It is one of the healthiest wild foods found in nature, the foundation of a significant Pacific Northwest economy, and ingrained in the diets and traditions of the local Indigenous population.
However, the pervasive plastic pollution in the world has also changed it.
Scientists in Oregon have discovered that salmon and a number of other well-known fish and seafood species in the Pacific Northwest have microplastics, which are particles smaller than five millimeters and are caused by the decomposition of plastic in the environment.
Chinook salmon, Pacific lamprey, lingcod, black rockfish, Pacific herring, and pink shrimp are among them.
According to a study by Portland State University, the microscopic particles were embedded in the edible tissue of those species, so when people eat them, they are undoubtedly ingesting the microplastics.
The study is another significant finding in an expanding body of research that indicates microplastics are found in soil, water, air, and the majority of our meals, as well as in the bodies of animals and humans, however it is still unknown whether these particles could be harmful to human health.
The presence of microplastics in these huge fin fish, particularly those that avoid inshore waters, was unexpected. Elise Granek, an ecologist and professor of environmental science and management at Portland State and one of the study’s authors, stated that seeing these quantities in them supports the notion that plastic pollution affects all places.
In Depoe Bay, Oregon, microplastic trash builds up on the shore.AP
COPY CONSUMERS
Granek’s research on the effects of medicines that leak from wastewater treatment plants into streams and the Pacific Ocean on the development and reproduction of marine creatures sparked her interest in microplastics.
Ten years ago, scientists were only now beginning to realize that the plastic that was piling up in the world’s seas, especially the Pacific Ocean garbage patch, was disintegrating and endangering animals, shellfish, and fin fish. The United States banned microbeads, which are microscopic plastic particles purposefully made for use in cosmetics, in order to stop more plastics from getting into waterways.
Granek’s team collected razor clams and Pacific oysters at 15 locations on Oregon coast beaches and estuaries in order to examine the prevalence of microbeads in marine species both before and after the ban took effect.
Granek stated, “We were pretty shocked.” Of the 280 people examined, microplastics were found in all but two of them. But fibers made up more than 99 percent of the microplastics we discovered. Microbeads accounted for only 0.2% of the contamination, indicating that they were not the primary source of the microplastics that were getting into our shellfish.
Equipped with this understanding, Granek sought to determine whether microplastics were also found in fish that resided further offshore, where human influence is less prevalent, as opposed to the beaches where they had previously collected shellfish samples.
She concentrated on fish and seafood, which are a major source of food for Oregonians as well as larger fish and mammals like seals.
Some of the fish and shellfish were collected by Granek’s crew on research vessels operated by the National Oceanic and Atmospheric Administration after they were newly caught. The Oregon Department of Fish and Wildlife gathered the lamprey samples.
However, in order to better replicate what customers could experience when purchasing pink shrimp, black rockfish, and lingcod, Granek also looked for products that had undergone processing and been packaged in plastic.
Before researchers cut out chunks of filet to simulate what humans would be eating, the fish were rinsed once more to simulate what human customers would do. The gutted herring and pink shrimp were used whole.
In contrast to other research on fish, this study focused on the edible meat of the animal rather than its intestines.
Every sample was digested in a potassium hydroxide base, which degrades tissue but not plastic. After filtering the remaining gooey soup, scientists were able to examine the microplastics under a microscope.
Granek collaborated with researchers at Oregon State University to determine the type of plastic by examining the distinct infrared absorption patterns of the plastic compounds using an infrared spectrometer.
microplastics in the laboratoryCanva
Films, fibers, and fragments
The research discovered 1,806 microplastic particles in 180 out of 182 distinct fish and shellfish samples, the majority of which were gathered in 2021 and 2022.
The most prevalent kind of microplastics discovered were fibers, which are normally shed by fleece vests and other clothing when they are laundered, followed by fragments and films. Plastic wraps and cigarette inserts are examples of films, but bigger pieces of plastic that have been broken down from things like plastic water bottles or shovels are known as fragments.
Although polyester and polypropylene fabrics, such as the PET recycled water bottles used in many luxury fleeces, are the usual source of fibers, plant-based cellulose blends like rayon also fall under this category because the threads are heavily altered with chemical additives.
According to Granek, the majority of what we’re witnessing is most likely from laundered clothes, towels, sheets, and other items.
The good news is that, out of all the creatures studied for the study, the chinook salmon had the lowest concentration of microplastics in its edible tissue, followed by lingcod and black rockfish.
The highest concentration of microplastics was observed in pink shrimp, with a single pink shrimp weighing.17 ounces containing a record 36 small particles. According to Granek, this is probably because shrimp, which consume microscopic animals like zooplankton, forage in regions where microplastics tend to gather and can confuse the plastic fragments for food.
The discovery supports the findings of other researchers that microplastics travel from the gut to other organs, muscles, and tissues.
Microplastics have lately been discovered in almost every human organ, including the placenta, lungs, human heart tissue, and the testes. They have even penetrated the brain itself across the blood-brain barrier.
According to Granek, researchers are still unsure of the exact method by which microplastics enter fish or human bodies. Because of their small size, fibers in particular might be able to get through the intestinal wall and other tissue, she said.
IMPACTS ON HEALTH UNCERTAIN
However, scientists are still unsure if microplastics can be harmful to humans.
