Recently, the potent antiandrogen 4-methyl-7-diethylaminocoumarin (C47) and its potential transformation products 4-methyl-7-ethylaminocoumarin (C47T1) and 4-methyl-7-aminocoumarin (C47T2) were identified as novel environmental contaminants. We assessed for the first time the sources, distribution, and fate of these compounds in aquatic systems using the Holtemme River (Saxony-Anhalt, Germany), which is a hotspot for these contaminants. To this end, wastewater-treatment plant (WWTP) influent and effluent samples, surface water samples over 3 years, and the longitudinal profiles in water, sediment, and gammarids were analyzed. From the longitudinal profile of the river stretch, the WWTP of Silstedt was identified as the sole point source for these compounds in the River Holtemme, and exposure concentrations in the low micrograms per liter range could be recorded continuously over 3 years. Analysis of WWTP influent and effluent showed a transformation of approximately half of the C47 into C47T1 and C47T2 but no complete removal. A further attenuation of the three coumarins after discharge into the river could be largely attributed to dilution, while transformation was only approximately 20%, thus suggesting a significant persistence in aquatic systems. Experimentally derived partitioning coefficients between water and sediment organic carbon exceeded those predicted using the OPERA quantitative structure–activity relationship tools and polyparameter linear free-energy relationships by up to 93-fold, suggesting cation binding as a significant factor for their sorption behavior. Near-equilibrium conditions between water and sediment were not observed close to the emitting WWTP but farther downstream in the river. Experimental and predicted bioaccumulation factors for gammarids were closely matching, and the concentrations in field-sampled gammarids were close to steady state with exposure concentrations in the water phase of the river. Environ Toxicol Chem 2021;40:3078–3091. © 2021 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

中文翻译：

---

小河流系统中抗雄激素荧光染料 4-Methyl-7-Diethylaminocoumarin 的来源和命运

最近，强效抗雄激素 4-甲基-7-二乙基氨基香豆素 (C47) 及其潜在的转化产物 4-甲基-7-乙基氨基香豆素 (C47T1) 和 4-甲基-7-氨基香豆素 (C47T2) 被确定为新型环境污染物。我们使用 Holtemme 河（德国萨克森-安哈尔特）首次评估了这些化合物在水生系统中的来源、分布和归宿，该河是这些污染物的热点地区。为此，对污水处理厂 (WWTP) 的进水和出水样品、3 年多的地表水样品以及水、沉积物和沙棘的纵向剖面进行了分析。从河段的纵向剖面来看，Silstedt 污水处理厂被确定为 Holtemme 河中这些化合物的唯一点源，低微克/升范围内的暴露浓度可以连续记录超过 3 年。对污水处理厂进水和出水的分析表明，大约一半的 C47 转化为 C47T1 和 C47T2，但没有完全去除。三种香豆素排入河流后的进一步衰减主要归因于稀释，而转化仅为约 20%，因此表明在水生系统中存在显着的持久性。实验得出的水和沉积物有机碳之间的分配系数超过了使用 OPERA 定量构效关系工具和多参数线性自由能关系预测的高达 93 倍，这表明阳离子结合是其吸附行为的重要因素。在排放污水处理厂附近没有观察到水和沉积物之间的近平衡条件，但在河流下游更远的地方没有观察到。γrids 的实验和预测的生物累积因子密切匹配，现场采样的γrids 中的浓度接近于河流水相中暴露浓度的稳态。环境毒物化学2021；40:3078–3091。© 2021 作者。Wiley Periodicals LLC 代表 SETAC 出版的Environmental Toxicology and Chemistry 。