First Institute of Oceanography, State Oceanic Administration, Qingdao 266061, China.
Ecotoxicol Environ Saf. 2013 May;91:52-60. doi: 10.1016/j.ecoenv.2013.01.007. Epub 2013 Jan 31.
In this study, bioaccumulation and sub-acute toxicity of water-borne nano-ZnO in the test fish, juvenvile carp (Cyprinus Carpio) were evaluated. To clarify the contribution of particle size and free Zn ion to NPs toxicity, its bulk counterparts (bulk-ZnO) and the released Zn(2+) were also tested. The results showed that after a 30-day exposure, 50mg/L of nano-ZnO and bulk-ZnO could be significantly accumulated and distributed in various tissues of fish, but nano-ZnO exhibited more hyper-bioaccumulation than bulk-ZnO. Liver and gill might be the target tissues with exposure to nano-ZnO, instead, the target tissue for bulk-ZnO might be intestine. Also, 50mg/L of nano-ZnO caused more severe histopathological changes than the same concentration of bulk-ZnO, which was in accordance with the induction of higher levels of intracellular oxidative stress. The effects of dissolved Zn ions were assessed and the ion toxicity was negligible herein. The results of this study indicated that the observed toxicities of nano-ZnO were not likely a result solely of particle dissolution and identified as a function of particle toxicity and the possibility for a size dependence. The main toxic mechanism of nano-ZnO was possibly by increasing cellular oxidative stress response.
本研究评价了水中纳米 ZnO 在试验鱼类（鲤鱼）中的生物积累和亚急性毒性。为了阐明颗粒大小和游离 Zn 离子对纳米粒子毒性的贡献，还测试了其本体对照物（块状 ZnO）和释放的 Zn(2+)。结果表明，在 30 天暴露后，50mg/L 的纳米 ZnO 和块状 ZnO 均可显著地在鱼类的各种组织中积累和分布，但纳米 ZnO 的超积累能力强于块状 ZnO。肝脏和鳃可能是暴露于纳米 ZnO 的靶组织，而对块状 ZnO 来说，靶组织可能是肠道。此外，50mg/L 的纳米 ZnO 引起的组织病理变化比相同浓度的块状 ZnO 更为严重，这与细胞内氧化应激水平升高的诱导一致。还评估了溶解 Zn 离子的影响，结果表明离子毒性在此可忽略不计。本研究结果表明，纳米 ZnO 的观察到的毒性可能不是仅仅由颗粒溶解引起的，而是颗粒毒性和尺寸依赖性的结果。纳米 ZnO 的主要毒性机制可能是通过增加细胞氧化应激反应。
