Absorption of Europium chloride from zebrafish (Danio rerio) embryos under experimental conditions

Lanthanides (Ln) have an essential role in the pollution of the environment because of their ecotoxicity. The pollution of Ln significantly increased due to their use in industry and agriculture in the last decade. Europium (Eu) is the most reactive lanthanide by far. This metal is contained in many industries wastes and it may enter the food chain. The biochemical behavior of lanthanides has been extensively studied, but there are limited studies on Eu. It is remarkable that Ln react with biologically chemical compounds, affecting competitively and replacing the basic ions of the cell such as calcium (Ca2+) and magnesium (Mg2+). Based on the international literature, there are not much data on the toxic effects of Eu mainly on aquatic organisms. Exposure of zebrafish embryos to Europium indicated that the absorption of the metal from the embryos was taken place from the earliest stages of their development.