On‐Site Exposure to Treated Wastewater Effluent Has Subtle Effects on Male Fathead Minnows and Pronounced Effects on Carp

This study tested the hypotheses that (1) exposure to treated Water Reclamation Plant (WRP) effluent will induce biological effects in exposed fish that are consistent with environmental estrogen (EE) exposure; and (2) seasonal differences in effluent composition will moderate biological effects. We conducted seven on‐site exposures using a mobile laboratory. Total estrogenicity of effluents was 10‐ to 20‐fold higher during spring than in fall. Common EEs including steroid estrogens, alkylphenols, and bisphenol‐A were ubiquitous. An unusual spike in total estrogenicity identified a combined sewer overflow event. Fathead minnows (Pimephales promelas) responded to exposure with subtle changes in vitellogenin concentrations and secondary sex characteristics. An opportunity to assess a common carp (Cyprinus carpio) population permanently sustained inside the Stickney WRP revealed pronounced exposure effects, but also the resilience of biological organisms even under long‐term exposure. In contrast to other studies, no histopathological changes were found. The mobile exposure laboratory proved capable of maintaining U.S. Environmental Protection Agency‐recommended exposure conditions while providing flexibility for rapid deployment at multiple sites with minimal operational disruption. Further studies using this platform hold promise to resolve the convoluted interactions between complex effluents and inherent biological complexity.     

Reconnaissance of Pharmaceuticals and Wastewater Indicators in Streambed Sediments of the Lower Columbia River Basin,Oregon and Washington

One by‐product of advances in modern chemistry is the accumulation of synthetic chemicals in the natural environment. These compounds include contaminants of emerging concern (CECs), some of which are endocrine disrupting compounds (EDCs) that can have detrimental reproductive effects. The role of sediments in accumulating these types of chemicals and acting as a source of exposure for aquatic organisms is not well understood. Here we present a small‐scale reconnaissance of CECs in bed sediments of the lower Columbia River and several tributaries and urban streams. Surficial bed sediment samples were collected from the Columbia River, the Willamette River, the Tualatin River, and several small urban creeks in Oregon. Thirty‐nine compounds were detected at concentrations ranging from <1 to >1,000 ng [g sediment]^?1 dry weight basis. Concentrations and frequencies of detection were higher in tributaries and small urban creeks than in the Columbia River mainstem, suggesting a higher risk of exposure to aquatic life in lower order streams. Ten known or suspected EDCs were detected during the study. At least one EDC was detected at 21 of 23 sites sampled; several EDCs were detected in sediment from most sites. This study is the first to document the occurrence of a large suite of CECs in the sediments of the Columbia River basin. A better understanding of the role of sediment in the fate and effects of emerging contaminants is needed.