PCB concentrations in freshwater wild brown trouts (Salmo trutta trutta L) from Marche rivers, Central Italy.

The purpose of this study is to evaluate the degree of PCBs contamination of wild brown trouts (Salmo trutta trutta L) caught in Marche Region rivers and to study the percentage contribution of the sum of the six indicators PCBs with respect to the sum of eighteen congeners in wild brown trouts. The determination of eighteen PCBs was made on the edible portion (fillets) of trouts by GC-ECD analysis. Fish samples were collected from fourteen rivers, selected to represent the fluvial pollution in the Marche Region. The total sum of eighteen congener concentrations was 8.2±0.9 ng/g wet weight. All the analysed samples showed a high variability of their congener profile even though the six PCBs indicators stood for 49.8% of the total PCBs. In the muscle of brown trout the Σ eighteen PCB and the Σ six PCB concentrations were not statistically correlated with the length and the body mass of specimens. Total PCB (Σ eighteen PCBs and Σ six PCBs) concentrations measured in the different sampling sites showed significant statistical differences among districts and, in the same district, among rivers (p<0.01). In particular, the lowest PCB levels (p<0.01) were detected in fish caught in Pesaro-Urbino Province rivers with the mean total PCB concentrations of 102.4±6.3 ng/g fat weight while the highest PCB levels were measured in specimens coming from Macerata Province rivers (1147.8±456.6 ng/g fat weight).