University of Calgary, Department of Biological Sciences, 2500 University Drive N.W., Calgary, T2N 1N4, Alberta, Canada.
University of Calgary, Department of Biological Sciences, 2500 University Drive N.W., Calgary, T2N 1N4, Alberta, Canada.
Environ Pollut. 2020 Apr;259:113757. doi: 10.1016/j.envpol.2019.113757. Epub 2019 Dec 13.
While wastewater treatment standards have been progressively increasing, emerging contaminants such as pharmaceuticals can nonetheless pass through treatment and end up in our watersheds. Pharmaceuticals in the parts-per-billion range can impact fish behavior, survival, and recruitment in the wild. However, the ecological risk posed by whole municipal wastewater effluents (MWWE), a complex mixture, is not clear. This knowledge gap is particularly evident for early lifestages (ELS) of fish, and because effluent discharge events are typically short, the effects of short-term MWWE exposures to ELS fish are particularly important from an environmental perspective. Here we tested the effects of rapid 30-min exposures, and short-term 24- and 72-h exposures to MWWE on development, behaviors, and stress response in zebrafish (Danio rerio) embryos, larvae, and juveniles. We obtained 24-h composite samples of tertiary-treated MWWE that contained a mixture of chemicals with affinities for serotonergic, adrenergic, dopaminergic, and ion-channel receptors. Embryos exposed to 5%, 10%, and 50% MWWE experienced developmental delays in somitogenesis and hatching rate, although there was no effect on survival. Embryonic photomotor responses were affected following 30-min and 24-h exposures to 10% and 50% MWWE, and larval visual motor responses were reduced from 24-h exposure to 10% MWWE. Exposure to 10% MWWE dulled the juvenile cortisol and lactate response following an acute air-exposure. Compromised behavioral and stress performances demonstrate the capacity of MWWE to impact phenotypes critical to the survival of fish in the environment. Taken together, we found that zebrafish were sensitive to toxic effects of MWWE at multiple life-stages.
虽然废水处理标准在逐步提高，但仍有一些新兴污染物（如药物）可以通过处理而进入我们的流域。痕量的药物会影响鱼类在野外的行为、生存和繁殖。然而，整个城市废水（MWWE）这一复杂混合物所构成的生态风险尚不清楚。对于鱼类的早期生活阶段（ELS），这种知识差距尤其明显，并且由于废水排放事件通常持续时间较短，因此从环境角度来看，ELS 鱼类短期接触 MWWE 的影响尤为重要。在这里，我们测试了快速 30 分钟暴露、短期 24 小时和 72 小时暴露对斑马鱼（Danio rerio）胚胎、幼鱼和幼鱼发育、行为和应激反应的影响。我们获得了经过三级处理的 MWWE 的 24 小时复合样本，其中含有对 5-羟色胺能、肾上腺素能、多巴胺能和离子通道受体具有亲和力的化学物质混合物。暴露于 5%、10%和 50%MWWE 的胚胎在体节形成和孵化率方面出现发育延迟，尽管对存活率没有影响。胚胎的光运动反应在 30 分钟和 24 小时暴露于 10%和 50%MWWE 后受到影响，而幼鱼的视觉运动反应在 24 小时暴露于 10%MWWE 后降低。暴露于 10%MWWE 会削弱幼鱼在急性空气暴露后的皮质醇和乳酸反应。受损的行为和应激表现表明，MWWE 有能力影响鱼类在环境中生存的关键表型。总的来说，我们发现斑马鱼对 MWWE 的多种生命阶段的毒性作用敏感。
