Natural and synthetic steroid hormones and many persistent organic pollutants are of concern for their endocrine-disrupting activities observed in receiving surface waters. Apart from the demonstrated presence of estrogen- and estrogen-mimicking compounds in surface waters, antagonistic (anti-estrogenic) responses originating from wastewater effluent have been reported but are less known. Estrogenicity and anti-estrogenicity were assessed using recombinant yeast estrogen receptor binding assays (YES/YAES) at ten South African wastewater treatment works (WWTWs) and receiving rivers in two separate sampling campaigns during the summer- and winter periods in the area. Four WWTWs were then further investigated to show daily variation in estrogenic endocrine-disrupting activities during the treatment process. Although estrogenicity was notably reduced at most of the WWTWs, some treated effluent and river water samples were shown to be above effect-based trigger values posing an endocrine-disrupting risk for aquatic life and potential health risks for humans. Furthermore, estrogenicity recorded in samples collected upstream from some WWTW discharge points also exceeded some calculated risk trigger values, which highlights the impact of alternative pollution sources contributing towards endocrine disrupting contaminants (EDCs) in the environment. The YAES further showed variable anti-estrogenic activities in treated wastewater. The current study highlights a variety of factors that may affect bioassay outcomes and conclusions drawn from the results for risk decision-making. For example, mismatches were found between estrogenic and anti-estrogenic activity, which suggests a potential masking effect in WWTW effluents and highlights the complexity of environmental samples containing chemical mixtures having variable endocrine-disrupting modes of action. Although the recombinant yeast assay is not without its limitations to show endocrine-disrupting modulation in test water systems, it serves as a cost-effective tier-1 scoping assay for further risk characterisation and intervention.

中文翻译：

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调查南非废水中的（抗）雌激素活动并接受地表水：对可靠监测具有启示意义。

天然和合成的类固醇激素以及许多持久性有机污染物因在接收地表水中观察到的内分泌干扰活性而受到关注。除了已证明在地表水中存在雌激素和类似雌激素的化合物外，还报道了源自废水的拮抗（抗雌激素）反应，但鲜为人知。在该地区的夏季和冬季，通过十个南非废水处理厂（WWTW）并通过两次单独的采样活动接受河流，使用重组酵母雌激素受体结合测定（YES / YAES）评估了雌激素和抗雌激素作用。然后进一步调查了四个WWTW，以显示治疗过程中雌激素内分泌干扰活动的每日变化。尽管在大多数污水处理厂中，雌激素的含量均显着降低，但一些处理过的废水和河水样品显示出高于基于效果的触发值，对水生生物构成了破坏内分泌的风险，并给人类带来了潜在的健康风险。此外，从某些WWTW排放点上游采集的样品中记录的雌激素性也超过了一些计算得出的风险触发值，这突显了替代污染源对环境中内分泌干扰物（EDC）的贡献。YAES还显示出在处理过的废水中可变的抗雌激素活性。本研究强调了可能影响生物测定结果的各种因素，以及从风险决策中得出的结论。例如，在雌激素和抗雌激素活性之间发现错配，这表明对WWTW废水具有潜在的掩盖作用，并突出了含有具有可变内分泌干扰作用模式的化学混合物的环境样品的复杂性。尽管重组酵母测定法并非没有局限性，不能在测试水系统中显示破坏内分泌的调节作用，但它可作为一种经济有效的1级作用域测定法，用于进一步的风险表征和干预。