A team of researchers from the University of Toronto (UT) recently reported that following six years of research, 212 fish species they hauled and inspected from a harbor in western Lake Ontario all contained synthetic particles that potentially can harm humans if ingested by eating the fish, according to a report from TVOntario (TVO).
One of the fish was a brown bullhead captured from Hamilton Harbor, located southwest of Toronto. That bullhead set a record for the most synthetic particles ever discovered in a fish, with 915. It’s raising new concerns about human health.
“I’ve been studying microplastics for a long time, and this is the study that blew me away,” Chelsea Rochman, a co-author of the study, told TVO.
The brown bullhead was one of 212 specimens examined during six years of research on plastics pollution led by Keenan Munno at UT’s Rochman Lab. The study was published in Conservation Biology last summer. Munno and her team discovered synthetic particles in each specimen. In the bullhead, some of the smallest particles, called nanoplastics, had migrated from its digestive system to its skeletal muscles—fillets, that may be sold in grocery stores.
Scientists say such discoveries underscore the need for more research into nanoplastics and their effects on ecosystems and humans—and for halting Great Lakes pollution.
TVO’s story revealed that nanoplastics carry great potential for harm, as they travel more freely and pose a higher risk of cellular interference. Researchers say because of their microscopic size and relatively large surface area, nanoplastics interact differently with cells than microplastics do. When ingested, TVO continues, nanoplastics can permeate intestinal cell walls and pass from the digestive tract into the bloodstream. Instead of being excreted following consumption, they can accumulate in such vital organs as the gut, liver, kidney, and brain. The accumulation of synthetic particles in these key areas has been linked to inflammation, oxidative stress, and immune response in animal studies.
“[Nanoplastics] might have much broader, subtler effects on development of diseases and on how these diseases differentiate, how they get worse or get better,” explained Daniel Cyr, a Montreal researcher. “These have consequences to neuroscience, neurodegenerative diseases, female reproduction, and in the male reproductive tract.”
The accumulation of nanoplastics in parts of the human body causes inflammation at tissue barriers and may damage or alter these barriers in ways that could contribute to the body’s immune responses, Cyr told TVO. According to Cyr, nanoplastics can interact with the blood-brain barrier, disrupting cellular function.