Pesticides, Pharmaceuticals and Personal Care Products in Tres Arroyos Basin (Buenos Aires, Argentina): Sources, Occurrence and Ecological Risk Assessment.

ITURBURU, F. G.; BERTRAND, LIDWINA; LOMBARDERO, LUCAS RODRIGO; SOURSOU, V; AMÉ, M.V.; ALTAMIRANO. JORGELINA; PICÓ, YOLANDA; MENONE, MIRTA LUJÁN

Montevideo

Congreso; SETAC Latin America 15th Biennial Meeting; 2023

Human activities, both in rural or urban environments, are sources of chemical pollution mainly for aquatic ecosystems. Moreover, the presence of chemicals’ mixtures including compounds with different physicalchemical characteristics and mechanisms of action (pesticides, pharmaceuticals and personal care products (PPCPS), among others) has become a topic of interest not only for scientists, but also for regulatory authorities. In this context, the present study aimed on evaluate the presence, and possible sources of pesticides and PPCPs in different streams of Tres Arroyos basin, and to perform an ecological risk assessment. For this purpose, two sampling events (spring, summer) were carried out in five sites of three streams with different land use. Surface water samples were collected in triplicate for chemical analysis. Samples were filtered and solid phase extraction was performed. Chemical analysis was performed by high resolution liquid chromatography mass spectrometry. Risk assessment was performed using the Risk Quotients (RQ) approach, and SRQ was calculated both for pesticides and PPCPs. A total of 20 pesticide molecules were quantified, encompassing fungicides, herbicides, insecticides and metabolites,being atrazine and its metabolites, the fungicide carbendazim and the insecticide imidacloprid the most ubiquitous. The highest Spesticides concentrations were found in a fully rural environment (Primer Brazo, Claromecó stream) with extensive crop production (corn, wheat, sunflower), and without a clear temporal trend. Regarding risk assessment related to pesticides, ΣRQ showed a potential high risk for all the sites and sampling seasons, despite the land use. On the other hand, 18 PPCPs were quantified in the basin, with detection in all the sites and both seasons, but with a clear peak in Parque Cabañas site, related to wastewater treatment plant (WWTP) discharge. The main findings were the ubiquity of caffeine, the high concentrations of acetaminophen and ibuprofen, the detection of the plasticizer bisphenol A, and the first report of parabens in aquatic ecosystems in Argentina. Regarding risk of PPCPs, ΣRQs have shown the same pattern than quantified concentrations, with a clear peak in the site close to the WWTP. This study isthe first step in the evaluation of chemical risk assessment in the basin. Next step must involve evaluation of effects on aquatic organisms in situ.