Effects Of Rees On Development Of Zebrafish (Danio Rerio) Embryos

REE compounds frequently have valuable catalytic, chemical, electrical, metallurgical, nuclear, magnetic, and optical properties. Therefore, they are widely used in many fields. With the wide applications and mineral exploitation of REEs, REEs will inevitably enter the environment, especially aquatic environment. Their potential effects on aquatic species have recently attracted much attention. So far, rare earth elements have not been proved to be one of the essential elements of the human body, the REE may enters the body through the food chain, thus accumulation effect influence on human health. In recent years, domestic and foreign have conducted fruitful research about the toxicity of rare earth elements. However, there is almost no report about the effects of the rare earth ions on the development of zebrafish embryos.The aim of this study was to determine the developmental toxicity rare earth elements on the growing zebrafish embryos, and discussion the action mechanism of the corresponding. Our study includes the 25nm CeO₂ was composed with liquid precipitation synthesis, and using the methods TEM, BET and DLS to characterize; after that studied the effect of rare earth oxide nanoparticles on the zebrafish embryonic hatch rates. At last, there were investigated different concentrations of rare earth ions, the toxicological endpoints included hatch rates at 72h, larvae mortality, body length and the medium lethal concentration (LC50) at 96h; and compared with the common heavy metal ions, such as Cd2+ and Cu2+.The results show that the 25nm CeO₂ which was composed with liquid precipitation synthesis compared with the commodity nanoscale CeO₂, has uniform particle size; the effect of the rare earth oxide nanoparticles to zebrafish embryonic hatch rates was more faint; REE3+ delayed zebrafish embryo and larval development, decreased survival and hatching rates, and caused tail malformation in a concentration-dependent way. Moreover, heavy rare-earth ytterbium led to more severe acute toxicity of zebrafish embryo than light rare-earth lanthanum. Compared to the common heavy metal pollutants Cu and Cd, REEs caused lesser acute toxicity to zebrafish embryos.