Athlete’s foot meds found in oysters

A recent study detected endocrine disrupting pharmaceuticals and personal care product chemicals in oysters along the Oregon and Washington coast.

Study overview

To explore how aquatic pollution varies based on proximity to wastewater facilities, scientists placed one-week-old Pacific oysters at wastewater sites (not approved by state agencies as oyster growing sites) and near oyster aquaculture sites (approved for growing oysters) along the Oregon and Washington coastline. Nine and twelve months later, they collected the oysters, measured their health and size, and tested their tissues for pharmaceuticals and chemicals called alkylphenols, which are used in a variety of personal care and industrial products. Alkylphenols are endocrine disruptors that can alter the growth and reproduction of aquatic organisms.

Out of the 63 compounds tested, researchers found six in the oysters. The two pharmaceuticals detected in the oysters were miconazole, an over-the-counter drug for fungal infections like Athlete’s foot, and virginiamycin, a veterinary antibiotic used in livestock. As expected, the concentrations of pharmaceuticals were higher near the wastewater sites. The condition of the oysters was also poorer at wastewater sites compared to the sites near oyster farms.

Everyday products like detergents, cosmetics, soaps, and cleaners often contain alkylphenols as do forestry pesticide application mixtures. While detectable, the chemical levels were much lower than reported in other estuarine studies near more populated areas. Four types of alkylphenols were found in oysters from all the sites.

What this means

The very presence of these chemicals in oysters relatively far from wastewater sites and in sparsely populated coastal areas suggests that current wastewater treatment technology, stormwater mitigation strategies, and industrial use guidelines for alkylphenol use may not be sufficient. This could be bad news for aquatic animals, including shellfish.


Solutions for this kind of aquatic pollution include upgrading wastewater treatment plants and creating regulations that target the use of industrial products containing alkylphenols.

Individuals can also do their part by not flushing medications down sinks or toilets and instead using drop boxes available at many pharmacies. Additionally, look for the ‘EPA’s Safer Choice’ label when choosing personal care and home care products. If you see that label on cleaning products and detergents, that means that those products do not have alkylphenols, so they are better for the environment.

Journal Reference:  Amy L. Ehrhart, Elise F. Granek. Pharmaceuticals and alkylphenols in transplanted Pacific oysters (Crassostrea gigas): Spatial variation and growth effects. Marine Pollution Bulletin, 2021; 170: 112584 DOI: 10.1016/j.marpolbul.2021.112584

Posted by: EW