From Dr. Mercola:
Fish was once one of the healthiest food sources on the planet, but as waterways have become increasingly polluted by industry and pharmaceuticals, so, too, have the creatures that live in them.
Discharge from wastewater treatment plants is turning out to be an alarming source of this pollution, particularly since the plants are not always designed to remove pharmaceuticals and chemicals in personal care products.
The result is that once they get flushed down the drain (or toilet), they end up in local waterways.
Puget Sound Fish at Risk From Wastewater Contaminants
A study by the National Oceanic and Atmospheric Administration (NOAA) Northwest Fisheries Science Center analyzed wastewater effluent for 150 contaminants and found 81 present in the samples.1
Pharmaceuticals, including the antidepressant Prozac, the diabetes medication metformin, cholesterol-lowering statin drugs and triclosan, an antibacterial compound found in soap and personal care products, were found in the wastewater flowing into Washington’s Puget Sound, as well as in the Sound’s water and fish.
According to the researchers:2
“Collectively, we detected 81 analytes in effluent, 25 analytes in estuary water, and 42 analytes in fish tissue.
A number of compounds, including sertraline, triclosan, estrone, fluoxetine, metformin, and nonylphenol were detected in water and tissue at concentrations that may cause adverse effects in fish.”
Nearly 30 of the contaminants were detected in fish but not in surrounding waters, which suggests the toxins are bioaccumulating in their flesh.
Salmon on Drugs
Salmon are regarded as an indicator species, which means they serve as a measure of environmental conditions. The researchers examined juvenile Chinook salmon and Pacific staghorn sculpin, both of which are native to Puget Sound.
More than 40 contaminants were detected in their tissues and some, namely Prozac, metformin and triclosan, were found at levels that could harm their growth, reproduction and behavior.
No one knows how this chemical cocktail will affect fish, especially since they’re being exposed to a mixture of drugs at once, but it may mean adverse effects will occur at even lower concentrations.
The study did not look into the health effects to humans of eating these contaminated fish, but the fish themselves could likely show some issues. Past research has found, for instance, that dilute concentrations of psychiatric drugs alter the behavior of fish.
Exposure to Pharmaceuticals Disrupts Wild Fish Behavior
Wild perch exposed to anxiety drugs displayed increased activity, reduced sociality and higher feeding rates,3 which could disrupt the natural balance of their surrounding ecosystem.
The featured study researchers further explained that while the contaminants may not kill fish outright, they’re likely to have serious, lasting consequences:4
“A noteworthy outcome of the present study is the occurrence of several compounds in water and tissue that have the potential to affect fish growth, behavior, reproduction, immune function, and antibiotic resistance.
One recent review provides a summary of studies on the effects of endocrine disruptors on immune system in fish (Milla et al., 2011). Many of these