Bridging experimental PFAS kinetics and seafood safety in Litopenaeus vannamei

This study quantified the waterborne uptake, depuration, and food-safety translation of six priority per- and polyfluoroalkyl substances (PFAS), namely PFOS, PFOA, PFNA, PFHxS, PFBS, and GenX, in whiteleg shrimp (Litopenaeus vannamei) under controlled culture conditions. A two-phase uptake-depuration design was combined with concentration-response testing at 0.10, 1.00, and 10.0 μg L^-1 per analyte and environmental-modifier experiments across 10, 20, and 30‰ salinity, 24, 28, and 32 °C, and 1 versus 5 mg L^-1 dissolved organic carbon (DOC). Tissue PFAS concentrations increased with aqueous exposure throughout the tested range. Apparent uptake coefficients (k₁) differed significantly among analytes, with the highest mean values observed for PFOS (1.765 L kg^-1 d^-1) and PFNA (1.547 L kg^-1 d^-1). Growth-corrected elimination also varied significantly, yielding biological half-lives of 9.48 d for PFOS, 6.97 d for PFNA, 6.84 d for PFHxS, 5.59 d for PFOA, 3.79 d for PFBS, and 3.59 d for GenX. Relative to the 20‰/28 °C reference condition, mean apparent uptake increased by 18.9% at 10‰ salinity and 13.8% at 32 °C, but decreased by 7.4% at 30‰ salinity and 14.0% at 24 °C. Increasing DOC from 1 to 5 mg L^-1 reduced fitted k₁by 7.5-27.9%, depending on the analyte. Model-based translation to a 2 μg kg^-1 edible-tissue benchmark yielded safe-water estimates of 0.125-0.224 μg L^-1 for the four regulated PFAS. Overall, these findings provide a statistically supported kinetic framework for linking PFAS exposure in shrimp culture water with tissue accumulation, elimination behavior, and seafood-safety assessment.