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. KEY WORDS

Opinion of the Scientific Panel on contaminants in the food chain [CONTAM] related to the safety assessment of wild and farmed fish

“…The transfer rate for DL-PCBs was shown to be higher than that of PCDD/F in Atlantic salmon Lundebye et al, 2004) and rainbow trout (Isosaari et al, 2002). Table 4 shows dioxin and DL-PCBs contamination matter of Atlantic salmon due to feeding differently contaminated feed.…”

“…Using certain marine fish oils such as oil from Pacific Ocean species in fish feed can lead to reduced levels of dioxins and to a lesser degree dioxin-like PCBs in farmed Atlantic salmon Lundebye et al, 2004).…”

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.…”

The effect of organic and conventional production methods on sea bream growth, health and body composition: a field experiment

“…Industrial activity in the last century has led to increased levels of dioxins and the related dioxin-like PCBs in the environment, including the oceans, which has led to bioaccumulation in aquatic organisms (Froescheis et al 2000, Storelli et al 2007. Fish meal and especially fish oil from polluted areas have been linked with these pollutants, and hence there is the potential risk that farmed fish will be contaminated through their feed, with the consequent implications for the quality of the final product and human nutrition and health (Lundebye et al 2004, Bell et al 2005, Bethune et al 2006, Mozaffarian and Rimm 2006. The European Commission, recognising the potential risks originating from the accumulation of these substances, drastically reduced the permitted levels of dioxins in both animal feed and food for humans in 2000.…”