†Institute of Environmental Sciences (CML), Leiden University, 2300 RA Leiden, South Holland, The Netherlands.
‡National Institute of Public Health and the Environment, Center for the Safety of Substances and Products, 3720 BA Bilthoven, Utrecht, The Netherlands.
Environ Sci Technol. 2015 Apr 7;49(7):4657-64. doi: 10.1021/acs.est.5b00538. Epub 2015 Mar 27.
There is increasing recognition that the wide use of nanoparticles, such as Cu (CuNPs) and ZnO nanoparticles (ZnONPs), may pose risks to the environment. Currently there is insufficient insight in the contribution of metal-based nanoparticles and their dissolved ions to the overall toxicity and accumulation. To fill in this gap, we combined the fate assessment of CuNPs and ZnONPs in aquatic test media with the assessment of toxicity and accumulation of ions and particles present in the suspensions. It was found that at the LC50 level of Daphnia magna exposed to the nanoparticle suspensions, the relative contributions of ions released from CuNPs and ZnONPs to toxicity were around 26% and 31%, respectively, indicating that particles rather than the dissolved ions were the major source of toxicity. It was additionally found that at the low exposure concentrations of CuNPs and ZnONPs (below 0.05 and 0.5 mg/L, respectively) the dissolved ions were predominantly accumulated, whereas at the high exposure concentrations (above 0.1 mg/L and 1 mg/L, respectively), particles rather than the released ions played a dominant role in the accumulation process. Our results thus suggest that consideration on the contribution of dissolved ions to nanoparticle toxicity needs to be interpreted with care.
人们越来越认识到，广泛使用纳米颗粒，如铜（CuNPs）和氧化锌纳米颗粒（ZnONPs），可能会对环境造成风险。目前，对于金属基纳米颗粒及其溶解离子对整体毒性和积累的贡献，了解还不够充分。为了填补这一空白，我们将铜纳米颗粒和氧化锌纳米颗粒在水生测试介质中的归宿评估与悬浮液中存在的离子和颗粒的毒性和积累评估结合起来。结果发现，在暴露于纳米颗粒悬浮液的大型溞 LC50 水平下，从 CuNPs 和 ZnONPs 释放的离子对毒性的相对贡献分别约为 26%和 31%，表明颗粒而不是溶解离子是毒性的主要来源。此外，还发现，在 CuNPs 和 ZnONPs 的低暴露浓度（分别低于 0.05 和 0.5 mg/L）下，溶解离子主要被积累，而在高暴露浓度（分别高于 0.1 和 1 mg/L）下，颗粒而不是释放的离子在积累过程中起主导作用。因此，我们的研究结果表明，对溶解离子对纳米颗粒毒性的贡献的考虑需要谨慎解读。
