Factors influencing the intake of dioxins and dioxin-like PCBs via fish consumption in Germany

This study discusses the various factors which influence the intake of dioxins and dioxin-like PCBs (dl-PCBs) via fish consumption to support the requirements for additional information for an adequate estimation of consumer's exposure. Growing consumer preferences towards lean and aquaculture species have to be considered in future. The varying dioxin and dl-PCB levels of herring in relation to the geographical origin and the fishing season and their consequences for the estimation of the exposition are discussed. The levels in herring from different fishing grounds can vary by a factor of 8 between 0.43 and 3.04 ng WHO-PCDD/F-PCB-TEQ(2005)/kg wet weight. Increasing lipid content of the muscle meat during the feeding cycle of herring and mackerel leads to a "dilution effect" of contaminants based on lipid weight. Changes in the composition of feed for carnivorous species reduced the dioxin levels in farmed salmon and trout considerably between 1997 and 2004. Hence only recently taken data collections should be used for exposure estimation. Furthermore processing and household preparation can change the contaminant levels and should be taken into account.