纳米ZnO和纳米CuO在斑马鱼体内的富集与清除

为探讨工程纳米材料的生物毒性,采用半静态暴露方式(更换试液周期为1 d),在4 mg·L-1和10 mg·L-1浓度条件下,进行了斑马鱼(Danio rerio)对2种金属氧化物纳米材料——nano-Zn O和nano-Cu O的富集和清除实验。整个实验为期52 d,其中暴露阶段28 d,清除阶段24 d。通过测定不同时间节点纳米材料在鱼体内的浓度,研究了斑马鱼对nano-Zn O和nano-Cu O的富集与清除规律;并计算暴露阶段的最大富集系数(BAFmax)以及清除阶段的排出速率常数和总量清除率,比较分析了斑马鱼对这2种纳米材料的富集与清除能力。结果表明:在暴露阶段,nano-Zn O和nano-Cu O在斑马鱼体内的BAFmax分别为169.5和493.4(4 mg·L-1处理组)及168.4和298.6(10 mg·L-1处理组),二者在斑马鱼体内均不具有生物蓄积性;在清除阶段,nano-Cu O可以被斑马鱼有效地排出,其总量清除率(99.5%)和排出速率常数均高于nano-Zn O,而直到清除24 d时,斑马鱼对nano-Zn O的清除仍不完全(清除率91%)。本实验结果为金属氧化物纳米材料对水生生物的慢性毒理学研究提供了基础数据。

Accumulation and Elimination of Nano-ZnO and Nano-CuO in Danio rerio

A 52-day continuous semi-static (test media renewal daily) waterborne exposure experiment, including 28-day uptake phase and 24-day depuration phase, was conducted to assess the accumulation and elimination of nano-ZnO and nano-CuO in zebrafish (Danio rerio) exposed to low concentration (4 mg?L^-1 and 10 mg?L^-1). The profiles of accumulation and elimination of nano-ZnO and nano-CuO in zebrafish were investigated by measuring the body burden of nanoparticles in fish tissues. And the abilities of accumulation and elimination of two nanomaterials were comparatively analyzed through calculating the maximum biaoaccumulation factors (BAFmax), depuration rate coefficient and elimination rate of total contents in fish body. The results showed that a certain amount of nano-ZnO and nano-CuO could be found in fish body with the BAFmax of 169.5, 493.4 for 4.0 mg?L^-1 treatment groups and 168.4, 298.6 for 10.0 mg?L^-1 treatment groups, respectively. Therefore, neither nano-ZnO nor nano-CuO was considered as bioaccumulative substances. In the elimination phase, accumulated nano-CuO in fish body could be depurated efficiently at 24 d post-exposure with the higher elimination rate (>99.5%) and depuration rate coefficient. However, the elimination of nano-ZnO from zebrefish was incomplete until 24 d post-exposure (elimination rate<91%). The experimental results provide basic data for the chronic toxicology research on metal oxide nanomaterials to aquatic organisms.