A month’s worth of freshwater fish caught in U.S. lakes and rivers has the same amount of “permanent” pollutants as drinking contaminated water called PFAS, a study says. In Switzerland, the rate of contamination is similar.
The published study reported that the average level of contamination was 9.5 micrograms per kilogram Environmental Research. Of all the contaminated samples, three-quarters were PFOS, one of the most common and harmful contaminants among the thousands that make up PFAS.
Eating one freshwater fish is equivalent to drinking contaminated water with 48 parts per billion of PFOA per month. According to the US Environmental Protection Agency (EPA), water is considered safe to drink if it contains no more than 0.2 parts per trillion of PFOS, according to its new recommendation.
Levels of PFAS found in wild-caught freshwater fish were found to be 278 times higher than those found in commercially farmed fish. “I can no longer look at a fish without thinking about PFAS contamination,” David Andrews, a scientist at the NGO Environmental Working Group who led the study and grew up fishing and eating fish, told AFP.
Switzerland is also concerned
Swiss lakes and rivers are not left out, especially Valais, where the five most polluted sites were identified by authorities last fall. The PFAS in question came from fire-fighting foams, which were mainly used at industrial sites, for example at Colombe’s former refinery (VS) site.
As explained by Yves Degoumois, Head of the Contaminated Sites, Soils and Groundwater Division of the Valais Environment Service, these substances are highly mobile and highly stable. “In the Rhône Valley, we have a very close groundwater table. These pollutants are highly mobile, they seep into the ground and are leached by water carried by the aquifer,” he explains to The Morning.
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“We find these substances in other surfaces. They are also found in fish with a very strong aggregation factor, so there is a higher concentration in fish than in water”, notes Yves Degoumois.
The ratio is higher in lakes and rivers than in fish farms. Traces of these persistent pollutants are still present through rainwater.
Valais is not an isolated case in Switzerland, but this example shows the difficulty of PFAS treatment. In polluted areas, they are blocked and the water is treated. But downstream of the site, other than monitoring drinking water and fish, there is no intervention.
>> Read More: Research results suggest that rainwater is not potable anywhere on earth
In everyday things
Perfluorinated compounds (PFCs) and polyfluoroalkyl compounds (PFAS), developed in the 1940s, are a family of synthetic chemical compounds comprising more than 4,700 molecules, some of which are suspected of being harmful to health. They owe their nickname to their extremely long life cycle.
With non-stick, waterproof and heat-resistant properties, these materials are used in many industrial sectors and in everyday products: Teflon materials, food packaging, some textiles, etc.
But the persistent nature of these PFAS, per- and polyfluoroalkyles, indicates that they accumulate over time in the air, soil, water of lakes and rivers, food, and even in the human body.
There have been increasing calls for stricter restrictions on the use of PFAS, which are harmful to health with liver effects, high cholesterol, reduced immunity and several forms of cancer. The researchers wanted to measure pollution in freshwater fish by analyzing 500 samples taken from US lakes and rivers between 2013 and 2015.
Radio subject: Alexandra Richard
Web Adaptation: jfe
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