Title: Longitudinal measures of perfluoroalkyl substances (PFAS) in serum of Gullah African Americans in South Carolina: 2003-2013.
Authors: Gribble, Matthew O; Bartell, Scott M; Kannan, Kurunthachalam; Wu, Qian; Fair, Patricia A; Kamen, Diane L
Published In Environ Res, (2015 Nov)
Abstract: BACKGROUND: Charleston Harbor has elevated concentrations of PFAS in dolphins, but local human exposure data are limited. OBJECTIVES: We sought to describe PFAS serum concentrations' temporal trends among Gullah African American residents of coastal South Carolina. METHODS: Longitudinal measures of PFAS in blood serum from a Gullah clinical sample, without lupus, were examined using spaghetti plots and visit-to-visit change scores (e.g., differences in concentrations between visits) among the 68 participants with repeated measures available. We also modeled population-level trends among the 71 participants with any data using proportionate percentile models, accounting for clustering through robust standard errors. In a post-hoc analysis we examined heterogeneity of temporal trends by age through mixed-effects models for the log-transformed PFAS compounds. RESULTS: Population concentrations of PFOS dropped approximately 9 (95% CI: 8, 10) percent each year over 2003-2013. This was concordant with individual PFOS trajectories (median PFOS change score -21.7 ng/g wet weight, interquartile range of PFOS change scores: -32.8, -14.9) and reports for other populations over this time period. Several other compounds including PFOA, PFHxS, and PFuNDA also showed a population-level decrease. However, examination of individual trajectories suggested substantial heterogeneity. Post-hoc analyses indicated that PFAS trajectories were heterogeneous by age. CONCLUSIONS: Many PFAS compounds are decreasing in a sample of Gullah African Americans from coastal South Carolina. There may be age differences in the elimination kinetics of PFASs. The possible role of age as a modifier of PFAS serum trends merits further research.
PubMed ID: 25819541
MeSH Terms: Adolescent; Adult; African Americans*; Aged; Aging/blood; Alkanesulfonic Acids/blood*; Child; Chromatography, High Pressure Liquid; Environmental Exposure/analysis*; Environmental Exposure/statistics & numerical data; Environmental Pollutants/blood*; Female; Fluorocarbons/blood*; Humans; Longitudinal Studies; Male; Middle Aged; Models, Statistical; South Carolina; Tandem Mass Spectrometry; Young Adult