Characterization of the Distribution and Fate of Neutral Per- and Polyfluoroalkyl Substances (PFAS) in Indoor Environments Including the Role of Clothing

Per- and polyfluoroalkyl substances (PFAS) are manufactured chemicals widely used in consumer products, but some are associated with negative health effects. Consumer products may release PFAS into indoor environments, where many people spend most of their time. However, few indoor measurements of PFAS exist, especially for the United States. The goal of my research is the characterization of the distribution and fate of neutral PFAS in North Carolina homes, with a particular focus on the role of clothing as a source and mediator of PFAS exposure. This goal was motivated by a literature review and research gaps identified therein. First, I measured nine neutral PFAS in indoor air and in initially PFAS-free cotton cloth during the Indoor PFAS Assessment (IPA) Campaign. I used the results to derive cloth-air partition coefficients for six PFAS and to show that clothing stored in dressers accumulates different PFAS than hanging cloth. Further, I examine partitioning of neutral PFAS from indoor air to settled dust, airborne particles, dryer lint, and heating and air conditioning (HAC) filters. Based on a comparison to the results for the cloth, I emphasize the importance of fabrics and clothing as a sink and potential secondary source of PFAS in homes. I also show that ventilation to the outdoors is a major pathway for the release of neutral PFAS from homes. Lastly, I investigate PFAS emissions from waterproof textiles. I show that fluorotelomer alcohols (FTOHs) are present in and emitted from all 11 randomly selected new and used rain jackets that I tested. Using data from an emission chamber and an iodide high-resolution time-of-flight chemical ionization mass spectrometer (I-HR-ToF-CIMS) to obtain FTOH emission profiles, I demonstrate that FTOH emissions are generally limited by internal diffusion; specifically, that they behave like volatile organic compounds (VOCs). My results further suggest that old, used rain jackets may emit FTOHs at higher rates than new jackets. The information about PFAS emission and partitioning gleaned from my research will enable the use of transport and exposure models that can help to assess the exposure and risk posed by currently used and new PFAS.