Two Dutch swimming sites closed over PFAS as dozens more receive health warnings
Authorities have closed two official swimming sites in the Netherlands and issued dozens of health warnings as summer temperatures draw more people to natural waters, NOS reports. A swimming ban has been imposed at De Betteld holiday park in Zelhem, Gelderland, where tests revealed “extremely high levels” of PFAS. At It Nannewiid near Oudehaske in Friesland, swimming has been declared unsafe because of nearby construction work.
Across the country, forty sites have tested positive for blue-green algae, also known as cyanobacteria, which can cause nausea, diarrhea and skin irritation. Swimmers can also develop swimmer’s itch, a rash triggered by parasites present in the water.
While swimming is not automatically forbidden at locations where blue-green algae are detected, experts strongly recommend caution. “Use common sense,” officials advise. Swimmers are urged to check the water’s appearance before entering. A visible scum layer or an intense green color should be treated as a clear warning to stay out.
Blue-green algae appear each year in Dutch waters. The bacteria thrive in the Netherlands due to the abundance of animals and human activity releasing nitrogen and carbon dioxide that promote growth.
At forty-two additional locations, swimming is explicitly discouraged because water quality fails to meet safety standards. In several areas, the presence of enterococci bacteria increases the risk of gastrointestinal complaints. Additional advisories have been issued for other contaminants. In Barendrecht, people swimming in the pond at the Vrijenburgbos may ingest excessive amounts of PFAS when exposure is combined with other sources.
The warnings are based on regular water measurements conducted during the swimming season at official sites. According to regional breakdowns, Noord-Holland has issued eight warnings and thirteen advisories against swimming. Zuid-Holland reported eight warnings and four advisories, while Friesland currently has three warnings, four advisories and one site under investigation. Utrecht has two advisories in place, and Gelderland has four warnings, three advisories and one swimming ban. Other provinces including Noord-Brabant, Groningen, Zeeland, Flevoland, Drenthe and Overijssel have also reported varying numbers of warnings and restrictions.
