A recent study carried out by scientists in the US has claimed that eating just one serving of certain freshwater fish could equate to drinking water for a month contaminated with high levels of Perfluorooctane sulfonate (PFOS).

Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) are both part of a class of synthetic compounds called perfluoroalkyl substances (PFAS). Due to their resistance to water and lipids they are often found in products such as pesticides, adhesives, cleaning products, grease-proof food packaging and heat resistant tape.

However, they resist degradation when used and are increasingly detected as environmental pollutants in groundwater, surface water and soil. Some are also linked to negative effects on human health. According to the European Chemicals Agency (ECHA)  some PFASs are toxic for reproduction, can harm the unborn child, may cause cancer, and are suspected of interfering with the human hormonal system. This has led to many PFAS groups being banned globally or being restricted in the EU, with further restrictions of use currently being proposed.

Scientists at the Environmental Working Group (EWG) analysed data from more than 500 samples of fish filets collected in the US from 2013 to 2015 under monitoring programs by the EPA, the National Rivers and Streams Assessment and the Great Lakes Human Health Fish Fillet Tissue Study.

Results showed that the median level of total PFAS in fish filets was 9,500 nanograms per kilogram, with a median level of 11,800 nanograms per kilogram in the Great Lakes. This was 280 times greater than those detected in some commercially caught and sold fish.

“People who consume freshwater fish, especially those who catch and eat fish regularly, are at risk of alarming levels of PFAS in their bodies,” said David Andrews, Ph.D., EWG Senior Scientist and one of the study’s lead authors.

You can access the full report here