The European City Fish project aimed to develop a generic methodology for ecological risk assessment for urban rivers. Since traditional methods only consider a small fraction of substances present in the water cycle, biological effect monitoring is required for a more reliable assessment of the pollution status. A major challenge for environmental risk assessment (ERA) is the application of adverse outcome pathways (AOP), i.e. the linking of pollutant exposure via early molecular and biochemical changes to physiological effects and, ultimately, effects on populations and ecosystems.

We investigated the linkage between responses at these different levels. Many AOP aspects were investigated, from external and internal exposure to different classes of micropollutants, via molecular key events (MKE) the impacts on organs and organisms (fish physiology), to changes in the population dynamics of fish. Risk assessment procedures were evaluated by comparing environmental quality standards, bioassay responses, biomarkers in caged and feral fish, and the impact on fish populations. Although no complete AOP was observed, indirect relationships linking pollutant exposure via MKE to impaired locomotion were demonstrated at the most polluted site near a landfill for chemical waste. The pathway indicated that several upstream key events requiring energy for stress responses and toxic defence are likely to converge at a single common MKE: increased metabolic demands. Both fish biomarkers and the bioanalytical SIMONI strategy are valuable indicators for micropollutant risks to fish communities.

欧洲城市鱼类项目旨在开发一种通用方法来评估城市河流的生态风险。由于传统方法仅考虑水循环中存在的一小部分物质，因此需要生物效应监测以更可靠地评估污染状况。环境风险评估（ERA）的主要挑战是不良后果途径（AOP）的应用，即污染物的暴露通过早期的分子和生化变化与生理影响以及最终对种群和生态系统的影响联系起来。

我们调查了这些不同级别的响应之间的联系。研究了许多AOP方面，从外部和内部暴露于不同种类的微污染物，通过分子关键事件（MKE）对器官和生物的影响（鱼类生理学），到鱼类种群动态的变化。通过比较环境质量标准，生物测定反应，网箱和野性鱼类中的生物标志物以及对鱼类种群的影响，对风险评估程序进行了评估。尽管未观察到完整的AOP，但在化学废物填埋场附近污染最严重的地点，证明了通过MKE暴露污染物与运动受损之间的间接关系。该途径表明，几个上游关键事件需要能量来应对压力和毒性防御作用，可能会集中在一个共同的MKE上：新陈代谢需求增加。鱼类生物标志物和SIMONI生物分析策略都是鱼类群落中微污染物风险的重要指标。