Zhai Yujia, Hunting Ellard R, Wouterse Marja, Peijnenburg Willie J G M, Vijver Martina G
Institute of Environmental Sciences (CML), Leiden University, P.O. Box 9518, 2300 RA, Leiden, The Netherlands.
Institute of Environmental Sciences (CML), Leiden University, P.O. Box 9518, 2300 RA, Leiden, The Netherlands.
Ecotoxicol Environ Saf. 2017 Nov;145:349-358. doi: 10.1016/j.ecoenv.2017.07.031. Epub 2017 Jul 28.
Metal-based engineered nanomaterials (ENMs) are known to affect bacterial processes and metabolic activities. While testing their negative effects on biological components, studies traditionally rely on initial exposure concentrations and thereby do not take into consideration the dynamic behavior of ENMs that ultimately determines exposure and toxicity (e.g. ion release). Moreover, functional responses of soil microbial communities to ENMs exposure can be caused by both the particulate forms and the ionic forms, yet their relative contributions remain poorly understood. Therefore, we investigated the dynamic changes of exposure concentrations of three different types of ENMs (nano-ZnO, -Cu and -Pb) and submicron particles (SMPs) in relation to their impact on the capacity of soil bacterial communities to utilize carbon substrates. The different ENMs were chosen to differ in dissolution potential. The dynamic exposures of ENMs were considered using a time weighted average (TWA) approach. The joint toxicity of the particulate forms and the ionic forms of ENMs was evaluated using a response addition model. Our results showed that the effect concentrations of spherical nano-ZnO, -Cu and SMPs, and Pb-based perovskites expressed as TWA were lower than expressed as initial concentrations. Both particulate forms and ionic forms of spherical 18nm, 43nm nano-ZnO and 50nm, 100nm nano-Cu contribute to the overall response at the EC levels. The particulate forms for 150nm, 200nm and 900nm ZnO SMPs and rod-shaped 78nm nano-Cu mainly affected the soil microbial metabolic potential, while the Cu ions released from spherical 25nm nano-Cu, 500nm Cu SMPs and Pb ions released from perovskites mainly described the effects to bacterial communities. Our results indicate that the dynamic exposure of ENMs and relative contributions of particles and ions require consideration in order to pursue a naturally realistic assessment of environmental risks of metal-based ENMs.
已知金属基工程纳米材料（ENMs）会影响细菌过程和代谢活动。在测试它们对生物成分的负面影响时，传统研究依赖于初始暴露浓度，因此没有考虑到最终决定暴露和毒性的ENMs的动态行为（例如离子释放）。此外，土壤微生物群落对ENMs暴露的功能反应可能由颗粒形式和离子形式共同引起，但其相对贡献仍知之甚少。因此，我们研究了三种不同类型的ENMs（纳米氧化锌、纳米铜和纳米铅）以及亚微米颗粒（SMPs）的暴露浓度动态变化，及其对土壤细菌群落利用碳底物能力的影响。选择不同的ENMs使其在溶解潜力上有所差异。使用时间加权平均（TWA）方法来考虑ENMs的动态暴露。使用响应加和模型评估ENMs颗粒形式和离子形式的联合毒性。我们的结果表明，以TWA表示的球形纳米氧化锌、纳米铜和SMPs以及铅基钙钛矿的效应浓度低于以初始浓度表示的效应浓度。球形18nm、43nm纳米氧化锌和50nm、100nm纳米铜的颗粒形式和离子形式在EC水平上都对整体反应有贡献。150nm、200nm和900nm氧化锌SMPs以及棒状78nm纳米铜的颗粒形式主要影响土壤微生物代谢潜力，而球形25nm纳米铜、500nm铜SMPs释放的铜离子以及钙钛矿释放的铅离子主要描述了对细菌群落的影响。我们的结果表明，为了对金属基ENMs的环境风险进行自然现实的评估，需要考虑ENMs的动态暴露以及颗粒和离子的相对贡献。
