Department of Civil, Architectural and Environmental Engineering, Missouri University of Science and Technology, Rolla, MO, 65409, United States.
Department of Civil, Architectural and Environmental Engineering, Missouri University of Science and Technology, Rolla, MO, 65409, United States; The Center for Research in Energy and Environment (CREE), Missouri University of Science and Technology, Rolla, MO, 65409, United States.
Chemosphere. 2021 Jan;263:127958. doi: 10.1016/j.chemosphere.2020.127958. Epub 2020 Aug 15.
Nanoparticles (NPs) can significantly influence toxicity imposed by toxic metals. However, this impact has not been quantified. In this research, we investigated the effect of nano-TiO on lead (Pb) accumulation and the resultant toxicity using water flea Ceriodaphnia dubia (C. dubia) as the testing organism. We used a two-compartment modeling approach, which included a two-compartment accumulation model and a toxicodynamic model, on the basis of Pb body tissue accumulation, to quantify the impact of nano-TiO on Pb toxicity. The effect of algae on the combined toxicity of Pb and nano-TiO was also quantified. The two-compartment accumulation model could well quantify Pb accumulation kinetics in two-compartments of C. dubia, the gut and the rest of the body tissue in the presence of nano-TiO. Modeling results suggested that the gut quickly accumulates Pb through active uptake from the mouth, but the rest of the body tissue slowly accumulates Pb from the gut. The predicted Pb distribution within C. dubia was verified by depuration modeling results from an independent depuration test. The survivorship of C. dubia as a function of Pb accumulated in the body tissue and exposure time can be well described using a toxicodynamic model. The effects of algae on Pb accumulation in different compartments of C. dubia and the toxicity in the presence of nano-TiO were also well described using the two-compartment modeling approach. Therefore, the novel two-compartment modeling approach provides a useful tool for assessing the effect of NPs on aquatic ecosystems where toxic metals are present.
纳米颗粒（NPs）可以显著影响有毒金属所造成的毒性。然而，这种影响尚未量化。在这项研究中，我们使用水蚤（C. dubia）作为测试生物，研究了纳米 TiO2 对铅（Pb）积累的影响，以及由此产生的毒性。我们使用了一种两 compartment 建模方法，该方法包括两 compartment 积累模型和毒代动力学模型，基于 Pb 组织积累，对纳米 TiO2 对 Pb 毒性的影响进行了量化。我们还量化了藻类对 Pb 和纳米 TiO2 联合毒性的影响。两 compartment 积累模型可以很好地量化纳米 TiO2 存在时，C. dubia 体内两 compartment（肠道和其余组织）中 Pb 积累的动力学。建模结果表明，肠道通过从口中主动摄取快速积累 Pb，但其余组织则从肠道缓慢积累 Pb。用独立净化试验的净化模型结果验证了 C. dubia 体内 Pb 的预测分布。用毒代动力学模型可以很好地描述 C. dubia 的存活率随体内组织中 Pb 积累和暴露时间的变化关系。两 compartment 建模方法还很好地描述了藻类对 C. dubia 不同 compartment 中 Pb 积累和纳米 TiO2 存在时毒性的影响。因此，这种新的两 compartment 建模方法为评估 NPs 对存在有毒金属的水生生态系统的影响提供了有用的工具。
