Fluorinated, brominated and chlorinated contaminants in fish for human consumption Methods and measurements

Fish is an important part of our food. In addition to its general nutritional value fish contains essential nutrients like omega-3 and omega-6 fatty acids, which are believed to be beneficial for our health. Fish is also an important dietary source of selenium. Unfortunately, several contaminants are present in fish, such as heavy metals and organohalogen contaminants. Well-known examples of the latter are polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins and –furans (dioxins) and DDT. Production of PCBs and DDT has started before World War II and were used in industrial and consumer applications as well as in agriculture. PCBs and DDT have entered the environment during production, product formulation, application and disposal or (for dioxins) as a result of combustion processes or as a by-product of chemical synthesis (chapter 1). Environmental residues of these xenobiotic compounds have been found since the late 1960s. Extensive research is carried out to these contaminants since then. This showed that these contaminants are persistent, bioaccumulate, have adverse effects and are transported globally over large distances. They are therefore qualified as persistent organic pollutants (POPs) in the framework of the Stockholm Convention. More recently, new contaminants were found in fish, such as polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD) and perfluorinated compounds (PFCs). These compounds are still being produced for application in consumer products and industrial processes. There is toxicological concern on these contaminants. The toxicity of dioxins and dioxin-like (dl)-PCBs received much attention, and these are among the most toxic substances known. Non-dioxin-like (ndl) PCBs are less toxic, although they can cause neurotoxic effects. The toxicity of PFCs, PBDEs and HBCD is under investigation, and their complete toxic profile is not yet elucidated, although several adverse effects of these compounds were reported. Through the consumption of fish, these contaminants are ingested and may potentially harm consumer's health. Several studies showed that fish is an important contributor to the dietary exposure to e.g. dioxins, PCBs, organochlorine pesticides (OCPs) and PBDEs. Information on the dietary exposure to HBCD and PFCs is urgently needed to allow adequate exposure