Something that should go without saying is now considered very welcome good news, of which there is very little from the Arctic: Fish in the Beaufort and Chukchi Seas have apparently barely come into contact with mercury and PFAS, the so-called “forever chemicals”, so far.
Subsistence and recreational fishermen in Alaska can enjoy their catch with some peace of mind, at least in terms of exposure to PFAS, short for per- and polyfluoroalkyl substances, and mercury. This was the finding of a study that examined the pollution levels of important food fish from the Beaufort and Chukchi Seas along Alaska’s north coast.
The research team, consisting of scientists from the Wildlife Conservation Society, the University of Alaska Fairbanks, the U.S. National Park Service and the Native Village of Kotzebue, found traces of various chemicals, but significantly lower concentrations than in other Arctic regions.
PFASs are a variety of synthetic compounds that do not degrade in nature, which is why they are also called ” forever chemicals”. They accumulate in ecosystems and organisms worldwide and can cause serious health problems, including cancer and thyroid problems.
“Once these substances get into the water, they’re pretty much impossible to get out, and they can accumulate in the tissues of fish and wildlife,” says Kevin Fraley, a fisheries ecologist with the Wildlife Conservation Society (WCS) and lead author of the study, in a University of Alaska Fairbanks (UAF) press release. “In Alaska, we eat so many wild foods that it’s a pretty big deal to see how much of it is out there.”
As part of several long-term research projects at UAF and WCS, the research team studied the muscle tissue of fish species such as Dolly Varden char (Salvelinus malma), whitefish (Stenodus leucichthys), saffron cod (Eleginus gracilis) and other species relevant to subsistence fishers.
The fish came from nearshore waters near Prudhoe Bay and Kotzebue and were analysed for 24 PFAS compounds and mercury. The Dolly Varden char were almost free of chemicals in both areas, and in one sample from the Beaufort Sea, the researchers even found only traces of a single pollutant. Broad whitefish (Coregonus nasus), from the order Salmonidae, had the highest concentrations of a PFAS compound at 2.8 micrograms per kilogram. Mercury levels were also low.
Thus, all samples analysed were far below the limits recommended by other US states, which range from 9 to 47 micrograms per kilogram. Alaska has no health guidelines for PFAS contamination in fish.
Unfortunately, the low concentrations of pollutants in fish do not apply to the entire Arctic. In the Canadian and European Arctic, PFAS levels in fish have been found to exceed 30 micrograms per kilogram in some regions. These concentrations far exceed the European limits. The European Union has set the maximum value for the sum of all PFAS compounds in fish at 8 or 45 micrograms per kilogram, depending on the species. The EU sets a total tolerable weekly intake (TWI) of 4.4 nanogrammes per kilogramme of body weight, at which no health damage should occur in the case of lifelong intake. The EU sets a total tolerable weekly intake (TWI) of 4.4 nanogrammes per kilogramme of body weight, at which no health damage should occur in the case of lifelong intake.
PFAS and other pollutants spread from industrial regions worldwide through the atmosphere and rivers to polar regions and remote high mountain areas. They are used, for example, in fire-fighting foam, outdoor clothing and to-go cups.
Subsistence fishing makes a significant contribution to food security in Alaska. The study results published in the journal Environmental Toxicology and Chemistry are somewhat relieving, but they do not promise safety. There are around 10,000 different PFAS compounds worldwide and it cannot be ruled out that the fish in Alaska’s Arctic are not contaminated with other “forever chemicals”.
Julia Hager, PolarJournal
Featured image: Dolly Varden trout, photo: Bering Sea National Preserve.
Source Fraley, K.M., Hamman, C.R., Sutton, T.M., Robards, M.D., Jones, T. and Whiting, A. (2023), Per- and Polyfluoroalkyl Substances and Mercury in Arctic Alaska Coastal Fish of Subsistence Importance. Environ Toxicol Chem. https://doi.org/10.1002/etc.5717
For more information on PFAS, visit Hereon’s PFAS Explorer website: PFAS Explorer
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