When plastics, like your grocery store bags, are set free into the environment, they break apart from exposure to sunlight, waves, abrasion, and bacteria. Large pieces break into smaller ones and ultimately into tiny particles that require special instruments to view. Microplastics are everywhere, in the air, the soil, and the seas. They are in our food and drinking water. So it is no surprise that they’re found in us as well.
While some microplastics pass through our digestive systems, not all do. They have been found in our major filtering organs: lungs, liver, spleen, and kidneys, and there doesn’t appear to be any way to clear them once they’re embedded. Disturbingly, Italian researchers have even discovered microplastic fragments in human placenta. In the 2020 study, they were able to identify the color of the fragments–blue, red, yellow, and violet in the placentas of normal full-term babies. No one knows yet if microplastics transit the placenta into the developing fetus.
What we do know is that nanoparticles can slip through the membrane of a human cell. And once there, they have an effect. Once in your cells, the chemicals in those plastics can disrupt hormones. A recent Norwegian study discovered metabolism-disrupting chemicals in common plastic items like yogurt containers, water bottles, and kitchen sponges that triggered fat development in cells, possibly contributing to obesity. It’s well known that plastic drink bottles shed microplastics when the cap is removed. If plastics can contribute to weight gain, maybe it’s time to rethink those plastic bottles!
Fortunately, here in Easton, your source for plastic-free water is as close as your tap. Easton Utilities Engineering Manager, Paul Moffett, says our town wells at 1,000-1200 feet in depth are “well protected from surface pollutants,” including microplastics. Alternating layers of clay and sand filter the water from our aquifers. Moffett says, “You could drink the water straight from the ground.”
Microplastics have settled onto the seafloor all around the world. They’ve even been found in the Mariana Trench, seven miles down, the deepest ocean floor in the world. Researchers who study seafood have found that mollusks that live on the seafloor—clams, mussels, and scallops—have the highest concentration of microplastic particles, four times higher than crustaceans—crabs, shrimp, lobsters—and 40 times higher than fish.
But before you tip over your steaming bowl of mussels, let’s ask what this might mean for those of us who regularly enjoy the fruits of the Chesapeake. University of Maryland’s Horn Point Laboratory post-doctoral researcher, Christine Knauss, studies plastics in our fisheries and recently completed a study on the effect of microplastics on oyster larvae.
While Knauss reassures us that there is no problem with eating our seafood, research into microplastics in our watershed is just beginning. When the federal government passed the Microbead-Free Waters Act in 2015 to ban microbeads from our personal care products, the Chesapeake definitely benefited, as at least one source of plastic pollutants has been taken out of the stream. “However, there were no microbead data in the Chesapeake Bay before 2015,” said Knauss. “The microbead ban was the first step towards reducing unnecessary plastics in products. These represent only a tiny fraction of microplastic pollution globally.”
Of course, the law can’t stop other sources of plastics from falling in or being thrown into the water. Last year, a container ship spilled 87 containers of “nurdles”—pea-sized plastic pellets for making other plastics–into the waters off Sri Lanka. It was the largest plastic spill in history and remains an ongoing ecological disaster. Ships containing these nurdles regularly ply the waters of the Gulf of Mexico to supply the plastic factories there. Fortunately, we are at lower risk here.
And while, yes, oysters and other mollusks are ingesting microplastics, they also filter them out. “Filter feeders are selective feeders and don’t ingest that much. Most field studies only find a small number of microplastics in adult oysters. Filter feeders like oysters and mussels will expel the plastic,” says Knauss. “We won’t get much by eating them.”
There’s even better news about fish. “You basically only eat the fillet of the fish, and unless you eat the digestive system, you’re not ingesting plastic,” says Krauss.
Still, while we can continue to enjoy our Chesapeake-based seafood, know that we are definitely ingesting plastic from our food and food packaging, that the chemicals in plastic break down and can cause health problems, and that there’s more of it all the time.
And there is that other thing. Says Knauss, “We breathe in far more microplastics than we eat. By two orders of magnitude.” That’s a hundred times more than we eat. Food for thought, indeed.
Plastic bags are a significant source of plastic pollution. Choose your reusable bags instead.
Marion O. Arnold is a member of Plastic-Free Easton
Brenda Meier says
Another informative article, Marion. Thank you for taking the time to so the research and to speak out.