Lewis Phoebe, Neale Peta A, Tan Hung, Leeder John, O'Malley Elissa, Taylor Mark P, Leusch Frederic D L, Saaristo Minna
Environment Protection Authority (EPA) Victoria, EPA Science, Macleod, Victoria, 3085, Australia.
Australian Rivers Institute, School of Environment and Science, Griffith University, Southport, Queensland, 4222, Australia.
Environ Pollut. 2025 Jul 8;383:126807. doi: 10.1016/j.envpol.2025.126807.
Targeted chemical analysis is widely used for water quality monitoring but has significant limitations as it cannot detect unknown chemicals or account for mixture effects. To address these gaps, effect-based methods (EBM) are gaining interest. Here, we applied a battery of in vitro bioassays to wastewater influent and effluent from four wastewater treatment plants (WWTPs) in Victoria, Australia, as well as surface water upstream and downstream of the WWTPs, to assess the potential risks from mixture effects. The bioassays were complemented with targeted chemical analysis of over 600 chemicals. Chemical analysis and bioanalysis showed higher chemical concentrations and effects in discharged effluent compared to surface waters, confirming WWTPs as key pollution sources. Though most WWTPs were able to remove over 80 % of bacterial toxicity, photosystem II inhibition, estrogenic activity and oxidative stress response, one site had poor removal of estrogenic and aryl hydrocarbon receptor (AhR) activity. This site also had a lower median chemical removal efficiency (40 %) compared to the other WWTPs (72-88 %). Surface water samples downstream of some of the WWTPs exceeded ecological effect-based trigger values (ecoEBTs), suggesting that effluent discharge contributes to increased estrogenic and AhR activity, as well as oxidative stress. Despite the large number of detected chemicals, only a small fraction of the observed biological effects could be explained using iceberg modelling, highlighting the presence of unknown bioactive contaminants. These findings underscore the need for integrating chemical analysis with EBM to more comprehensively assess water quality, and improve protection of aquatic ecosystems, worldwide.
靶向化学分析广泛应用于水质监测，但存在显著局限性，因为它无法检测未知化学物质或考虑混合物效应。为了弥补这些差距，基于效应的方法（EBM）越来越受到关注。在此，我们对澳大利亚维多利亚州四个污水处理厂（WWTPs）的进水和出水以及污水处理厂上下游的地表水进行了一系列体外生物测定，以评估混合物效应带来的潜在风险。生物测定辅以对600多种化学物质的靶向化学分析。化学分析和生物分析表明，与地表水相比，排放出的污水中化学物质浓度更高、效应更强，证实污水处理厂是主要污染源。尽管大多数污水处理厂能够去除超过80%的细菌毒性、光系统II抑制、雌激素活性和氧化应激反应，但有一个污水处理厂对雌激素和芳烃受体（AhR）活性的去除效果较差。与其他污水处理厂（72 - 88%）相比，该污水处理厂的化学物质去除效率中位数也较低（40%）。一些污水处理厂下游的地表水样本超过了基于生态效应的触发值（ecoEBTs），这表明污水排放导致雌激素和AhR活性以及氧化应激增加。尽管检测到大量化学物质，但使用冰山模型只能解释一小部分观察到的生物效应，这突出了未知生物活性污染物的存在。这些发现强调了将化学分析与基于效应的方法相结合的必要性，以便更全面地评估水质，并在全球范围内加强对水生生态系统的保护。
