The Effects Of Nitrobenzene On The Embryo Development Of Bighead, Silver Carp And Cell DNA Of Zebrafish

Nitrobenzene, C6H5NO2, is an important chemical raw material and widely used in national defense, dyeing and printing, plastics, pesticides and pharmaceutical industry. There is about 10,000 tons nitrobenzene compounds discharged into the environment each year in the world, is one of the major organic pollutants now. NB is weak mutagenicity that long-term exposure to humans and plants and animals will result in great harm. With the rapid development of the chemical industry, more and more nitrobenzene was discharged into the middle reaches of the Songhua River in China, cause deterioration of water quality and affect the aquatic ecosystems, also enriched in the organism and may be endanger to human health.This paper selected contaminant nitrobenzene (NB) as resaerch object, use laboratory simulation of embryos hatching and single-cell gel electrophoresis technique, studied the effect of NB on the silver carp, bighead carp embryonic development and DNA damage of the zebrafish liver and pancreas, kidney, fin, sperm cell. Moreover, this paper tried to probe into the effect mechanism of NB. Which provided the basis for the fully estimate of ecological toxicology on aquatic organism. The results showed that:1. Silver carp embryos that exposed to different concentrations of nitrobenzene compare to the control group showed different mortality and abnormality rate, and development was delayed. With increasing concentration of nitrobenzene, embryo mortality and abnormality rate upward trend, when exposed concentration> 0.85 mg?L-1, mortality reached 100%. embryonic development delayed for 3 to 16 h at the concentration of 0.017 ~ 0.425 mg?L-1, and embryos were all dead at 32 h exposure to the concentration of 0.85 mg?L-1 and 1.7 mg?L-1 .2. Bighead carp embryos that exposed to different concentrations of nitrobenzene compare to the control group showed different mortality and deformity rate, and development was delayed too. With increasing concentration of nitrobenzene, embryo mortality and abnormality rate upward trend, when exposed concentration> 0.85 mg?L-1, mortality reached 100%. embryonic development delayed for 4 to 8 h at the concentration of 0.017 ~ 0.425 mg?L-1, and embryos were all dead at 25 h exposure to the concentration of 0.85 mg?L-1 and 1.7 mg?L-1 .3. Certain concentration of nitrobenzene induced DNA damage on cell of zebrafish liver and pancreas (0.106 ~ 1.7 mg?L-1), kidney (0.017 ~ 1.7 mg?L-1), fins (0.017 ~ 1.7 mg?L-1), sperm (0.106 ~ 1.7 mg?L-1). Injured cells and the average tail length increased with the concentration of nitrobenzene. Distribution of cell changed with the increase of concentration, 0,1grade damage cell dominant into 2,3 grade damage cell dominant.Sum up, NB can make silver, bighead carp embryonic development delay, and may result in the development of fetal death and abnormality fries. NB also induced DNA damage on the liver and pancreas, kidney, fin, sperm cells of Zebrafish, showed genetic toxicity.