Abstract：
The scientific advancement of water quality criteria (WQC) stands as one of the paramount challenges in ensuring the security of aquatic ecosystem. The region-dependent species distribution and water quality characteristics would impact the toxicity of pollutant, which would further affect the derivation of WQC across regions. Presently, however, numerous countries adhere to singular WQC values. The \"One-size-fits-all\" WQC value for a given pollutant may lead to either \"over-protection\" or \"under-protection\" of organisms in specific region. In this study, we used cadmium(Cd) pollution in surface waters of China as a case study to shed light on this issue. This study evaluated critical water quality parameters and species distribution characteristics to modify WQC for Cd across distinct regions, thus unveiling the geographical variations in ecological risk for Cd throughout China. Notably, regional disparities in ecological risk emerged a substantial correlation with water hardness, while species-related distinctions magnified these regional variations. After considering the aforementioned factors, the variation in long-term WQC among different areas reached 84-fold, while the divergence in risk quotient extended to 280-fold. This study delineated zones of both heightened and diminished ecological susceptibility of Cd, thereby establishing a foundation for regionally differentiated management strategies.
摘要：
水质标准（WQC）的科学进步是确保水生生态系统安全的首要挑战之一。区域依赖的物种分布和水质特征会影响污染物的毒性，这将进一步影响WQC跨地区的推导。目前,然而,许多国家坚持单一的WQC值。给定污染物的“一刀切”WQC值可能导致特定区域内生物的“过度保护”或“保护不足”。在这项研究中,我们使用中国地表水中的镉（Cd）污染作为案例研究来阐明这一问题。这项研究评估了关键的水质参数和物种分布特征，以修改不同地区Cd的WQC。从而揭示了整个中国Cd生态风险的地理差异。值得注意的是,生态风险的区域差异与水硬度有很大的相关性，而与物种相关的区别放大了这些区域差异。在考虑了上述因素后，不同地区之间的长期WQC差异达到84倍，而风险商的差异扩大到280倍。这项研究描绘了Cd的生态敏感性升高和降低的区域，从而为区域差异化管理策略奠定基础。
