Zinc oxide–engineered nanoparticles: Dissolution and toxicity to marine phytoplankton

Authors

  • Ai-Jun Miao,

    Corresponding author
    1. State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, Jiangsu Province 210093, China
    2. Department of Marine Science, Texas A&M University at Galveston, Galveston, Texas 77553, USA
    3. Department of Marine Biology, Texas A&M University at Galveston, Galveston, Texas 77553, USA
    • State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, Jiangsu Province 210093, China
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  • Xue-Yin Zhang,

    1. State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, Jiangsu Province 210093, China
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  • Zhiping Luo,

    1. Microscopy and Imaging Center, Texas A&M University, College Station, Texas 77843, USA
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  • Chi-Shuo Chen,

    1. School of Engineering, University of California—Merced, Merced, California 95344, USA
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  • Wei-Chun Chin,

    1. School of Engineering, University of California—Merced, Merced, California 95344, USA
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  • Peter H. Santschi,

    1. Department of Marine Science, Texas A&M University at Galveston, Galveston, Texas 77553, USA
    2. Department of Oceanography, Texas A&M University, College Station, Texas 77843, USA
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  • Antonietta Quigg

    1. Department of Marine Science, Texas A&M University at Galveston, Galveston, Texas 77553, USA
    2. Department of Marine Biology, Texas A&M University at Galveston, Galveston, Texas 77553, USA
    3. Department of Oceanography, Texas A&M University, College Station, Texas 77843, USA
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Abstract

It is now widely recognized that dissolution plays an important role in metallic nanoparticle toxicity, but to what extent remains unclear. In the present study, it was found that ZnO-engineered nanoparticle (ZnO-EN) toxicity to the marine diatom Thalassiosira pseudonana could be solely explained by zinc ion (Zn2+) release. This is based on comparable inhibitive effects from ZnO-EN addition media, with or without the ultrafiltration through a 3-kD membrane, and from the media in which only Zn2+ was added. Considering the importance of dissolution in ZnO-EN toxicity, Zn2+ release kinetics was systematically examined under different conditions for the first time. It was found to be mainly influenced by pH as well as the specific surface area of the nanoparticles. In contrast, natural organic compounds either enhance or reduce Zn2+ release, depending on their chemical composition and concentration. Compared with deionized water, ZnO-EN dissolution rates were accelerated in seawater, whereas ZnO-EN concentration itself only had a very small effect on Zn2+ release. Therefore, dissolution as affected by several physicochemical factors should not be neglected in the effects, behavior, and fate of ENs in the environment. Environ. Toxicol. Chem. 2010;29:2814–2822. © 2010 SETAC

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