Centre for Nanobiotechnology, VIT University, Vellore 632014, India.
Ecotoxicol Environ Saf. 2012 Oct;84:70-7. doi: 10.1016/j.ecoenv.2012.06.015. Epub 2012 Jul 21.
This study on a microcosm, brings out the temporal changes in physico-chemical behavior of aluminum oxide nanoparticles (for a period of 210 days), at environmentally relevant concentrations (1000 μg/L and below). The dynamics of particle behavior in terms of mean hydrodynamic diameter, specific surface area and dissolution of soluble aluminum and, their possible ecological implications have been presented in this study. A thorough statistical analysis brings out nanoparticle behavior, where a rapid aggregation of particles (79±13 nm at 0 h to 1464±80 nm at 48 h), with a decrease in specific surface area (32 m2/g at 0 h to 1.7 m2/g at 48 h) was observed. Ion release profile indicated a significant increase in soluble aluminum concentration only after 36 h (277±15 μg/L at 0 h to 462±3 μg/L at 36 h) which reduced over a period of 60 days (279±20 μg/L). A differential response at 1000 μg/L concentration was observed, short term exposure (5 days) showed an immediate effect on the resident algal population (∼25% decreased viability) and the long term (7 months/210 days) exposure showed a gradual recovery. Thus, nanomaterials may not have the stipulated toxic response, at low concentration and longer standing period, presumably owing to the complexity of the natural systems.
本研究从微观角度揭示了在环境相关浓度（1000μg/L 及以下）下，氧化铝纳米颗粒在 210 天内的物理化学行为的时间变化。本研究提出了颗粒行为在平均水动力直径、比表面积和可溶性铝溶解方面的动态及其可能的生态影响。彻底的统计分析揭示了纳米颗粒的行为，其中颗粒迅速聚集（0 小时时的 79±13nm 到 48 小时时的 1464±80nm），比表面积减小（0 小时时的 32m2/g 到 48 小时时的 1.7m2/g）。离子释放曲线表明，仅在 36 小时后可溶性铝浓度才显著增加（0 小时时的 277±15μg/L 到 36 小时时的 462±3μg/L），在 60 天的时间内减少（279±20μg/L）。在 1000μg/L 浓度下观察到不同的反应，短期暴露（5 天）对当地藻类种群立即产生影响（活力降低约 25%），而长期暴露（7 个月/210 天）则逐渐恢复。因此，纳米材料在低浓度和较长时间内可能没有规定的毒性反应，这可能是由于自然系统的复杂性。
