Efeito da mistura dos metais zinco e níquel em diferentes salinidades sobre o microcrustáceo Artemia sp

Abstract

Marine pollution, caused for the human lifestyle modernization, include a range of contaminants that although almost always have terrestrial origin, often have the sea as their final destination. Among these pollutants, heavy metals are noted for having high toxicity and persistence. Toxicity studies commonly based on the exposure of organisms to stressors isolated under controlled conditions. In this sense, the aim of this work is to evaluate the toxicity of the heavy metals zinc and nickel isolated and combined in the microcrustacean Artemia sp. in the salinities 10, 17 and 35. The result of exposure of individual metals revealed that zinc was more toxic than nickel at all salt levels and the LC50 were 0,04, 0,18, 0,38 e 0,27, 0,29, 0,71 g/L for zinc and nickel in the salinities 10, 17 and 35, respectively. There was no statistical difference between lethal concentrations of both metals in all the salt levels, with the exception of zinc in salinity 10. The exposure data were worked in the graphic isobologram and in the method MIXTOX that use the conceptual models Concentration Addition and Independent Action (IA). In salinity 35, the isobologram showed antagonism for all the combinations, but with proximity to the effect additive, while the models IA and CA indicated addiction en salinity 17. The method MIXTOX and the isobologram showed the same metals mixture response, the antagonism, the best fit data occurred in the CA model in salinity 10. Thus, Artemia sp. was very resistant to the metals zinc and nickel. It was concluded, therefore, that the metal mixture tends to be antagonistic with the decrease of salinity.