Recent years have seen a few studies that highlight the possible link or correlation between high levels of microplastics and health issues, such as heart attacks, inflammatory gut diseases, and infertility. However, research is still in its early stages, with few studies having been published and those that have been replicated.
According to Linda Kahn, an assistant professor at New York University School of Medicine, there is very little proof that microplastics in the human body have any negative health impacts.
However, the fact that microplastics can move and have been discovered in almost all human organs and tissues is extremely alarming, according to Kahn, who researches the effects of chemical exposure on people.
She said that these are foreign particles and that an inflammatory reaction occurs whenever a foreign particle enters the body.
According to Kahn, inflammation can result in an overabundance of dangerous chemicals known as free radicals, which can disrupt DNA, cell membranes, or tissue.
According to her, the microplastics’ size and shape—whether they are rounded or sharp-edged, for instance—may also cause various effects or bodily movements.
The chemicals used to give plastics their flexibility, color, hardness, smoothness, and other qualities are a further source of worry. Scientists are already aware that certain of those additions, such the artificial compounds known as PFAS, which are frequently found in plastic food packaging, have negative health impacts. It’s possible that other chemicals are better bonded to the microplastic particles, which means they won’t hurt the body or circulate as much.
According to Kahn, microorganisms frequently reside on the surface of microplastics. According to her, the microbial colonies may be dangerous even though the plastic itself is safe.
The fact that science currently lacks a multi-dimensional measure of microplastics, which would inform researchers about their size, shape, chemical additives, and microorganisms, is a significant obstacle, according to Kahn.
Contamination of samples is also a common problem because everything from the air to the scientists clothes to the cup in which a sample is collected already contains the tiny particles.
In order to determine the level of microplastics in the environment, researchers Rosie Wood (left) and Becky Talbot gather water samples from the Clackamas River.Thanks to Elise Granek
Continue eating fish.
Granek advises against eliminating fish or shellfish from your diet out of extreme caution.
Fish is good for humans, loaded with beneficial Omega-3 fatty acids and vitamin D, she said. And microplastics have been found in virtually every food we eat, including beef, chicken and pork, sea salt, honey, craft beer and tea bags.
Not to mention, they re in the air we breathe, the water we drink and the soil we walk on so people would have to stop eating, breathing or drinking water if they wanted to eliminate them.
Microplastics are everywhere, so we re not saying that people should stop eating fish or shellfish. They re a really important food source, really high in nutritional value and important to Oregon s economy, Granek said.
What we are trying to highlight is that if we put plastics out into the environment, she said, they are going to end up back on our plates.
The best solution? Policies that reduce the production and use of plastics across the world, said Susanne Brander, an ecotoxicologist at Oregon State University and a co-author of the study.
A global approach is key because plastic made in one country often ends up in another, Brander said.
Negotiations over a global plastics treaty have been ongoing since 2022, with the goal of a production cap on plastic and limits on some of the chemical additives. But thenegotiations have stalledand it s unclear whether a treaty will materialize, given the re-election of Donald Trump and the increase in plastics production.
We feel like we have enough scientific evidence to say, we need to limit our production, we need to limit the impacts of plastics and the microplastics that fragment off of them, because it is harming not just the health of wildlife, but it s likely that it s harming our health too, Brander said.
But there are things people can do on other fronts.
Because scientists believe the laundering and drying of clothing may be a significant source of microplastics especially fibers laundry and dryer machine filters might be able to stem the flow.
Granek said her team is testing washing machine filters and dryer vent filters in households at the coast to see which are most effective and whether they re reducing the concentration of microplastics coming into local wastewater treatment plants.
Anew bill proposedthis session would require that all new washing machines sold in Oregon by 2030 have either an internal or external microfiber filter. A similar phase-in of filters has also been proposed in Australia.
Another billproposes to update Oregon s Sustainable Shopping Initiative, which in 2019 phased out plastic film grocery bags. The new bill would phase out thicker recyclable plastic bags at checkout as well as single-use plastic toiletries at hotels.
Less plastic in the environment would mean, of course, fewer microplastics, Granek said.
WHAT YOU CAN DO
To reduce exposure to microplastics:
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Buya laundry machine filter
. External filters are commercially available. They attach to the line that evacuates the water from your washing machine.
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Don t wash your fleece or other fleece-clothes after every use. And if you have to wash, do so in cold water and air dry. Every time you wash and dry, your machines spew tiny plastic fibers into the environment.
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Stay away from fast fashion. Cheap clothing sheds more. Higher-quality clothing will shed less in the long run. Buy used whenever possible.
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Choose to buy products made of silk or wool, rather than artificial fabrics.
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Avoid buying and using single-use plastics such as plastic water bottles, plastic grocery or produce bags and plastic food containers. Not only do they leach plastic and chemicals into your food, but they also will eventually break down into microplastics.
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Refrain from getting takeout in plastic containers, feeding babies with plastic bottles and storing food in plastic bowls or bags. Glass or stainless steel are safer.
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Don t microwave or cook in plastic. Heat increases the release of plastic chemicals.
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Vacuuming can help
reduce microplastic loads inside the home.
Gosia Wozniacka covers environmental justice, climate change, the clean energy transition and other environmental issues. Reach her [email protected] 971-421-3154.
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