A multiscale assessment of POPs and PAHs in freshwater fish: Linking environmental monitoring, GA-MLR modeling and toxicokinetic prediction to assess potential transfer to humans.

This study integrates environmental monitoring, multivariate modeling, and toxicokinetic prediction to investigate the occurrence of PAHs, PCBs, and OCPs in Croatian freshwater fish and factors associated with their tissue concentrations.. Sediment and chub (Squalius spp.) data from Croatian rivers across the Danube and Adriatic basins were evaluated. Fluoranthene and pyrene were the most abundant PAHs in both chub and sediment, while high-molecular-weight PAHs were infrequently detected and generally occurred at low concentrations. in fish tissues. In contrast, PCBs and OCPs, although present at low levels in sediments, were consistently accumulated in fish, reflecting their persistence and strong bioaccumulative potential. Multivariate modeling indicated that PAHs was primarily associated with acute toxicity-related descriptors and PCBs/OCPs with uptake, partitioning, metabolism, and elimination descriptors. Lipid content was the dominant, but not a consistent, predictor of PCB and PAH burdens, whereas age and body size showed negative associations, consistent with growth dilution and metabolic effects. OPERA-derived toxicokinetic modeling provided illustrative predictions of organ-specific contaminant distribution, with PCBs showing the highest accumulation in lipid-rich tissues such as the liver. These findings demonstrate the value of integrating environmental monitoring with statistical and toxicokinetic modeling to improve understanding of contaminant occurrence and support future assessments of dietary exposure.