SEATTLE — Feb. 29, 2016 — Wastewater flowing into Puget Sound contains some of the nation’s highest concentrations of emerging contaminants, according to a study published in the journal Environmental Pollution.
Scientists from NOAA Fisheries’ Northwest Fisheries Science Center and the University of Washington tested effluent from two wastewater treatment plants for 150 contaminants of emerging concern. They detected 81 of them, including pharmaceuticals such as the antidepressant fluoxetine (also known as Prozac) and the diabetes medication metformin, and antibacterial compounds from soap and industrial chemicals.
The researchers also examined juvenile Chinook salmon and Pacific staghorn sculpin, two species of fish native to Puget Sound. They found 42 of the emerging compounds in fish tissues, some of which were at levels that may be high enough to adversely affect their growth, reproduction or behavior.
“There’s also the problem of not knowing how these chemicals act in fish when they are found together as a mixture,” said James Meador, a NOAA Fisheries research scientist and lead author of the study. “Mixtures such as these may result in responses that occur at lower concentrations than single compounds alone.”
Noting that the two wastewater plants they examined discharged a total of 71 million liters per day, the researchers said it is possible that “a substantial load of potentially harmful chemicals are introduced into streams and nearshore marine waters daily.”
If the two facilities sampled in the study are representative of others around Puget Sound, the researchers calculated that nearly 300 pounds of the emerging contaminants likely enter Puget Sound every day.
“When you add it all up, you get millions of gallons of effluent discharging into these estuaries,” Meador said. “This is right in the area where juvenile salmon and other fish are feeding and growing.”
You can find the entire release here.