Researchers have discovered that permanent chemicals, known as PFAS (perfluoroalkyl substances), can be absorbed by human skin. These substances, renowned for their persistence in the environment, are widely used in various consumer products for their water-repellent and stain-resistant properties.
Published in
Environment International, this new study reveals for the first time that PFAS can cross the skin barrier and enter the bloodstream. These chemicals are commonly found in cosmetics as well as in other consumer goods. Despite regulations banning some of these substances, many remain in use, and their toxic effects are not yet fully understood. It is already known that PFAS can enter the body through ingestion or inhalation, causing harmful effects such as reduced immune response, liver problems, and decreased birth weight.
The study, led by Dr. Oddný Ragnarsdóttir from the University of Birmingham, is the most comprehensive evaluation to date of PFAS skin absorption. It shows that most of these substances can enter the body through the skin. Researchers studied 17 commonly used PFAS by applying these substances to 3D models of human skin grown in the lab. These models, made up of multilayered tissues, mimic the properties of human skin.
The results are alarming: out of the 17 PFAS tested, 15 showed substantial skin absorption, meaning at least 5% of the exposure dose passed through the skin barrier. For perfluorooctanoic acid (PFOA), one of the most regulated PFAS, absorption reached 13.5%, with an additional 38% retained in the skin, raising concerns about potential long-term absorption. The study also revealed that the carbon chain length of PFAS affected their absorption levels: short-chain compounds were absorbed more easily than long-chain ones. For example, perfluoropentanoic acid (PFPeA) was absorbed four times more than PFOA.
Dr. Mohamed Abdallah, co-author of the study, emphasizes the importance of these findings in understanding the risks of skin exposure to a wide range of PFAS. He calls for future research to evaluate the risks associated with these toxic substances, rather than focusing on one chemical at a time. Professor Stuart Harrad, also a co-author, notes that the industry is moving towards shorter-chain PFAS, considered less toxic but potentially more absorbable through the skin.
This study highlights the need to reconsider the safety of products containing PFAS and to intensify research efforts to better understand their impacts on human health.
Article author: Cédric DEPOND