Sediment-associated risks depend on the bioavailable fraction of organic chemicals and cannot be comprehended by their total concentrations. The present study investigated contamination patterns of bioavailable chemicals in sediments from various sites around the globe by using passive equilibrium sampling. The extracts had been characterized previously for mixture effects by in vitro reporter gene assays and were in this study analyzed using gas chromatography-high resolution mass spectrometry for 121 chemicals including both legacy and emerging contaminants. The spatial distribution of the detected chemicals revealed distinct contamination patterns among sampling sites. We identified compounds in common at the different sites but most contaminant mixtures were site-specific. The mixture effects of the detected chemicals were predicted with a mixture toxicity model from effect concentrations of bioactive single chemicals and detected concentrations, applying a joint model for concentration addition and independent action. The predicted mixture effects were dominated by polycyclic aromatic hydrocarbons, and among the chemicals with available effect data, 17% elicited oxidative stress response and 18% activated the arylhydrocarbon receptor. Except for two sites in Sweden, where 11 and 38% of the observed oxidative stress response were explained by the detected chemicals, less than 10% of effects in both biological end points were explained. These results provide a comprehensive investigation of bioavailable contamination patterns of sediments and may serve as an example of employing passive equilibrium sampling as a monitoring technique to integrate the risk of bioavailable sediment-associated chemicals in aquatic environments.

中文翻译：

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被动平衡采样中沉积物的生物可利用的环境污染物模式

与沉积物有关的风险取决于有机化学物质的生物利用度，无法通过其总浓度来理解。本研究通过被动平衡采样研究了来自全球各地的沉积物中生物可利用化学物质的污染模式。提取物先前已通过体外报告基因分析表征了混合物的作用，并在本研究中使用气相色谱-高分辨率质谱法分析了121种化学物质，包括遗留和新出现的污染物。检测到的化学物质的空间分布揭示了采样点之间明显的污染模式。我们确定了在不同位置共有的化合物，但是大多数污染物混合物都是特定于位置的。利用混合物毒性模型，根据生物活性单一化学品的作用浓度和检测到的浓度，使用浓度增加和独立作用的联合模型，预测检测到的化学品的混合效果。预测的混合物作用主要由多环芳烃决定，在具有可用作用数据的化学品中，有17％引起氧化应激反应，有18％活化芳烃受体。除了瑞典的两个地点，其中所检测到的化学物质解释了所观察到的11％和38％的氧化应激反应，而在两个生物学终点中所解释的影响均不到10％。