Intraspecies Variation of Per- and Polyfluoroalkyl Substances Bioaccumulation in a Coastal Marine Organism Near a Megacity.

Intraspecies variation in pollutant bioaccumulation has received limited attention in field studies, which could cause bias for ecological and health risk assessment. In this study, 40 per- and polyfluoroalkyl substances (PFAS) and stable carbon and nitrogen isotope were analyzed in 43 individuals of Cynoglossus trigrammus collected from the coastal area of Shenzhen City, China, to explore the intraspecies variation in PFAS bioaccumulation. Total PFAS (Σ40PFAS) concentrations ranged from 40.0 to 192 ng/g, ww, and increased significantly with body length (p < 0.001). Positive relationships (p < 0.01) were observed for perfluorooctanesulfonate (PFOS), perfluorodecanoic acid (PFDA), perfluoropentanesulfonic acid (PFPeS), and perfluorohexanesulfonic acid (PFHxS), whereas negative relationships (p < 0.05) were observed for perfluorooctanoic acid (PFOA), N-methyl perfluorooctanesulfonamidoacetic acid (N-MeFOSE), and 11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS) with body length. Muscle-derived trophic levels also showed significant relationships but were different and weaker than those of body length. Quantile regression showed stronger size effects at high quantiles of whole-fish burden (τ = 0.90 and 0.95), and size-selective feeding (length ≥75th percentile) shifted dose distributions toward higher values. These results suggest that body length is an important indicator to identify the intraspecies PFAS heterogeneity and that size-selective processes might increase upper percentiles exposure and risks.