High levels of perfluorinated organic surfactants in fish are likely to be harmful to human health
High levels of perfluorinated organic surfactants, particularly perfluorooctane sulfonate (PFOS), have been detected in farmed trout from one of two pools examined near Arnsberg in studies by the regional authorities in North Rhine-Westphalia. Up to 1.180 microgram PFOS per gram fish flesh were measured. "Fish with high levels of this kind are not suitable for consumption", says BfR President Professor Dr. Dr. Andreas Hensel. "It is true that there is no acute threat to health even when a person has eaten normal amounts of this fish, i.e. 300 gram, once. However, as PFOS remains in the body for a long time, as little as possible should be ingested".
Perfluorinated surfactants (PS) are highly stable compounds that are used for instance in the processing of consumer articles, the manufacture of fluoropolymers, paper refining, fire-extinguishing agents and in cleaning products. The main representatives of this group are perfluorooctanoic acid (PFOA) und perfluorooctane sulfonate (PFOS). These two compounds have now been detected in fish in the Hochsauerland district.
The public authorities decided to examine fish from various ponds as elevated concentrations of PS had been observed in drinking water. Fish from one pond were found to have levels of between 0.4 microgram and more than 1 microgram PFOS per gram fish flesh. By contrast, the samples from another pond had less than 0.02 microgram PFOS per gram fish flesh.
PFOS is widespread in the environment as it is used in many areas of manufacturing. BfR does not have any completed risk assessments by national or international organisations at its disposal. Hence, it was not possible to establish a binding value for the tolerable daily intake of PFOS. BfR, therefore, suggests a provisional value of 0.1 microgram per kilogram body mass as the tolerable daily intake (TDI) to safeguard consumer protection. The Drinking Water Committee derived a similar value for drinking water. The TDI is the estimate of the amount of a substance which can be ingested daily over a lifetime by a human, irrespective of his age, without any significant risk to health.
However, the tolerable daily intake is already exhausted through the consumption of 300 g fish with a level of 0.02 microgram per gram fish flesh. Assuming that this amount is not consumed daily, concentrations of less than 0.02 microgram PFOS per gram fish are tolerable.