A Happy Medium? Antidepressants in Aquatic Systems

Wastewater treatment plants do a remarkable job at removing the bulk of chemicals from the waste stream. But recent USGS studies have shown that a wide range of pharmaceuticals and other human-caused waste compounds remain despite wastewater treatment and are discharged to receiving waters across North America. Antidepressants are a commonly used class of pharmaceuticals whose pharmacological effects may extend beyond humans to aquatic organisms present in surface water systems that receive treated wastewater discharge. Yet few methods exist to detect antidepressants in the environment, and their effects on aquatic organisms are only beginning to be understood. Recently, USGS researchers developed a method to study the distribution and fate of antidepressants and their breakdown products in aquatic environments, including municipal wastewater and surface water. Venlafaxine (Effexor) was the predominant antidepressant researchers found in wastewater and river-water samples from Colorado, Iowa, and Minnesota, though other antidepressants were found as well. Typical concentrations of individual antidepressants ranged from a few nanograms per liter to thousands of nanograms per liter (for Venalfaxine) in wastewater. This indicates that wastewater is a point source of antidepressants into the environment, at concentrations that may impact aquatic life. For more information, please contact Edward T. Furlong, USGS, at efurlong@usgs.gov or 303-236-3941; or Melissa Schultz, College of Wooster, Wooster, OH at mschultz@wooster.edu or 330-263-2645.