A recent study by chemists in French-speaking Switzerland has shown that regulatory limits for PFAS are exceeded in certain species of fish living in Lake Geneva.
These findings, based on a small sample of fish, are now being questioned by professional fishermen who fear damage to their image and a drop in demand from their customers. Despite the small number of fish analyzed, it seems surprising that certain species of fish living in the same environment contain higher concentrations of PFAS (particularly PFOS) than others.
A closer look at the DFI Ordinance (OCont) reveals that the maximum PFOS levels are not the same for all species. The limit is set at 7 micrograms per kilogram for trout and pike and 35 micrograms per kilogram for perch, char, whitefish, and zander. It is therefore not surprising that trout and pike exceed the limits, which are five times lower than those for other species!
Why this difference between species?
The specialists at the Federal Department of Home Affairs will certainly be able to provide us with more details!
Our regional television station Canal9 has produced an interesting report on the subject.
Fishermen in the Valais region are certainly wondering whether the trout they consume also contain PFAS in proportions exceeding the regulatory limits. Analyses were carried out in 2022 in various lakes and rivers in the canton, and some of these were closed to fishing (Stockalper Canal, Mangettes Canal, Gouille des Mangettes, etc.). In the other waters, the levels found in the fish analyzed were below the limit values. In addition, the trout used for measurement are sourced from farms that are regularly inspected by the cantonal health authorities.
You can therefore continue to catch trout in our Valais waters and enjoy eating them!
Happy Easter!
