Assessment of the aquatic environmental risk of the mixture of two commercial herbicides in the bioindicator Daphnia magna (#2012)

Authors

Susanivar Agustin, Maximiliano

Alvariño Flores, Lorena

Iannacone Oliver, Jose Alberto

Abstract

The bioassay with the bioindicator Daphnia magna, facilitates obtaining the individual and mixed acute ecotoxicological effect of various toxic chemicals through the mean lethal concentration (LC50). The objective of the present investigation was to evaluate the aquatic environmental risk of the mixture of herbicides, glyphosate (GLY) and paraquat (PQ) in D. magna. For the 24 and 48 h exposure tests, standardized cultures of D. magna were used. The herbicides GLY and PQ, and the mixture of both, were evaluated. The results obtained for D. magna showed that the acute toxicity was the following: mixture of GLY + PQ > PQ > GLY. The Aquatic Environmental Risk Assessment (ERA) without the use of the safety factor (FS) showed that GLY does not represent an individual risk in avocado cultivation. At the same time, it presents an aquatic risk in the other two scenarios (coffee and sugar cane). On the other hand, the PQ presents an environmental risk for all three scenarios. The ERA using FS showed the risk for both herbicides in the three scenarios. It is concluded that GLY and PQ cause a risk to the aquatic environment.