University of Lethbridge researchers have secured $300,000 to dig into a question that touches nearly every resident: what happens to your brain when you swallow tiny bits of plastic from everyday food and water? Dr. Andrew Iwaniuk and Dr. Rob McDonald will lead the study, backed by a grant from the Natural Sciences and Engineering Research Council of Canada and Environment Canada.
The work, called ‘Neurobehavioural effects of chronic PET exposure,’ zeroes in on polyethylene terephthalate, or PET, one of the most common microplastics found in bottled water, clothing and food packaging. Over the next couple of years, the team will give rats water with PET levels matching what you would find in a typical bottle off the shelf, then test how it affects their learning, memory and fear responses.
“Despite how common microplastics have become in our environment, we still understand very little about how chronic ingestion of these particles affects our behaviour and brain health,” Iwaniuk said. The study will also examine the animals’ brain tissue for signs of neurological damage, filling a gap that has left scientists and the public guessing.
The Lethbridge project gained urgency after a 2026 Nature Health study found microplastics in nearly every human brain sample tested, 99.4 percent of diseased tissue and 100 percent of healthy tissue. PET was among the plastics identified, alongside polyethylene from bags and polyamide from textile fibers, pointing to multiple everyday sources.
McDonald, a pioneer in memory research and winner of the university’s 2025 Speaker Research Award, noted the stakes are high. “Compromised brain function can result in behavioural dysfunction, impaired physiological functions and increase the risk of diseases, like Alzheimer’s disease,” he said. By using long-term, low-dose exposure instead of large, one-time doses, the study aims to mirror real-life human intake more closely than past research.
The work is housed at the university’s Canadian Centre for Behavioural Neuroscience, a world-class facility with 16 principal investigators. It also aligns with Ottawa’s push for plastics science supporting zero plastic waste goals, adding a policy dimension to the findings. The University of Lethbridge currently ranks first in Canada for medical and science grants, according to Maclean’s 2026 ratings, underscoring its growing research footprint.
