PSU study finds drugs, toxins in Oregon oysters

PORTLAND, Ore. (KOIN) — Oyster lovers beware: A new Portland State University study revealed oysters native to the Pacific Northwest contain a cocktail of pharmaceuticals and other potentially harmful chemicals.

The study looked at native Olympia oysters in Coos and Netarts Bay. It found a variety of pain relievers, antibiotics, antihistamines, PCBs, mercury and pesticides in the shellfish, but the presence of chemicals appeared to shift with the seasons.

“The winter contains less compounds, but there is a spike in types and levels of compounds in the spring,” PSU associate professor Elise Granek told KOIN 6 News.

Granek has been studying native Olympia oysters since 2013. She says looking at their chemical contents over time is much more revealing than just looking at it once.

“If we take just a single snapshot in time it doesn’t tell the whole story,” Granek said. “We found that there are many different groups of chemicals from season to season.”

Chemicals found in the shellfish enter local bays through groundwater runoff and wastewater that’s discharged to inland rivers, eventually flowing into the ocean.

PSU researchers found levels of mercury in some oysters that were higher than populations studied from the Gulf of Mexico and the coast of France. Still, the university says levels of mercury in Olympia oysters are within state standards.

So, what does that mean for you? Researchers say they aren’t sure if consuming contaminated oysters or other seafood has an effect on human health.

Granek has applied for grants to continue the research and study whether eating contaminated seafood leads to measurable levels in the human bloodstream.