Estrogenic EDCs present in WWTP effluents are capable of feminizing fishes downstream of WWTP discharges as well as producing contraceptive-like effects. These changes have been documented in fish in Colorado streams, including Boulder Creek below the city of Boulder, Colorado, 75th Street WWTP effluent discharge. In 2001, researchers from the Department of Integrative Physiology, at the University of Colorado, Boulder, and the United States Geological Survey (USGS) in Boulder, began to examine fish in Colorado at points upstream and downstream of domestic WWTP points of effluent discharge. Specifically in Boulder Creek below the WWTP discharge, sex ratios for white suckers (Catostomus commersoni) were skewed toward females almost 5:1. In addition, researchers observed intersex fishes below the effluent discharges but never at upstream reference sites. In subsequent collections, contraceptive-like effects were identified on the ovaries and testes of fish at the sites downstream of the effluent discharge suggesting reduced fertility as compared to fish at the reference site.
Assessing Estrogenic Chemicals In Wastewater And Their Effects On Fish Reproduction – A Collaborative Effort Between Discharger And Researcher
During the past 70 years, humans have benefited from the production of a large array of chemicals including pesticides, pharmaceuticals, personal care product ingredients, cosmetics and plastics. Over this time period it is estimated that more than 80,000 different chemicals have been released in to the environment, with many released through the discharge of treated domestic wastewater treatment plant (WWTP) effluent. Exposure to some of these chemicals, specifically endocrine disrupting compounds (EDCs), elicits physiological responses in plants and animals, including fish.