In King County, where Seattle is located, deaths involving pharmaceutical opioids continued to steadily decline to 94 in 2017, down from the peak of 153 in 2009, according to a 2017 drug trends report from University of Washington’s Alcohol & Drug Abuse Institute.
Experts believe the mussels are feeding on contaminants from human sewage that can’t be completely filtered by wastewater treatment plants. Traces of the chemotherapy drug Melphalan were also found in the mussels, according to the institute.
The amount of oxycodone found in mussels was 100 to 500 times less than a person would get in a normal therapeutic dose for humans, Lanksbury told KING. “You’d have to eat 150 pounds of mussels in that contaminated area to get a minimal dose,” she said.
“You wouldn’t want to collect (and eat) mussels from these urban bays,” Puget Sound Institute scientist Andy James said in a statement.
Mussels likely don’t metabolize the drug, the institute said, but it could be a concern for fish which are known to respond to opioids.
“Because we’re finding them in mussels, that means these chemicals are present in the water, and that means they’re likely affecting fish and other invertebrates in the water,” Lanksbury told KING.
A 2017 study from the University of Utah found that zebrafish, a small tropical fish, would willingly dose themselves with the opioid hydrocodone and can exhibit signs of withdrawal.
According to the Puget Sound Institute, scientists say salmon and other Puget Sound fish might have a similar response.