Risk assessment of chemicals is still primarily focusing on single compound evaluation, even if environmental contamination consists of a mixture of pollutants. The concentration addition (CA) and independent action (IA) models have been developed to predict mixture toxicity. Both models assume no interaction between the components, resulting in an additive mixture effect. In the present study, the embryo toxicity test (OECD TG no. 236) with zebrafish embryos (Danio rerio) was performed to investigate whether the toxicity caused by binary, ternary, and quaternary mixtures of organic (Benzo[a]pyrene, perfluorooctanesulfonate, and 3,3´,4,4´,5-pentachlorobiphenyl 126) and inorganic (arsenate) pollutants can be predicted by CA and IA. The acute toxicity and sub-lethal alterations such as lack of blood circulation were investigated. The models estimated the mixture toxicity well and most of the mixtures were additive. However, the binary mixture of PFOS and PCB126 caused a synergistic effect, with almost a ten-fold difference between the observed and predicted LC₅₀-value. For most of the mixtures, the CA model was better in predicting the mixture toxicity than the IA model, which was not expected due to the chemicals’ different modes of action. In addition, some of the mixtures caused sub-lethal effects not observed in the single compound toxicity tests. The mixture of PFOS and BaP caused a division of the yolk and imbalance was caused by the combination of PFOS and As and the ternary mixture of PFOS, As, and BaP. Interestingly, PFOS was part of all three mixtures causing the mixture specific sub-lethal effects. In conclusion, the present study shows that CA and IA are mostly resulting in good estimations of the risks that mixtures with few components are posing. However, for a more reliable assessment and a better understanding of mixture toxicity, further investigations are required to study the underlying mechanisms.

即使环境污染由多种污染物组成，化学品的风险评估仍主要侧重于单一化合物的评估。已经开发了浓度添加 (CA) 和独立作用 (IA) 模型来预测混合物毒性。两种模型都假设成分之间没有相互作用，从而产生加性混合效应。在本研究中，斑马鱼胚胎 ( Danio rerio ) 的胚胎毒性试验 (OECD TG no. 236)) 用于调查是否由有机（苯并[a]芘、全氟辛烷磺酸盐和 3,3',4,4',5-五氯联苯 126）和无机（砷酸盐）污染物的二元、三元和四元混合物引起的毒性可以通过 CA 和 IA 来预测。研究了急性毒性和亚致死改变，例如缺乏血液循环。这些模型很好地估计了混合物的毒性，并且大多数混合物是添加剂。_{然而，全氟辛烷磺酸和 PCB126 的二元混合物产生了协同效应，观察到的和预测的 LC 50}之间几乎相差十倍-价值。对于大多数混合物，CA 模型在预测混合物毒性方面比 IA 模型更好，由于化学品的不同作用模式，这不是预期的。此外，一些混合物引起了在单一化合物毒性试验中未观察到的亚致死效应。PFOS 和 BaP 的混合导致蛋黄分裂，而不平衡是由 PFOS 和 As 的组合以及 PFOS、As 和 BaP 的三元混合物引起的。有趣的是，全氟辛烷磺酸是所有三种混合物的一部分，导致混合物具有特定的亚致死效应。总之，本研究表明，CA 和 IA 主要是对含有少量成分的混合物所带来的风险做出了良好的估计。然而，为了更可靠的评估和更好地了解混合物的毒性，