Mussels are the latest organisms affected by the human opioid crisis.
Researchers at the Washington State Department of Fish and Wildlife have found traces of oxycodone in mussels in Puget Sound – which is about 200 kilometres south of the Canadian border.
The researchers say the mussels are filter feeders, meaning they absorb contaminants from the surrounding water into their tissue.
“It seems like the prescriptions for opioids are high enough that it’s starting to come out in the waters here at least in the really you know, dense urban corridors,” Washington Department of Fish and Wildlife biologist Jennifer Lanksbury told Global News.
The opioid epidemic is raging on in the U.S. and Canada. In 2016, there were nearly 2,946 opioid-related deaths, and in the first half of 2017, there were 2,923, according to Statistics Canada.
Lanksbury said the opioids likely entered the water through human waste, either through urine after ingesting the drugs, or in higher concentrations when people flush pills down the toilet.
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The mussels were found in three out of 18 test sites from a highly urbanized area. They were collected in 2013; Lanksbury said that her team was unable to test for pharmaceuticals before this year due to money constraints.
Other substances were also found in the mussels, including antidepressants, antibiotics and detergents. The chemotherapy drug Melphalan was also found in the shellfish, in “levels where we might want to look at biological impacts,” Puget Sound Institute researcher Andy James said in a blog post.
Canadian researchers say similar contaminants are also found in waters in Canada.
While the mussels themselves likely don’t metabolize the drug – and therefore shouldn’t be affected by it – the fact that it’s there raises concerns about the fish in the area.
Lanksbury said the containments can have negative impacts on fish and shellfish in the surrounding areas.
“Things like, they can affect the growth of organisms, their hormone systems, their ability to reproduce,” she explained.
“In juvenile Chinook salmon, we found doses of antidepressants and heart medications that are at levels that we would maybe start to see negative effects on the survival of those juvenile Chinook salmon,” she said.
She also explained that other research in Utah has shown zebrafish will dose themselves with oxycodone.
At this point, the levels are low enough that the drugs wouldn’t have effects on humans.
Lanksbury said the research couldn’t have been done without an army of citizen science volunteers who put the mussels out in low tide during the winter, and retrieved them three months later.