Various types of fish, crustaceans and shellfish from the Western Scheldt contain such high concentrations of PFAS that the National Institute for Public Health and the Environment (RIVM) advises eating them “as little as possible”. The institute has calculated how many people can eat for various species without ingesting excessive doses of harmful chemicals. For example, a portion of bone can only be eaten twice a year without exceeding limit values.
The RIVM reminds us that on average, the Dutch ingest too high concentrations of PFAS through their food and drinking water. The institute noted this in a report last year. Therefore, it is “important to increase the intake of PFAS as little as possible,” the researchers now write.
PFAS are man-made and barely biodegradable. The substances can be found in many places due to widespread use and discharges. From a certain exposure they can cause health damage. Certain types of PFAS can harm young children’s immune systems. Exposure above a certain level also increases the risk of cancer, liver damage and high cholesterol. The Western Scheldt contains PFAS, among other things, because chemical group 3M in Zwijndrecht, Belgium, discharged it into the Scheldt for years.
The RIVM focuses the warning specifically on hobby fishermen, because they mainly catch fish in the area. “Since it is plausible that people who get these products from the Western Scheldt are enthusiasts, it is assumed that they will consume large portions,” the researchers continued. So they better watch out for that. There is hardly any commercial fishing on the polluted Western Scheldt. Shrimp fishermen who were active there recently decided to avoid the estuary as a precaution.
According to the study, if people would not ingest other products with PFAS, they could eat sea bass from the Western Scheldt one to six times a year. This bandwidth is quite large, because the quantities involved are very small and this entails statistical uncertainty. A serving of shrimp more than five to six times a year could lead to overexposure. The margin is larger for oysters and mussels: RIVM calculates twice a week in the best case scenario and a maximum of seven times a year in the worst case. Professional mussel fishermen are not active in the area. No too high PFAS values were measured in sea vegetable sea lavender.
RIVM recently published a first study into swimming in the Western Scheldt. The outcome was quite reassuring. PFAS concentrations measured at a site believed to be more polluted than the official swimming sites were not too high. Further investigation will follow at three swimming locations.