Polybrominated dibenzo-p-dioxins (PBDDs) and – dibenzofurans (PBDFs) in cod (Gadus morhua) liver-derived products from 1972 to 2017

Abstract

Literature data on the occurrence and prevalence of polybrominated dibenzo-p-dioxins (PBDDs) and polybrominated dibenzofurans (PBDFs) in foods including seafood are scarce. In this study, a number of cod-derived products including medicinal grade cod liver oils sourced from Northern Atlantic waters (Iceland, Norway) and the Baltic Sea (Poland) during 1972–2001 and canned cod liver sourced from the Baltic Sea in 2017, showed detectable levels of PBDFs: such as 2,3,8-TrBDF at 0.57 to 5.249 pg g−1 fat and 1,2,3,4,6,7,8-HpBDF at <0.018 to 0.302 pg g−1 fat. PBDDs were not detected in the cod liver oils. Canned cod liver products showed low levels of 2,3,7,8-TeBDD in the range <0.017 to 0.022 pg g−1 whole weight and 1,2,3,7,8-PeBDD at <0.03 to 0.039 pg g−1 whole weight. These concentrations were computed to yield upper bound toxic equivalences (TEQs) of 0.14 to 0.17 pg g−1 for the oils and 0.12 to 0.25 pg g−1 for the canned products (0.08 pg g−1 ww for both products). The resulting supplementary and dietary intakes are low (0.02 to 0.11 pg kg−1 bm day−1 for the oils and 0.07 to 0.17 pg kg−1 bm week−1 for the canned livers) in comparison to the recently expressed tolerable weekly intake of 2 pg kg−1 bm week−1. However, the intakes are underestimates, as due to a lack of analytical standards not all PBDD/F TEQ contributing congeners could be included. The PBDD/F TEQ contributes to the cumulative toxicity arising from other contaminants such as chlorinated dioxins and polychlorinated biphenyls.