PFAS is associated with a higher body burden of these toxic chemicals," lead author Katie Boronow, a staff scientist at Silent Spring, said in a statement. "The good news is, based on our findings, consumers can choose flosses that don't contain PFAS."

Another consumer product that stuck out in the research was fast food packaging. The team revealed that African American participants, but not white participants, who regularly ate french fries from coated cardboard containers had higher levels of four different PFAS chemicals in their blood.

On the other hand, white American women had higher levels of two PFAS chemicals, PFOA and PFHxS, in their blood compared to the African American participants. However, the study was not able to explain the differences in exposure levels between different ethnic backgrounds.

"Other consumer products known to contain PFASs based on product testing include dental floss, nonstick cookware, ski and floor waxes, and thread seal tape," the study reads.

The researchers also found that exposure to stain-resistant carpets was linked to higher levels of PFAS. Living in a city was also shown to be a risk factor, most likely due to PFAS-contaminated drinking water.

"Overall, this study strengthens the evidence that consumer products are an important source of PFAS exposure," added Boronow. "Restricting these chemicals from products should be a priority to reduce levels in people's bodies."