By Pamela Ferdinand
A new study reveals that tiny particles from our laundry, food packaging, tires, personal care products and other items end up in West Coast seafood we commonly eat.
Researchers at Portland State University’s Applied Coastal Ecology Lab found the widespread presence of human-made materials (anthropogenic particles, or APs), including microplastics, in the edible tissue of five finfish and one shellfish species caught in Oregon waters: black rockfish, lingcod, Chinook salmon, Pacific herring, Pacific lamprey, and pink shrimp.
More than 1,800 particles were reported in muscle tissue across 180 of 182 individual seafood samples, according to the study, published Dec. 23, 2024, in Frontiers in Toxicology and led by Elise Granek, a Portland State University professor of environmental science and management.
Anthropogenic particles often contain pollutants that can leach into water and body tissues. Exposure to these chemicals raises the risk of various health issues, from hormone problems to cancer.
The samples included fish that are eaten both by marine predators and humans, which means concentrations of particles may increase (biomagnify) as they move up the food chain.
“It’s very concerning that microfibers appear to move from the gut into other tissues such as muscle,” says study co-author Susanne Brander, an associate professor of environmental and molecular toxicology at Oregon State University.
“This has wide implications for other organisms, potentially including humans, too.”
Particles in fish range from cotton fiber to polypropylene and fiberglass
Among the species sampled, pink shrimp, which feed by filtering water just below the surface, had the highest number of particles in their edible tissues.
A single pink shrimp that weighed 4.9 grams (equivalent to about five small paper clips) had the most: 36. Chinook salmon from a fishing vessel had the smallest amount and lowest concentration of APs, followed by black rockfish and lingcod.
The researchers also compared fish from research fishing boats with those from supermarkets and seafood vendors. They found indications that some retail market fish, including pink shrimp, may be exposed to additional particles through processing — for instance, plastic packaging meant to preserve seafood.
“Regardless of the source of seafood products, individuals containing APs were found to have at least [0.3 anthropogenic particles for every 10 grams] of edible tissue, signaling the need for policy and other interventions to regulate APs,” the researchers say.
They also reported:
- Fibers (1,466, or 82% of the total) were the most abundant particle type, followed by fragments (332, or 17%) and films (8, or less than 1%).
- The most common colors of particles were blue, black, and clear or white.
- The longest particle measured .142 inches (about as long as a quarter is thick).
- The widest particle measured 0.07 inches (roughly the width of a pencil tip).
The vast majority of the suspected APs (65%) were materials such as cellulose, cotton fiber and cellulose acetate, with about 17% of the materials fully synthetic, 9% semi-synthetic and 8% natural.
Synthetic and semi-synthetic material types included polyethylene terephthalate, polypropylene, low- and high-density polyethylene, polyethylene vinyl acetate, fiberglass and semi-synthetic cardboard.
The research team also found one instance of a common material used in marine rope, flame-retardant fabrics and military applications.
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Growing concerns about microplastics moving through the food chain
Scientists are increasingly documenting microplastic in commercial marine and freshwater species, raising health risks for animals and humans along with environmental justice concerns for people who rely on subsistence fishing or for whom seafood is an important food source.
Previous research by Granek, for instance, focused on microplastic concentrations in Pacific oysters and razor clams along the Oregon coast. On average, each oyster contained about 11 microplastic pieces, while each razor clam had about nine.
Nearly all were microfibers, which can come from clothing made from synthetic or natural materials and run-down fishing gear.
Another study conducted in Portugal showed that eating microplastic, including polyethylene and polyester, can lead to brain damage and harm to cells, tissues and DNA in wild fish.
The Portland State University researchers note that they had a small sample size of larger fish and collected fish only from the Oregon coast that had economic, historic or cultural importance in the state.
However, “when compared to other studies on microplastics in fish muscle tissue, our results are similar to the levels found in fish around the world,” they say.
“For producers and handlers of seafood, we recommend shifting to alternative packaging methods such as natural materials made from beeswax, starches, or sugars that will limit the introduction of APs into retail seafood,” the researchers say.
“For consumers, we recommend buying whole, local fish whenever possible to minimize APs introduced via plastic packaging.”
Still, international policies such as the ongoing global plastics treaty negotiations and its eventual enforcement are ultimately needed to address the problem at its current magnitude, they say.
“Unless we change our relationship with plastic and significantly reduce plastic production, we will continue to witness its negative impacts.”
Avoiding microplastics in fish can be challenging, but it can help to avoid shellfish from contaminated areas and check for information about the seafood source.
Originally published by U.S. Right to Know.
Pamela Ferdinand is an award-winning investigative journalist and former MIT Knight Science Journalism fellow who covers the commercial determinants of public health for U.S. Right to Know. She’s also a lecturer in journalism at Lake Forest College in Illinois.
