You might want to stick to East Coast oysters for a while: A new study from Portland State University researchers has found that the Olympia oysters, a prized and intensely flavorful species native to the Pacific Northwest, can contain "a cocktail of pharmaceuticals" that, at minimum, would probably require a pretty fierce mignonette to offset. Researchers tested Olympias in several Oregon bays, and the results turned up small amounts of potentially harmful chemicals that ranged from painkillers, antibiotics, and antihistamines to carcinogens, mercury, and pesticides. Experts say the drugs and toxins contaminate the bivalves after entering the bays from groundwater runoff, plant wastewater, and air pollution.
The study says the mercury level was also higher in these Olympias than it is in oysters from the Gulf of Mexico or France. Individually, the concentrations of all these unwanted chemicals (pharmaceuticals, mercury, whatever) fell within levels that Oregon deems safe — and, in fact, state officials released a statement saying that in order to ingest a "single dose of pharmaceuticals," you'd need to slurp down about 50,000 pounds of tainted Olympia oyster meat. But no one's sure what kind of curveball could come by consuming a "cocktail" of toxic chemicals all at once. Besides the human-health risks, the study goes on to add these pollutants "may affect the growth and reproduction of the oysters themselves — with possible widespread repercussions" for salmon and other marine species, since oysters play a key ecological role in their habitat by filtering water. Olympia oysters almost got harvested to extinction, but they've lately rebounded thanks to restoration efforts along the West Coast, so this discovery is a definite drag.