title: Surfactants present complex joint effects on the toxicities of metal oxide nanoparticles.
abstract: The potential toxicities of nanoparticles (NPs) have been intensively discussed over the past decade. In addition to their single toxicities, NPs can interact with other environmental chemicals and thereby exert joint effects on biological systems and the environment. The present study investigated the combined toxicities of NPs and surfactants, which are among the chemicals that most likely coexist with NPs. Photobacterium phosphoreum was employed as the model organism. The results indicate that surfactants with different ion types can alter the properties of NPs (i.e., particle size and surface charge) in different ways and present complex joint effects on NP toxicities. Mixtures of different NPs and surfactants exhibited antagonistic, synergistic, and additive effects. In particular, the toxicity of ZnO was observed to result from its dissolved Zn(2+); thus, the joint effects of the ZnO NPs and surfactants can be explained by the interactions between the Zn ions and the surfactants. Our study suggests that the potential hazards caused by mixtures of NPs and surfactants are different from those caused by single NPs. Because surfactants are extensively used in the field of nanotechnology and are likely to coexist with NPs in natural waters, the ecological risk assessments of NPs should consider the impacts of surfactants.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
authors.forename: Dali
authors.initials: D
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Collaborative Innovation Center for Regional Environmental Quality, China. Electronic address: lzhifen@tongji.edu.cn.
authors.forename: Zhifen
authors.initials: Z
authors.lastname: Lin
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
authors.forename: Zhifeng
authors.initials: Z
authors.lastname: Yao
authors.affiliation: School of the Environment, State Key Laboratory of Pollution Control and Resources Reuse, Nanjing University, Nanjing 210093, China.
authors.forename: Hongxia
authors.initials: H
authors.lastname: Yu
mesh_terms: D002413:Cations, Divalent / Q000737:chemistry / Q000633:toxicity; D004785:Environmental Pollutants / Q000737:chemistry / Q000633:toxicity*; D053758:Nanoparticles / Q000737:chemistry / Q000633:toxicity*; D010776:Photobacterium / Q000166:cytology / Q000187:drug effects*; D013501:Surface-Active Agents / Q000737:chemistry / Q000633:toxicity*; D015034:Zinc Oxide / Q000737:chemistry / Q000633:toxicity*
chemical_list: D002413:Cations, Divalent; D004785:Environmental Pollutants; D013501:Surface-Active Agents; D015034:Zinc Oxide
keywords: Combined toxicity; Joint effect; Nanoparticle; Surfactant