The Effect of Gadolinium and Lanthanum on the Mortality ofDaphnia magna

Rare earth elements (REEs) have been recently identified as emergent contaminants because of their numerous and increasingapplications in technology. The impact of REEs on downstream ecosystems, notably aquatic organisms, is of particular concern, but has to date been largely overlooked. The purpose of this study were to generate toxicological information regarding thesepoorly studied Gadolinium and Lanthanum elements to determine the current risk associated with these elements. The results of this work indicate notable D. magna mortality in high concentration of La and Gd. The highest mortality rate was determined as100% at 100 mg/L concentration for both La and Gd at the end of the 24hour . At the end of the 48 hours, the highest mortalityrate for both La and Gd was observed at 100 mg/L concentration. No mortality was determined at 48 hours at a concentration of10 mg/l Gd. 100% mortality was observed for two elements at 50 and 100 mg/L concentrations at 72 hours. in the natural living water no death was seen in this time period. The findings from our study also indicate that Gd is more toxic than La. Due to thismortality effect of La and Gd to D. magna, it will be important for the ensuring continuity of the ecosystem to monitor especiallyaquatic environments and to treat them with appropriate treatment methods from contaminated environments.