New research in Environment International proves for the first time that PFAS chemicals can permeate the skin and enter the bloodstream. PFAS Â (perfluoroalkyl substances) are widely used in industries and consumer products, like waterproof clothing and personal care items, for their water and stain-repellent properties.
While some PFAS have been banned, many are still used, and their toxic effects are not fully known. PFAS are also known to enter the body through inhalation or ingestion and can cause health issues like lowered immune response, impaired liver function, and decreased birth weight.
It was commonly believed that PFAS couldn’t penetrate the skin, but recent studies link personal care products to PFAS in blood and breast milk. Comprehensive research confirms that most PFAS can be absorbed through the skin.
Dr. Oddný Ragnarsdóttir, the lead author, conducted this research during her PhD at the University of Birmingham. She explained that it was previously thought PFAS couldn’t be absorbed due to their ionized state, which repels water and stains. However, their research shows that PFAS can enter the body through the skin, potentially causing significant exposure to these harmful chemicals.
Researchers investigated 17 widely used PFAS, focusing on those regulated by the EU’s Drinking Water Directive. They used 3D human skin models to test how much of each chemical was absorbed, unabsorbed, or retained in the skin. Of the 17 PFAS, 15 showed significant skin absorption, with at least 5% of the dose absorbed. For PFOA, 13.5% entered the bloodstream, and 38% stayed in the skin, potentially entering circulation later.
The study found that PFAS absorption depends on the length of their carbon chains. Longer chains showed lower absorption, while shorter chains, used to replace longer ones like PFOA, were more easily absorbed. For example, perfluoro pentanoic acid was absorbed four times more than PFOA at 59%.
Dr. Mohamed Abdallah emphasized the importance of studying the dermal absorption of a wide range of PFAS. Professor Stuart Harrad noted that while shorter-chain PFAS are considered less toxic, they might be absorbed more easily, highlighting the need to understand the associated risks.
Journal reference:
- ,Oddný Ragnarsdóttir, Mohamed Abou-Elwafa Abdallah et al., Dermal bioavailability of perfluoroalkyl substances using in vitro 3D human skin equivalent models. Environment International. DOI: 10.1016/j.envint.2024.108772.