Department of Environmental Science and Center for Reservoir and Aquatic Systems Research, Baylor University, Waco, TX, 76798, USA.
Carollo Engineers, Inc., Midvale, UT, 84047, USA.
Environ Pollut. 2020 Oct;265(Pt B):115122. doi: 10.1016/j.envpol.2020.115122. Epub 2020 Jun 27.
Current practices employed by most wastewater treatment plants (WWTP) are unable to completely remove endocrine disrupting compounds (EDCs) from reclaimed waters, and consistently discharge these substances to receiving systems. Effluent-dominated and dependent surface waters, especially during low instream flows, can increase exposure and risks to aquatic organisms due to adverse biological effects associated with EDCs. Given the ecological implications that may arise from exposure to such compounds, the present a multi-approach study examined spatio-temporal estrogenic potential of wastewater effluent to fish in East Canyon Creek (ECC), Utah, USA, a unique urban river with instream flows seasonally influenced by snowmelt. Juvenile rainbow trout (Oncorhynchus mykiss) were caged at different upstream and downstream sites from an effluent discharge during the summer and fall seasons. In the summer, where approximately 50% of the streamflow was dominated by effluent, fish from the upstream and a downstream site, located 13 miles away from the effluent discharge, presented significantly elevated concentrations of plasma vitellogenin (VTG). Similarly, significantly high 17β-estradiol to 11-ketotestosterone ratios were measured in the summer across all sites and time points, compared to the fall. In the laboratory, juvenile fish and primary hepatocytes were exposed to concentrated effluent and surface water samples. Quantification of VTG, although in significantly lower levels, resembled response patterns observed in fish from the field study. Furthermore, analytical quantification of common EDCs in wastewater revealed the presence of estriol and estrone, though these did not appear to be related to the observed biological responses, as these were more significant in sites were no EDCs were detected. These combined observations suggest potential estrogenicity for fish in ECC under continuous exposures and highlight the advantages of following weight-of-evidence (WoE) approaches for environmental monitoring, as targeted analytically-based assessments may or may not support the identification of causative contaminants for adverse biological effects.
当前，大多数废水处理厂（WWTP）采用的方法无法完全去除再生水中的内分泌干扰化合物（EDCs），并持续将这些物质排放到接收系统中。在低流量期间，以废水为主导且依赖于废水的地表水中，由于与 EDC 相关的不利生物效应，水生生物的暴露和风险会增加。鉴于接触此类化合物可能带来的生态影响，本多方法研究考察了美国犹他州东峡谷溪（ECC）废水中的雌激素潜力对鱼类的影响，ECC 是一条独特的城市河流，其流量受融雪季节性影响。在夏季和秋季，将幼虹鳟（Oncorhynchus mykiss）养在远离废水排放口的不同上游和下游位置的笼子里。在夏季，大约 50%的流量由废水主导，来自上游和下游的鱼类（距离废水排放口 13 英里）的血浆卵黄蛋白原（VTG）浓度显著升高。同样，与秋季相比，在所有地点和时间点，夏季的 17β-雌二醇与 11-酮睾酮比值均显著升高。在实验室中，将幼鱼和原代肝细胞暴露于浓缩废水和地表水样品中。尽管在较低的水平下进行了定量，但 VTG 的定量与野外研究中观察到的鱼类反应模式相似。此外，对废水中常见 EDC 的分析定量表明存在雌三醇和雌酮，但这些似乎与观察到的生物反应无关，因为在没有检测到 EDC 的地点，这些物质的含量更高。这些综合观察结果表明，在持续暴露的情况下，ECC 中的鱼类可能具有雌激素活性，并强调了采用基于证据权重（WoE）的方法进行环境监测的优势，因为基于分析的有针对性评估可能支持或不支持识别造成不利生物效应的因果污染物。
