A report published by RIKILT – Institute of Food Safety and IMARES, both part of Wageningen UR – reveals that red eels from Dutch rivers are still highly contaminated. However, this is not applicable to eels from waters other than the large rivers, such as the IJsselmeer and the Frisian lakes.

The Contamination of red eels from the Dutch inland waterways (Verontreiniging rode aal Nederlandse binnenwateren) report contains the results from a study of eels caught between the period from 2004 to 2008 inclusive. The eels caught in the large rivers account for only a small fraction of the eels consumed in the Netherlands, namely approx. 5%. Most of the eels sold in the Netherlands originate from fish farms (95%). Earlier studies have revealed that fish-farm eels comply with the product standards.

A total of 65 samples were analysed for dioxins, PCBs and heavy metals. 54% of the samples contained levels of dioxins or dioxin-like PCBs above the accepted limit. Contamination was highest in eels from the Roer, Dordtsche Biesbosch, Amer, Hollands Diep and a variety of other locations in the large rivers. The Dutch lakes, such as the IJsselmeer, Gooimeer, Snekermeer, Loosdrechtse plassen and Markermeer, are cleaner. The levels of contamination of the eels caught in these waters are below the limit. No levels of heavy metals above the limits were encountered in any of the samples.

Dioxins and dioxin-like PCBs accumulate in the body and can cause serious health problems. The report also contains recommendations about the manner in which the quality of eels in regions that have already been cleaned or are yet to be cleaned needs to be tracked.

Note for the editors:
More information about this article is available from Jeannette Leenders, jeannette.leenders@wur.nl.