Oxycodone and other addictive pharmaceuticals are already a fixture in doctors’ prescriptions, illicit drug deals, national news coverage and even in the veins of physically-dependent Americans. Now, the aggressively marketed drug considered largely responsible for the opioid epidemic that claims more lives with each passing year is starting to show up in our seafood, too.
The opioid was one among several potentially worrisome pharmaceuticals found to be entering Seattle-area waterways and then absorbed by marine species like mussels and juvenile Chinook salmon in a biennial water quality analysis conducted by the Washington Department of Fish and Wildlife (WDFW) and Puget Sound Institute (PSI). In a nutshell, the Puget Sound Mussel Monitoring Program tracks pollution levels by placing mussels at 18 test sites throughout the waterway, then dragging them up months later to see what contaminants the filter-feeding shellfish have absorbed in the interim.
“We had quite a few new antibiotics showing up,” says PSI research scientist Andy James, who assisted in the study. He quickly added, “Almost none of this stuff is a human health problem yet. You can go out and eat mussels, and the concentrations are low enough it wouldn’t matter. But we’re worried some of it may affect the animals in a certain way.”
This year’s edition was both the first to test for and first to detect oxycodone in filter-feeding shellfish. Thankfully, it was present at such low levels that you’d have to eat about a hundred pounds of mussels to obtain the equivalent of a standard human dose. Further, the highly addictive drug was only ingested by the shellfish at three of the 18 test sites, all far removed from commercial shellfish beds and near urban areas, where the remnants of pharmaceuticals are often discharged from wastewater treatment plants.
While mussels don’t metabolize oxycodone and are thus immune to its habit-forming effects, the researchers worry how it might impact fish populations, for whom it’s been found to have an addictive potential similar to humans. “The main worry about these things is that it’s chipping away at fish’s ability to reproduce,” says James. “With so many other factors driving fish and salmon populations, it makes it that much worse.”
“[Oxycodone] … the aggressively marketed drug considered largely responsible for the opioid epidemic that claims more American lives with each passing year is starting to show up in our seafood …”
James and other participating scientists interviewed on the study are apt to shift focus away from oxycodone onto other pharmaceuticals detected that have less name recognition but may pose an even greater risk to marine species, like the increasingly common chemotherapy drug Melphalan. “They’ve found it can cause inheritable mutations,” says James. “If you expose a fish in a lab, it will affect their reproduction and the quality of their offspring, sending mutations down to the baby fish.”
Melphalan, which has also been absorbed by the test mussels in low quantities, may be used to treat cancer, but is itself a carcinogen so powerful that parents taking it must worry about transmitting its deleterious effects to their children via sweat. Like many pharmaceuticals, it’s only metabolized partially by the body before being excreted, meaning the remainder is left to run through plumbing and into our waterways. This, combined with hospitals flushing raw drugs and homeless shelters washing remnants down the storm drain, helps explain the newfound presence of Melphalan and other prescription chemicals in Puget Sound.
“It’s all based on human consumption,” explains James. “We take a pill and it’s only halfway metabolized, so it runs through the system and out to Puget Sound. It’s very diffuse, but when you get a lot of people, it adds up.”
At present there’s little insight into how Melphalan might affect shellfish or other species differently than humans, so PSI is trying to assess what impact it and other untested pharmaceuticals will have as they ascend the food chain in marine ecosystems at ever-increasing levels in order to identify the chemicals causing problems. PSI will then be able to recommend actions to safeguard our waterways without sacrificing public health.
“The complicated part is, there’s a definite benefit to this chemo drug being used,” says James. “It’s showing up in low levels now, so do the low levels matter? If we decide that the drug is worth having around but still causing problems, we have to focus on [how we] treat wastewater.”
The technology to treat wastewater and screen out potentially harmful pharmaceutical chemicals exists, but, as with most combative efforts against the opioid crisis, the public funding required to invest in new and improved treatment just isn’t there — in Seattle or elsewhere throughout the nation. Until it is, average citizens can help alleviate the damage wrought on marine habitats by disposing of their own medications properly, as well as educating friends and family on alternatives to oxycodone and other potentially habit-forming prescriptions.