Scientists say seafood unfairly singled out in microplastics debate
Seafood has received disproportionate attention in discussions about microplastics, despite evidence showing that fish and shellfish are not the main source of human exposure, according to a new review published in Environmental Science & Technology Letters.
Researchers from Heriot-Watt University and international partners analysed scientific and media reports on plastic contamination in food and found that more than 70 percent of coverage has focused on seafood. The authors said this has contributed to the public perception that eating fish poses the greatest risk, prompting some consumers to reduce seafood consumption unnecessarily.
Professor Ted Henry from Heriot-Watt’s School of Energy, Geoscience, Infrastructure and Society said people are “far more exposed to microplastics from indoor air and dust” than from eating seafood.
“Seafood, including mussels, oysters and finfish such as salmon and cod, may contribute one to ten microplastic particles per day, which is consistent with other foods like salt, honey and chicken,” Henry said. “Ingestion from bottled water is estimated at ten to one hundred particles per day, and exposure from indoor air accounts for considerably higher exposure — one hundred to one thousand particles per day.”
He added that available evidence indicates plastic particles pass through the digestive tract and leave the body without causing harm. “While there are perceptions that toxic substances associated with plastic particles may pose health risks, evidence indicates concentrations are exceedingly low compared to other sources of exposure,” he said.
Henry attributed misconceptions about seafood to early research focus. “Seafood was one of the first foods tested for microplastics, partly because of assumptions that marine species would be most exposed and partly because it was easier to analyse,” he said. “That early focus created an impression that fish and shellfish are uniquely risky, but we now know other foods and drinks also contain microplastics.”
He added that seafood provides significant nutritional benefits and should be viewed in context. “Yes, microplastics have become ubiquitous in all settings, but there is no evidence that ingesting them is harmful to humans,” he said.
Asked whether he eats seafood, Henry replied: “Yes, several times a week and without any concern about the presence of plastic particles.”
The paper originated from the Microplastic and Seafood: Human Health Symposium held at Heriot-Watt University in September 2022. Funding for the symposium was provided by a consortium of seafood industry groups from the UK, USA and Australia. The research itself received no industry funding.
