Eating one freshwater fish taken in a US river or lake is the equivalent of drinking a month's worth of water contaminated with harmful "forever chemicals", according to new research released on Tuesday.

PFAS, or polyfluoroalkyl substances, were first developed in the 1940s to withstand water and heat and are now found in nonstick cookware, fabrics, fire suppression foams, and food packaging.

Since PFAS, or per- and polyfluoroalkyl compounds are indestructible, the contaminants have accumulated over time in the air, soil, lakes, rivers, food, drinking water, and even human bodies.

There has been an increase in calls for stronger regulation of PFAS, which has been related to a variety of major health problems, such as liver damage, high cholesterol, and decreased immunological responses, in addition to numerous types of cancer.

Between 2013 and 2015, a team of researchers examined over 500 samples from rivers and lakes around the United States to determine PFAS contamination in locally caught fish.

According to a new study published in the journal Environmental Research, the median amount of PFAS in the fish was 9,500 nanograms per kilogram.

PFOS was found in nearly three-quarters of the detected "forever chemicals", making it one of the most frequent and dangerous of the thousands of PFAS.

The researchers determined that eating only one freshwater fish was equivalent to drinking water with PFOS at 48 parts per trillion for a month.

The US Environmental Protection Agency reduced the limit of PFOS in drinking water that it considers acceptable to 0.02 parts per trillion last year.

According to the study, the overall PFAS level in freshwater fish was 278 times greater than that discovered in commercially sold fish.

David Andrews, a senior scientist at the non-profit Environmental Working Group which led the research, said, as quoted by AFP, that he grew up catching and eating fish.

"I can no longer look at a fish without thinking about PFAS contamination," said Andrews, one of the study's authors.

The findings were "particularly concerning due to the impact on disadvantaged communities that consume fish as a source protein or for social or cultural reasons," he stressed.

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"This research makes me incredibly angry because companies that made and used PFAS contaminated the globe and have not been held responsible."

Denmark, Germany, the Netherlands, Norway, and Sweden presented a request to the EU's European Chemicals Agency on Friday to ban PFAS.

According to the agency, the proposal is "one of the biggest in the EU's history" because the five countries discovered that PFAS were not effectively managed and that bloc-wide legislation was required.

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