Use of a capillary blood collection device to monitor exposure to per- and polyfluoroalkyl substances (PFAS) in Veterans living in proximity to potential sources of environmental contamination

BACKGROUND: Environmental exposure biomonitoring commonly requires a laboratory blood draw followed by processing, frozen storage, and transport of plasma or serum. Self-collection of blood onto matrices that are stable at ambient temperatures is an attractive approach for the measurement of circulating environmental chemicals. OBJECTIVES: To validate the measurement of per- and polyfluoroalkyl substances (PFAS) in capillary whole blood (WB) collected and dried onto a paper matrix using the Drawbridge Health OneDraw device. To explore sources of personal and environmental PFAS exposure in Veterans receiving care at the Central Arkansas Veterans Healthcare System (CAVHS). METHODS: PFAS concentrations in dried capillary WB collected with the OneDraw device were compared to matched venous blood plasma PFAS concentrations in 133 Veterans receiving care at the CAVHS. PFAS were quantified using ultra-high-performance liquid chromatography/tandem mass spectrometry (UHPLC-MS/MS). Associations between subjects' demographic characteristics, self-reported exposure factors, and PFAS concentrations in dried capillary WB were assessed. Geometric mean PFAS concentrations were visualized by subjects' county of residence. RESULTS: Measurement of 27 PFAS in dried capillary WB on OneDraw collection strips was robust with limits of quantification of 0.1 ng/mL for most analytes. In 133 Veterans, dried capillary WB levels of 10 PFAS were strongly correlated with venous blood plasma PFAS levels. WB PFAS concentrations were lower than venous blood plasma PFAS concentrations, reflecting selective partitioning of these compounds into plasma versus blood cells. WB concentrations of four PFAS (PFOA, PFOS, PFHxS, and PFNA) varied by sex and age at the time of blood draw and were associated with the primary source of drinking water. SIGNIFICANCE: WB samples collected onto dried paper matrices, are a practical and scalable alternative to conventional venous blood draws for PFAS biomonitoring. This approach facilitates remote, repeated sampling without the need for clinical infrastructure, enabling broader participation in exposure studies. IMPACT STATEMENT: Tracking environmental exposures in military, occupational, and community contexts has been challenging, particularly due to the lack of a practical workflow for capturing biological samples without a clinical infrastructure. This has led to a reduced ability to capture personal exposure data, in turn, limiting the analyses of the impact of these exposures on long-term health. We developed and validated a robust method using a self-contained, blood collection device for PFAS exposure biomonitoring as a proof-of-concept for broader adoption of this approach to enable larger-scale, longitudinal studies of exposure to PFAS and other classes of environmental chemicals. This method can be used to improve the evaluation of exposure-outcome relationships and provides a foundation for evidence-based policy decisions for health care and benefits.