Around the globe, on-site wastewater-treatment systems (OWTSs) are critical for rural communities without access to a municipal sewer system. However, their treatment efficiency does not match that of modern wastewater-treatment plants. The impact of OWTS discharge on nearby aquatic ecosystems and their resident fish species is poorly understood. In the present study, larval and adult fathead minnows (Pimephales promelas) and adult sunfish (Lepomis macrochirus) were exposed for 21 days to two trace organic contaminant (TOrC) mixtures replicating water chemistry derived from a previous environmental study. Larval fathead minnows were assessed for survival, growth, predator avoidance, and feeding efficiency. Adult fathead minnows and sunfish were assessed for a suite of physiological endpoints (condition indices, vitellogenin, glucose), histological changes, and fecundity. The only observed effect of TOrC mixture exposure on larval fathead minnows was a decrease in feeding efficiency. Effects were mixed in exposed adult fishes, except for male sunfish which realized a significant induction of vitellogenin (p < 0.05). The consequences of TOrC mixture exposure in the present controlled laboratory study match effects observed in wild-caught sunfish in a corresponding field study. The present study begins to bridge the gap by connecting nonpoint OWTS pollution with biological effects observed in resident lake fish species. Given the effects observed despite the brevity of the laboratory mixture exposure, longer-term studies are warranted to understand the full impacts of OWTS discharge to nearby aquatic ecosystems. Environ Toxicol Chem 2021;40:3193–3204. © 2021 SETAC. This article has been contributed to by US Government employees and their work is in the public domain in the USA.

中文翻译：

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将现场废水处理排放中的微量有机污染物与生物效应联系起来

在全球范围内，现场废水处理系统 (OWTS) 对于无法使用市政下水道系统的农村社区至关重要。然而，它们的处理效率与现代污水处理厂不匹配。OWTS 排放对附近水生生态系统及其常驻鱼类的影响知之甚少。在本研究中，幼体和成体黑头鲦鱼 ( Pimephales promelas ) 和成体翻车鱼 ( Lepomis macrochirus) 暴露于两种微量有机污染物 (TOrC) 混合物中 21 天，这些混合物复制了源自先前环境研究的水化学。对幼虫黑头鲦鱼的生存、生长、捕食者回避和摄食效率进行了评估。对成年黑头鲦鱼和翻车鱼的一系列生理终点（条件指数、卵黄蛋白、葡萄糖）、组织学变化和繁殖力进行了评估。TOrC 混合物暴露对幼体黑头鲦鱼的唯一观察到的影响是摄食效率降低。在暴露的成年鱼中效果是混合的，除了雄性太阳鱼实现了显着的卵黄蛋白诱导（p < 0.05)。在本受控实验室研究中，TOrC 混合物暴露的后果与在相应的实地研究中在野生捕获的翻车鱼中观察到的效果相匹配。本研究开始通过将非点 OWTS 污染与在常驻湖泊鱼类中观察到的生物效应联系起来来弥合差距。尽管实验室混合物暴露时间很短，但鉴于观察到的影响，有必要进行长期研究以了解 OWTS 排放对附近水生生态系统的全面影响。环境毒物化学2021；40:3193–3204。© 2021 SETAC。本文由美国政府雇员贡献，他们的工作在美国属于公共领域。