Dietary uptake of dioxins (PCDD/PCDFs) and dioxin-like PCBs in Atlantic salmon (Salmo salar)

Abstract

Atlantic salmon (Salmo salar) were fed graded levels of dioxins (polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans) and dioxin-like polychlorinated biphenyls (DLPCBs) in their diets for 7 months. The dioxin and DLPCB concentrations in both fillet and whole body of salmon increased with increasing dietary exposure. DLPCBs transferred more efficiently from the feed to edible flesh of salmon than dioxins, and contributed a higher proportion to the total toxic equivalents (TEQ). At the end of the trial, the maximum concentrations of dioxins in fillet and whole fish were 1.9 and 2.3 pg WHO-TEQ g−1 fresh weight, respectively. Hence with this feeding period even with the most contaminated feed (4.9 pg WHO-TEQ g−1 dw) the dioxin concentrations in salmon did not exceed the maximum level set by the European Commission [4 pg WHO-TEQ g−1 (EC 2375/2001)]. The inclusion of DLPCBs in this study provides valuable information for forthcoming risk assessments and the future establishment of maximum limits for these compounds in feed and fish.