Longitudinal Trends in Per- and Poly-fluoroalkyl Substances among Midlife Women from 1999 to 2011

Abstract

PDS 62: Chemicals and metals: exposure and biomarkers, Johan Friso Foyer, Floor 1, August 28, 2019, 10:30 AM - 12:00 PM Background/Aim: Per- and poly-fluoroalkyl substances (PFAS) are ubiquitous chemicals that have received enormous attention due to water contamination and consumer product use. Although previous studies have explored temporal trends using repeated cross-sectional data, little is known about longitudinal trends and differential patterns of exposure by population characteristics. Objective: We examined longitudinal trends of serum PFAS concentrations in midlife women from the Study of Women’s Health Across the Nation (SWAN) and whether trends differed by menopausal status or race. Methods: Serum concentrations of 11 PFAS homologues (6 perfluoroalkyl carboxylic acids, PFCAs; and 5 perfluoroalkane sulfonic acids, PFSAs) were measured in 75 midlife White, Black and Chinese women with blood samples collected in 1999-2000, 2002-2003, 2005-2006, and 2009-2011. Time trajectories were assessed using mixed-effect models with interaction terms for time with race and menopausal status, adjusting for age at baseline and study site. Results: Concentrations of all PFSAs, linear and branched perfluorooctanoic acid (PFOA) decreased significantly, whereas perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDeA), and perfluoroundecanoic acid (PFUA) increased significantly from 1999 to 2011. Premenopausal women with menstrual bleeding since the last visit had consistently lower PFAS concentrations. Temporal trends in PFAS concentrations varied significantly across racial groups: white women had the highest concentrations of linear PFOA at baseline but differences between racial groups narrowed over time. Results remained unchanged with further adjustment for education and financial strain. Conclusions: Our results suggest significant intra-individual declines in serum concentrations of legacy PFASs and increase in emerging compounds from 1999 to 2011 in midlife women. These changes are consistent with the phase-out of PFOA, perfluorooctane sulfonic acid (PFOS) and precursors since 2000-2002. Postmenopausal women had higher concentrations over time suggesting that ovarian aging might lead to increased PFAS concentrations. Our findings also indicate that temporal trends in PFAS concentrations are not uniform across racial groups.