Advancing PFAS Biomonitoring in Hair: Rapid Analytical Method and Global Comparison of US Exposure

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are synthetic chemicals used in a wide range of consumer and industrial products. Their chemical stability and resistance to degradation lead to environmental persistence, raising concerns about human exposure and health risks. Although PFAS have been extensively monitored in ecological and traditional biological matrices, limited research has studied their presence in human hair. This study aimed to evaluate PFAS exposure in a New York population and contribute to the growing evidence supporting hair as a viable matrix for PFAS biomonitoring. A quantitative LC-MS/MS method for PFOA, PFNA, and PFHpA in human hair was validated according to ANSI/ASB Standard 036 guidelines, demonstrating linearity across a calibration range of 0.3-25 pg/mg. Real-case hair samples (n = 26), collected from individuals living in New York, were analyzed using LC-MS/MS. PFHpA was detected in 100% of the samples, with a median concentration of 14.11 pg/mg. In contrast, PFOA and PFNA were detected in 30.8% and 7.7% of samples, respectively, with median concentrations of 0.15 pg/mg for both compounds. The New York cohort had a unique PFAS profile, with lower PFOA and PFNA detection than some Asian cohorts but higher PFHpA levels than European and Asian studies. These findings highlight ongoing human exposure to legacy and emerging PFAS, demonstrating the utility of hair as a tool for monitoring chemical exposure trends. This research underscores the importance of ongoing PFAS surveillance to inform environmental health initiatives, guide regulatory efforts, and protect populations at potential elevated risk due to occupation, geography, or socioeconomic factors.