Researchers used lab-grown human skin to determine if PFAS can enter our bloodstream through contact with this organ… And the answer is yes!
Why are they used? PFAS ?
PFAS are synthetic chemicals that resist degradation over time. Since the 1950s, they have been commonly used in frying pans, pots, food packaging, furniture, adhesives and clothing. They are in fact renowned for their resistance to heat, stains, oil, grease and water.
“Extremely persistent, PFAS are found in all compartments of the environment and can expose populations through air, food, water or the use of different products and everyday objects,” indicates Anses.
“It was thought that the electrical charge that gives them the ability to repel water and stains would make them unable to pass through the human skin membrane,” says research author Oddný Ragnarsdóttir. “But our analyses show that this theory does not always hold true and that in fact absorption through the skin could be a significant source of exposure of the body to these harmful chemicals,” continues the doctor.
17 different types of PFAS tested on skin
To reach this conclusion, Oddný Ragnarsdóttir and her colleagues examined 17 different types of PFAS.
To avoid using animal studies, the team used 3D models of human skin. They then applied samples of each PFAS to see what proportions were absorbed.
Of the 17 PFAS tested, 15 showed substantial skin absorption, i.e. at least 5% of the exposure dose. Some figures are high, such as the exposure dose examined for PFOA (perfluorooctanoic acid) which was 13.5%.
Penetration of PFAS into the skin: the role of the chain of carbone
According to the analysis, the quantity of chemical absorbed is linked to the length of its carbon chain*. Substances with longer carbon chains have lower absorption levels, while substances with shorter carbon chains are easier to absorb. For example, perfluoropentaenoic acid (PFPeA) was four times easier to absorb than PFOA.
“The industry is moving towards chemicals with shorter chains because they are considered less toxic, but the trade-off could be that we are taking in more of them. So we need to know more about the risks involved,” concludes Professor Stuart Harrad, co-author of the study.
The research discussed in this article is published in the journal Environment International.
*The carbon chain of an organic molecule is the way in which the different carbon atoms of this molecule are linked together.
