...
By Melissa Fleur Afshar
Reporter
0
Share
Newsweek is a Trust Project member
See more of our trusted coverage when you search.Prefer Newsweek on Googleto see more of our trusted coverage when you search.
A link between eating certain imported fish and exposure to potentially toxic chemicals has been revealed by new research.
A team from the City University of Hong Kong (CityUHK), in collaboration with a group of international researchers, has published findings showing that commonly consumed fishes like salmon and cod are more likely to be contaminated with per- and polyfluoroalkyl substances, or PFAS—also known as forever chemicals—posing potential risks to our health.
Published in Science, the study analyzed edible marine fish that are widely traded and consumed around the world, including popular types like swordfish and tuna. Researchers found that imported fish brought into regions with relatively low environmental pollution contained significant levels of PFAS, raising concerns about food safety worldwide.
Read More on Science
“Elderly people, pregnant women, young children and individuals with chronic illnesses are more vulnerable to PFAS‑related risks and should therefore be especially careful when choosing seafood,” paper author and enivornmental scientist Kenneth Mei Yee Leung of CityUHK said in a statement.
“The public is also advised to maintain a balanced diet and limit their consumption of fish species known to have elevated PFAS levels to minimize potential health risks.”
...
PFAS are widely long-lasting chemicals found in a variety of industrial and consumer products—and even in water, air and soil, as a result of how hard they are to break down.
Previous studies have linked PFAS exposure to an increased risk of serious health issues, including cancer.
In their study, the researchers analyzed seawater-monitoring data from over 3,000 global sites over a 20 year period, while examining PFAS levels in 212 marine fish species. They were able to conclude that PFAS concentrations are higher in polluted areas and accumulate in predatory fish higher up the food chain.
Between 2010 and 2021, the median global PFAS level in fish was 0.34 nanograms per gram (ng/g), with Asia showing a higher median level at 1.03 ng/g. Some fish from Saudi Arabia and Thailand, meanwhile, had levels as high as 11.72 and 6.06 ng/g.
Trade data from 33 countries showed that fishes like cod, salmon, tuna and swordfish—which are often imported from Europe—contribute to significant PFAS exposure even in regions with relatively clean local waters.
For instance, in Italy, 11.71 percent of the fish consumed is imported from Sweden, but this contributes to more than 35 percent of Italians' PFAS intake.
Tests in Hong Kong into local fish intake found generally low PFAS levels, but several species, including blackspot threadfin and burrowing goby, had elevated concentrations.
The study also identified the key fish categories with higher PFAS risks: high-trophic-level predators like tuna and cod, as well as high-fat species like salmon and herring, and bottom-dwelling species like the burrowing goby.
Do you have a tip on a science story that Newsweek should be covering? Do you have a question about PFAS? Let us know via science@newsweek.com.
Reference
Qiu, W., Yang, G., Cao, L., Niu, S., Li, Y., Fang, D., Dong, Z., Magnuson, J. T., Schlenk, D., Leung, K. M. Y., Zheng, Y., Zeng, Z., Feng, L., Zhang, X., Zhang, Y., Fan, W., Huang, T., Ma, J., Wu, M., … Zheng, C. (2025). Risks of per- and polyfluoroalkyl substance exposure through marine fish consumption. Science, 390(6779), 1305–1309. https://doi.org/10.1126/science.adr0351
View 0 Comments
Submit Correction
View Editorial & AI Guidelines