Research On Toxicology Of Nano-ZnO To Organism

With the production and popularity of nanomaterials, the occupational and environmental exposure is great increasing. Nanomaterials can enter into water during life cycle (production, store, transportation, consumption, treatment or recycle), cause water and sediments pollution, endanger aquatic ecosystems, and even bring a potential hazard on human health through food chain. So, it is need for toxicity studies on nanomaterials.Zinc oxide used as a sunscreen and food additives was chosen in this study. Acute toxicity of zinc oxide on rodents and its inhibitory to D. manga were studied in the paper. The result showed as follow:(1) Nanomaterials can aggregate with different degree in solvent. TEM images showed the aggregate 10±1 nm ZnO formed in physiological saline was the largest, about 0.5～1μm. The size of aggregate 25±5nm ZnO formed was the smallest, about 0.2μm. It is about 0.5～1μm for 90±10nm ZnO.(2) TP, ALB, LDH and BUN, CR showed 25±5 nm and 10±1nm ZnO may induce liver damage and renal dysfunction at the dose of 0.5g/kg bw. SOD and GSH-Px are antioxidant indicators and important enzymes to clear free radical. The mice exposed 0.5g/kg bw dose of 10±1nm ZnO had the lowest ability to clear free radical, that is, smaller sized ZnO particles led more serious oxidative damage at 0.5g/kg bw dose.(3) Tissue distribution of Zn showed ZnO nanoparticles can enter into circulatory system of organism.(4) Statistical Analysis indicated the impact of interaction of dose and size on zinc content in bone, spleen and kidney was not obvious, but it was significant in lung and pancreas (P<0.05). When the dose was 0.5g/kg bw, ZnO nanoparticles accumulated in lung, spleen (except for 10±1nm), kidney (90±10nm), pancreas (90±10nm) and bone, to different degree. At low dose, zinc content great decreased in 90±10nm and 10±1nm ZnO particles treatments.(5) Take daphnia magna as mode biololgy to study the toxicity affect of nano- ZnO at the time of its leak. The result showed the death reason was difference at its different states. When nano- ZnO was in suspending state, Daphnia Magna was died because of eating too much nano- ZnO or asphyxia as the low oxygen content.