Environmental Biogeochemistry and Ecotoxicology, Department F.-A. Forel for Environmental and Aquatic Sciences, School of Earth and Environmental Sciences, Faculty of Science, and Institute for Environmental Sciences, University of Geneva, Uni Carl Vogt, 66, Boulevard Carl-Vogt, CH-1211 Genève 4, Switzerland.
Environmental Biogeochemistry and Ecotoxicology, Department F.-A. Forel for Environmental and Aquatic Sciences, School of Earth and Environmental Sciences, Faculty of Science, and Institute for Environmental Sciences, University of Geneva, Uni Carl Vogt, 66, Boulevard Carl-Vogt, CH-1211 Genève 4, Switzerland.
Aquat Toxicol. 2020 Jul;224:105502. doi: 10.1016/j.aquatox.2020.105502. Epub 2020 May 18.
The present study examined the effect of titanium dioxide nanoparticles (nanoTiO) and mercury (Hg) compounds on the green alga, Chlamydomonas reinhardtii. Mixtures containing nanoTiO of different primary sizes (5 nm, 15 nm and 20 nm), inorganic Hg (IHg) or monomethyl Hg (CHHg, MeHg) were studied and compared with individual treatments. Oxidative stress and membrane damage were examined. Stability of nanoTiO materials in terms of hydrodynamic size and surface charge as well as Hg adsorption on different nanoTiO materials were characterized. The uptake of Hg compounds in the absence and presence of nanoTiO was also quantified. Results show that increasing concentrations of nanoTiO with different primary size diminished oxidative stress and membrane damage induced by high concentrations of IHg or MeHg, due to the adsorption of Hg on the nanoTiO aggregates and consequent decrease of cellular Hg concentrations. The observed alleviation effect of nanoTiO materials on Hg biouptake and toxicity was more pronounced for the materials with smaller primary size. IHg adsorbed onto the nanoTiO materials to a higher extent than MeHg. The present study highlights that the effects of contaminants are modulated by the co-existing engineered nanomaterials; therefore, it is essential to get a better understanding of their combined effect in the environment.
本研究考察了二氧化钛纳米粒子（nanoTiO）和汞（Hg）化合物对绿藻莱茵衣藻的影响。研究了含有不同原始粒径（5nm、15nm 和 20nm）的纳米 TiO、无机 Hg（IHg）或单甲基 Hg（CHHg，MeHg）的混合物，并与单独处理进行了比较。考察了氧化应激和膜损伤。表征了纳米 TiO 材料在水动力粒径和表面电荷方面的稳定性，以及不同纳米 TiO 材料对 Hg 的吸附。还定量了 Hg 化合物在不存在和存在纳米 TiO 时的摄取情况。结果表明，不同原始粒径的纳米 TiO 浓度增加，减轻了高浓度 IHg 或 MeHg 引起的氧化应激和膜损伤，这是由于 Hg 在纳米 TiO 聚集体上的吸附以及细胞内 Hg 浓度的相应降低所致。对于原始粒径较小的纳米 TiO 材料，观察到纳米 TiO 材料对 Hg 生物摄取和毒性的缓解作用更为明显。与 MeHg 相比，IHg 更易吸附到纳米 TiO 材料上。本研究强调了共存的工程纳米材料会调节污染物的影响；因此，必须更好地了解它们在环境中的联合效应。
