Phosphorus-Containing Poly- and Perfluoroalkyl Substances in Marine Top Predators from the East China Sea: Temporal Trends, Tissue- and Species-Specific Accumulation

Poly- and perfluoroalkyl substances with phosphorus headgroups (P-PFAS) are emerging alternatives to legacy perfluoroalkyl substances, and research on their environmental fate is urgently needed. We measured P-PFAS concentrations in liver and other tissues (i.e., heart, intestine, spleen, kidney, pancreas, stomach, lung, muscle, skin, and blubber) from finless porpoises and whales stranded along the East China Sea coast during 2009 and 2019. The median hepatic concentrations of major P-PFAS, including perfluorohexanephosphonate, perfluorooctanephosphonate, perfluorodecylphosphonate (PFDPA), 6:2 polyfluoroalkyl phosphate monoester (6:2 monoPAP), 8:2 monoPAP, and 8:2 polyfluoroalkyl phosphate diester (8:2 diPAP), were 2.48, 4.32, 2.72, 1.74, 1.66, and 1.41 ng/g wet weight (ww), respectively. The median hepatic ΣP-PFAS concentrations significantly increased from 15.3 ng/g ww (2009-2010) to 17.7 ng/g ww (2018-2019) (p < 0.01), with PFDPA as the primary contributor (1.21 vs 4.23 ng/g ww, p < 0.01). Analysis of tissue distribution revealed that perfluorophosphonates (PFPAs) preferentially accumulated in liver, exhibiting a pattern similar to but more pronounced than that of legacy PFAS with equivalent chain lengths. Comparison between finless porpoises and minke whales indicated lower PFPA accumulation in the latter, potentially due to reduced metabolic efficiency. This study highlights the increasing temporal trend and high accumulation potential of PFPAs.