But that was not all, according to biologist Jennifer Lanksbury of the Washington Department of Fish and Wildlife. In the midst of a national opioid crisis, opioid could be the most prominent contaminant, but it could be the most worrying.
The mussels also contained four types of synthetic surfactants – the chemicals that are found in detergents and cleaners – seven types of antibiotics, five types of antidepressants, more than one antidiabetic and one chemotherapeutic.
Surfactants are particularly known to exert an estrogenic effect on organisms so that they affect the hormonal system of some animals in an estrogenic manner, such as feminizing male fish and reproducting female fish before they are ready, Lanksbury
Scientists have not investigated whether mussels are damaged by oxycodone. However, the presence of this drug in the mollusc speaks to the high numbers of people in the urban areas around the Puget Sound who take these medicines, Lanksbury said.
"Many of the pharmaceuticals are likely to come from our sewage They get the water that comes from our toilets and our homes and our hospitals and so we take those drugs and we then excrete them into our urine so they can get into the treatment plant way, "said Lanksbury. "Some people unfortunately flush their drugs to the bathroom, and that's a huge source of these drugs."
"The doses of oxycodone we found in shells are 100 to 500 times lower than for an adult male therapeutic dose," she said. "So you would have to eat 150 pounds of shellfish from these contaminated areas to get even a small dose, but only the fact that it's there tells us it's entering our waters, at least in urban areas."
The study's findings indicate that toxic contaminants are invading the food web of the larger Puget Sound, particularly along the shores near Seattle and other urban areas.
"What tells us is that some of these substances come from our wastewater treatment plants. They either have to control the sources better or try to reduce the exposure at Puget Sound," Lanksbury said.
The results are from a special small study. Every other year, she and her colleagues monitor fish and shellfish from the Puget Sound – specifically herring, English sole, chinook salmon and finally mussels.