Characterizing Metals and PFAS leaching from Tampons and their Adverse Effects on a Human Vaginal Mucosa Cell Model - Project Summary More than 300 million people worldwide menstruate every day. However, the health of menstruators has been largely overlooked in medical research, health care, and policy but access to safe menstrual products is para- mount. Due to their effectivess and convenience, up to 86% of menstruators in the United States use tampons. Unlike other menstrual products, tampons absorb and retain menstrual fluid in the vagina. Tampons come into direct contact with the vaginal mucosa which has a large surface area and is highly permeable. This unique properties makes the vaginal absorption of chemicals 10-80 times more efficient than the oral route. Our research group conducted the first study of metals in tampons and found measurable concentrations of 16 metals in tampons; 12 metals were detected in all the tampons we tested and also found PFAS in the absorbent material of tampons. This resulted in the Chair of the Senate Appropriates Committee requesting the US Food and Drug Administration (FDA) to evaluate whether any steps were needed to ensure tampon safety. This is crucial as metals and PFAS are known endocrine disruptors, and some have been identified as carcinogens. However, there are almost o data available about toxicants in tampons, their bioavailaibility and adsorption through the vagina and the potential effect on vaginal cells. To address these data gaps, the goal of this proposed project is to characterize for the first time the leaching of metals and PFAS from tampons, as well as to investigate the vaginal absorption of metals and PFAS and their adverse effects on vaginal cell function and viability. We will investigate the leaching of metals and PFAS from tampons through in vitro bioelution studies, using a range of tampons from different brands and adsorbencies to simulate real-life exposure scenarios. These experiments will assess the release of metals and PFAS under conditions mimicking typical tampon use, using simulated vaginal and menstrual fluids. Furthermote, using a 3D vaginal mucosa model, we will study the absorption of metals and PFAS by vaginal epithelium cells and their penetration into the underlying tissue, focusing on their systemic absorption and toxicity. We will evaluate the direct effects of metal and PFAS exposure on vaginal cell structure and function, using immunofluorescence and viability assays to measure cellular changes, immune response, and reproductive markers. These experiments will provide insight into the potential gynecological and reproductive health risks associated with metal and PFAS exposure. Our study will provide essential data on exposure risks, vaginal toxicity, and regulatory standards, supporting efforts by the International Organization for Standardization (ISO) to establish global safety standards for menstrual products by 2027.