Image: Oregon State University via Wikimedia Commons

by Amy Lupica, ODP Staff Writer

A new study has found that microplastic accumulation may be worse than previously thought and could carry with it the threat of disease. Microplastics could present health risks to the entire food chain, the study said, including to humans. As the world is grappling with the accumulation of single-use plastics during the pandemic, the study is a reminder that we must be far more diligent about ensuring our waste isn’t making it into nature.

Already it’s believed that humans ingest a credit card worth of microplastic each week and we don’t know much about how this affects our health.

Why This Matters: Microplastics and other chemicals like PFAS are now ubiquitous. Plastics and forever chemicals can be found in nearly every ecosystem, from the top of Mt. Everest to the bottom of the Mariana Trench. Like other forms of pollution, microplastics don’t stay where they’re deposited initially. They migrate in water, air, and soil and end up in the food we eat and the water we drink.

PFAS and microplastics (which are made of petrochemicals) have been linked to nervous system problems, hearing loss, cancer, reduced fertility, and hormonal imbalances. Now, scientists confirm that the number of harmful microplastics making their way up the food chain may be far more than previously thought.

The Food Chain: Researchers at the University of Portsmouth noticed that many microplastics studies in coastal waters failed to account for common nutrient and bacterial buildup on plastic beads and particles.

• Researchers coated microplastics with an E.coli biofilm to observe uptake rates by oysters. They found that oysters contained ten times more microplastics when exposed to biofilm-coated beads.
• This may be because the beads were more food-like to the oysters, but one thing is sure: the uptake impacted the creatures’ overall health.

“What we’ve discovered is that microplastic really is the Trojan Horse of the marine world,” said Dr. Joanne Preston, Reader in Marine Ecology and Evolution at the University of Portsmouth. “We know microplastics can be the mechanism by which bacteria are concentrated in coastal waters, and this shows that they are more readily taken up by shellfish and can be transferred to humans or other marine life.”

Researchers say that this study is only the start of a broader conversation about microplastics and PFAS in our oceans and environment. “This opens the door for more research on environmentally relevant studies of the long-term impacts of biofilm coated microplastics on a wider range of marine life,” said Preston. “We also need to study the transfer of microbes up the food chain via plastics in much greater detail.” Other researchers agree; Professor Steve Fletcher, Director of the University’s Revolution Plastics initiative, said, “the findings in this research give us further insight into the potential harm microplastics are having on the food chain…It is clear that further study is urgently needed.”