Accumulation and distribution of polychlorinated dibenzo‐p‐dioxin, dibenzofuran, and polychlorinated biphenyl congeners in atlantic salmon (Salmo salar)

Abstract

Adult Atlantic salmon (Salmo salar) were fed on four diets containing polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) for 30 weeks. Lipid-normalized concentrations showed that all congeners were equally partitioned between whole-fish and fillet samples. Skinned fillet accumulated approximately 30% of the total PCDD/F and PCB content in fish. Accumulation efficiencies in whole fish were 43% for 2,3,7,8-chlorinated dibenzo-p-dioxins and dibenzofurans, 83% for dioxin-like PCBs, and 78% for other PCB congeners. Among PCDD/Fs, tetra- and pentachlorinated congeners were preferentially accumulated in salmon, whereas hepta- and octachlorinated dibenzo-p-dioxins were excreted in the feces. Substitution patterns that were associated with a preferential accumulation of PCBs in salmon included non-ortho substitution and tetrachlorination. Accumulation efficiencies and lipid-normalized biomagnification factors (BMFs) were not influenced by the PCDD/F and PCB concentrations of the diets. Biomagnification (BMF > 1) of tetra- and pentachlorinated dibenzo-p-dioxins and dibenzofurans and of all the PCBs was observed. Differences in the behavior of PCDD/F and PCB congeners resulted in a selective enrichment of the most toxic congeners in salmon.

Dietary uptake of dioxins (PCDD/PCDFs) and dioxin-like PCBs in Spanish aquacultured turbot (Psetta maxima)

“…Accumulation values reported by Isosaari et al (2004) in salmon were higher both for PCDD/Fs and PCBs: 57-64% of the total TEQ PCDD/Fs Table II. Dietary accumulation efficiencies and lipid-normalized biomagnification factors (BMF) (mean and standard deviation, SD, N ¼ 10) obtained for individual 2,3,7,8-chlorinated dibenzop-dioxins and dibenzofurans (PCDD/F) (definitions: see figure 1) and dioxin-like polychlorinated biphenyls (dl-PCBs) congeners obtained in farmed turbots of 1-2 years old.…”

“…Isosaari et al (2004) have obtained preferential accumulation of tetrachlorinated biphenyls in salmon, finding no significant differences in the accumulation efficiencies among PCBs with five to eight chlorines.…”

Sustainability, Security and Safety in the Feed-to-Fish Chain: Focus on Toxic Contamination

“…The mean transfer rate of PCDDs/Fs from commercial fish feed into the flesh of rainbow trout increased with the duration of exposure and ranged from 11.1 % at 6 months to 30.7 % at 19 months; there was a direct correlation between concentration in the lipid fraction of feed and that in fish flesh [70]. The feed-tissue transfer rate for DL-PCBs was higher than that of PCDDs/Fs in Atlantic salmon [71,72] and rainbow trout [73]. Interestingly, dioxins might accumulate also in fish eggs [70], a favoured delicacy for several consumer groups.…”

Safety assessment of seafood with respect to chemical pollutants in European Seas

“…They are released into the environment unintentionally and originate from different sources, mainly related to human activities (Baker, Hites 2000). Environmental contamination by PCDD/Fs is connected with their persistency (Isosaari et al 2004), biomagnification along trophic chains (Wan et al 2005), and toxicity to wildlife and humans (Van den Berg et al 2006). The average concentrations of PCDD/Fs and DL-PCBs in Baltic herring (11.5 ng WHO -TEQ kg -1 ) were found to be approximately 3.5 times greater than those recorded in herring from other marine regions.…”