Pesticides in Aquatic Ecosystems in the Andean Region of South America: Occurrence and Ecological Risk Assessment in the Uco Valley (Mendoza, Argentina).

ITURBURU FERNANDO GASTÓN; BERTRAND, LIDWINA; SOURSOU, VASILIKI; SCHEIBLER, ERICA; CALDERON GABRIELA; AMÉ MARIA VALERIA; ALTAMIRANO, JORGELINA; MENONE MIRTA LUJÁN; PICÓ, YOLANDA

Conferencia; SETAC Europe 33rd Annual Meeting; 2023

Chemical pollution constitutes one of the major drivers of biodiversity loss in freshwater ecosystems. It has been widely demonstrated that pesticides can reach aquatic ecosystems and affect the species that inhabit them. In Argentina, the major agriculture production is related to extensive crops (e.g. soybean, corn, wheat) and the pesticides monitoring efforts are mostly focused on water bodies related to agroecosystems located in the plains of Pampas region. However, there are other regional crops with economic relevance that include different management strategies and occur in ecosystems with differential climatic and hydrogeological characteristics. This is the case of the Uco Valley (Mendoza province, Argentina) in the Andean mountains, with highly technified production of vine, fruits and vegetables, but with scarce information on its environmental effects on water bodies. In this context, this study aimed on quantify pesticides in aquatic ecosystems of the Uco Valley and on develop an ecological risk assessment (ERA). For this purpose, two sampling campaigns (spring/ summer) in five sites with different land uses were carried out. Surface water samples were obtained (by triplicate) and current use pesticides were extracted with SPE columns and quantified with UPLC-MS/MS. A total of 72 analytes (pesticides and metabolites) were studied, and risk quotients (RQs) were calculated for each site/season. Several herbicides, fungicides and insecticides were detected in the different sites, with different patterns likely related to land use and hydrological conditions of water courses. A total of 16 analytes were detected, being atrazine and atrazine-deisopropyl, carbendazim, DMA, imidacloprid, tebuconazole, terbuthylazine-2-hydroxy and terbutryn the most ubiquitous. The RQs calculation showed that the pesticides reported in the Uco Valley could implicate medium/ high risk on organisms inhabiting in its aquatic ecosystems. Particularly, the herbicide terbutryn and the fungicide carbendazim were the major contributors to risk and, in some cases, also the fungicides tebuconazole and difenoconazole and the insecticide diazinon. These results constitute, for the author’s knowledge, the first report of ERA for pesticides present in aquatic ecosystems of Uco Valley. The ecological risk assessment would be complemented with higher tier analysis, including different methodological approaches that include the evaluation of in situ effects on biological communities.