Dioxin-like polybrominated biphenyls (PBBs) and ortho-substituted PBBs in edible cod (Gadus morhua) liver oils and canned cod livers

Abstract

This study investigates the occurrence of polybrominated biphenyls (PBBs), a legacy flame retardant, in fishery products such as medicinal grade cod liver oils and canned liver products, sourced from the North Atlantic during 1972–2017. It also assesses the dietary and supplementary (the oils were commonly administered as dietary supplements to children and youth) intake of PBBs from these products. Summed ortho-PBB concentrations ranged from 770 to 1400 pg g−1 fat in the oils and from 99 to 240 pg g−1 whole weight in canned livers, with PBB-49, 52, 101 and 153 accounting for most of these levels. Among the more toxic non-ortho-PBBs, PBB-126 and PBB-169 were not detected, but PBB-77 concentrations ranged from 0.6 to 5.78 pg g−1 fat in the oils and 0.06–0.126 pg g−1 whole weight in canned livers. During 1972–1993, PBB contamination levels were similar for cod liver oils from the Baltic Sea and other North Atlantic regions, but over the timescale of the study, Baltic Sea products appear to show a decline in PBB concentrations. As PBB-77 was the only dioxin-like PBB detected in the samples, the corresponding supplementary (oils, 1972–2001) and dietary (cod liver from 2017) intakes were very low, at < 0.001 pg TEQ kg−1 bm d−1 (or < 0.01 pg TEQ kg−1 bm d−1 upper bound) for the sum of all the measured dioxin-like PBBs –four to six orders of magnitude lower than that arising from other dioxin-like contaminants that were shown to occur in these products, from earlier studies.