title: Elevated CO2levels increase the toxicity of ZnO nanoparticles to goldfish (Carassius auratus) in a water-sediment ecosystem.
abstract: Concerns about the environmental safety of metal-based nanoparticles (MNPs) in aquatic ecosystems are increasing. Simultaneously, elevated atmospheric CO2levels are a serious problem worldwide, making it possible for the combined exposure of MNPs and elevated CO2to the ecosystem. Here we studied the toxicity of nZnO to goldfish in a water-sediment ecosystem using open-top chambers flushed with ambient (400±10μL/L) or elevated (600±10μL/L) CO2for 30days. We measured the content of Zn in suspension and fish, and analyzed physiological and biochemical changes in fish tissues. Results showed that elevated CO2increased the Zn content in suspension by reducing the pH value of water and consequently enhanced the bioavailability and toxicity of nZnO. Elevated CO2led to higher accumulation of Zn in fish tissues (increased by 43.3%, 86.4% and 22.5% in liver, brain and muscle, respectively) when compared to ambient. Elevated CO2also intensified the oxidative damage to fish induced by nZnO, resulting in higher ROS intensity, greater contents of MDA and MT and lower GSH content in liver and brain. Our results suggest that more studies in natural ecosystems are needed to better understand the fate and toxicity of nanoparticles in future CO2levels.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210046, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Yin
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210046, China.
authors.forename: Zhengxue
authors.initials: Z
authors.lastname: Hu
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210046, China. Electronic address: du@nju.edu.cn.
authors.forename: Wenchao
authors.initials: W
authors.lastname: Du
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210046, China.
authors.forename: Fuxun
authors.initials: F
authors.lastname: Ai
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210046, China.
authors.forename: Rong
authors.initials: R
authors.lastname: Ji
authors.affiliation: Department of Chemistry, The University of Texas at El Paso, El Paso, TX 79968, United States; Environmental Science and Engineering PhD program, The University of Texas at El Paso, El Paso, TX 79968, United States; University of California Center for Environmental Implications of Nanotechnology (UC CEIN), The University of Texas at El Paso, El Paso, TX 79968, United States.
authors.forename: Jorge L
authors.initials: JL
authors.lastname: Gardea-Torresdey
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210046, China. Electronic address: hyguo@nju.edu.cn.
authors.forename: Hongyan
authors.initials: H
authors.lastname: Guo
mesh_terms: D000818:Animals; D002245:Carbon Dioxide / Q000494:pharmacology*; D017753:Ecosystem; D019015:Geologic Sediments; D005978:Glutathione / Q000378:metabolism; D006054:Goldfish; D006863:Hydrogen-Ion Concentration; D008315:Malondialdehyde / Q000032:analysis; D053768:Metal Nanoparticles / Q000633:toxicity; D008668:Metallothionein / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000032:analysis / Q000378:metabolism; D014018:Tissue Distribution; D015034:Zinc Oxide / Q000493:pharmacokinetics / Q000633:toxicity*
chemical_list: D017382:Reactive Oxygen Species; D002245:Carbon Dioxide; D008315:Malondialdehyde; D008668:Metallothionein; D005978:Glutathione; D015034:Zinc Oxide
keywords: CO(2); Fish; Toxicology; Water-sediment; ZnO nanoparticles