Pollution Characteristics, Sources, and Health Risks of Organochlorine Pesticides and Polychlorinated Biphenyls in Oviductus Ranae from Northern China

) from major production areas in Heilongjiang Province, China. OCPs and PCBs were detected in all samples. The total concentration of OCPs ranged from 11.7 to 67.9 ng/g (dry weight), while that of total PCBs ranged from 4.43 to 8.06 ng/g. Endosulfans constituted the predominant OCP group, accounting for 54.5% of ∑OCPs, with an α/β-endosulfan ratio (~2:1) indicative of recent agricultural input. Among DDTs, the dominance of p,p'-DDE and the absence of parent DDT suggested aerobic degradation of historical residues. For HCHs, the isomer profile (β-HCH predominance, α/γ-HCH = 0.27) pointed to weathered lindane sources. The PCB profile was uniquely dominated by lower-chlorinated congeners (PCB1 and PCB29), implying influences from atmospheric transport and/or in situ microbial dechlorination of legacy PCBs. The persistent organic pollutants (POPs) contamination profile in Oviductus Ranae reflects a combined influence of recent pesticide application, weathered historical residues, and long-range transport. Although the concentrations are below current regulatory limits, the cumulative and persistent nature of these POPs, coupled with the product's medicinal use, justifies a precautionary stance regarding long-term consumption. The distinct congener patterns underscore the necessity for future research to prioritize the environmental behavior and toxicology of dominant transformation products within such specific agro-ecosystems.