Results of the monitoring of dioxin levels in food and feed
Environmentally persistent dioxins and dioxin-like compounds include 29 congeners of dioxins, furans and polychlorinated biphenyls (PCB) with similar toxic effects, their quantification commonly expressed as toxic equivalent units according to their varying potency. While the amount of those compounds in the environment has declined since the late 1970s, there is a continued concern because of their accumulation in the food chain, particularly in animal fat. In 2002 the European Commission prescribed a list of actions to further reduce the presence of dioxins and dioxin-like PCBs and later introduced action and maximum levels with random monitoring by Member States. A total of 7,270 samples collected in the period 1999-2008 from 19 Member States, Norway and Iceland were analysed in detail. Dioxin and furan congeners comprised between 30% and 74% of the total concentrations depending on food or feed group, while mono-ortho PCBs comprised between 15% and 45% of the dioxin-like PCBs. The highest mean levels of dioxins and dioxin-like PCBs in food expressed on fat basis were observed for ‘liver and products thereof from terrestrial animals’ and on whole weight basis for ‘fish liver and products thereof’. In feed the highest levels were found in ‘fish oil’. An overall 8% of the samples exceeded different maximum levels and a further 4% exceeded some action levels. However, some of these samples clearly originated from targeted sampling during specific contamination incidences and there were large variations between groups. Changing the basis for calculating toxic equivalent units to the new recommendations issued by WHO in 2005 will overall result in 14% lower values with the extent of the difference highly variable across food and feed groups. To ensure accurate assessments of the presence of dioxins and dioxin-like PCBs, continuous random testing of a sufficient number of samples in each food and feed group is recommended.