三种金属氧化物纳米颗粒的水生态毒性

参考国际经济合作与发展组织(OECD)化学品生态毒性测试标准方法,以绿藻(Scenedesmus oblignus)和大型蚤(Daphnia magna)为受试生物,研究了3种金属氧化物纳米颗粒(纳米氧化锌nZnO、纳米二氧化钛nTiO2、纳米氧化铝nAl2O3)水悬浮液的水生生态毒性.结果发现,不同的纳米颗粒具有不同的毒性:nZnO、nTiO2和nAl2O3对斜生栅藻生长的 96 h半效应浓度(EC50)值分别为1.049、15.262、>1000 mg · L-1,而对大型蚤活动抑制的 48 h EC50 值则分别为0.622、35.306 mg · L-1和114.357 mg · L-1.据此可得到3 种金属氧化物纳米颗粒水悬浮液的毒性大小顺序为:nZnO ＞nTiO2 ＞ nAl2O3.此外,不同的生物对金属氧化物纳米颗粒的敏感性也不同,除nTiO2以外,大型蚤对另外2种纳米颗粒的敏感性强于斜生栅藻.实验结果表明,人工纳米材料的生态毒性和环境效应不容忽视,应重视并深入研究此类纳米材料的毒性作用机制和影响因子,以便能对其进行更好的风险管理.

Aquatic ecotoxicities of nanoscale TiO2, ZnO and Al2O3 water suspensions

The ecotoxicity of nanoscale TiO2, ZnO and Al2O3 water suspensions was examined using a method developed based on the standard OECD Guidelines for the Testing of Chemicals (i.e. OECD 201,202). The green algae (Scenedesmus obliquus) and the water-flea (Daphnia magna) were used as the testing organisms. The results showed that different nanoparticles exhibited different toxicities to the testing organisms. The 96 h EC50 of nZnO, nTiO2 and nAl2O3 on the growth of Scenedesmus obliquus were 1.049, 15.262 mg?L-1 and >1000 mg?L-1, respectively. The 48 h immobilization EC50 of nZnO, nTiO2 and nAl2O3 on Daphnia magna were 0.622, 35.306 mg?L-1 and 114.357 mg?L-1, respectively. Based on the results, their toxicity rank as nZnO > nTiO2 > nAl2O3. The toxicity results indicate that such nanoparticles might pose potential environmental impact. Further research on the ecotoxicological mechanisms of such nanoparticles is warranted in order to minimize the adverse ecological effects and human health risk of nanotechnology development.