Ecological risk assessment of current-use pesticides and biocides in soils, sediments and surface water of a mixed land-use basin of the Pampas region, Argentina

The present study aimed to assess the ecological risk of 30 current-use agricultural pesticides and biocides in the soil, sediments and aquatic organisms of a mixed land-use basin located in the Depressed Pampas Region of Argentina. Risk Quotients (RQs) were used to evaluate the chronic risk in soil and aquatic organisms, while Toxic Units (TUs) were used to assess the acute risk in sediment-dwelling organisms and aquatic biota. Acetochlor, hydroxy-atrazine, glyphosate, AMPA, metolachlor, imidacloprid and tebuconazole were the only pesticide residues detected (>30%) and quantified in all the matrices evaluated. Glyphosate and AMPA showed the highest concentrations, being their mean and maximum levels 27.90–176.00 μg kg−1 and 270–712.50 μg kg−1 in soils, 8.28–32.0 μg kg−1 and 6.85–17.50 μg kg−1 in sediments, and 1.88–4.36 μg L−1 and 0.66–1.03 μg L−1 in surface water. The RQs in soils showed high chronic risk, mainly due to AMPA and imidacloprid. The TUs in sediments showed acute risk in dwelling organisms, mainly due to glyphosate and imidacloprid. RQs assessment showed a range of chronic risk levels according to the site/sampling event, with higher contribution of atrazine and its metabolites, and acetochlor, whereas TUs assessment showed no acute risk in aquatic biota. In contrast to Europe, in Argentina, there are no restrictions regarding the use of atrazine, acetochlor, imidacloprid and glyphosate to protect aquatic life. Thus, it is recommended that the current Argentine pesticide regulations should be modified to prevent ecological risk and protect ecosystems.Fil: Pérez, Débora Jesabel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Iturburu, Fernando Gastón. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Calderon, Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata. Facultad de Arquitectura, Urbanismo y Diseño. Instituto de Hábitat y Medio Ambiente; ArgentinaFil: Oyesqui, Lía A. E.. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: de Gerónimo, Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Aparicio, Virginia Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible - Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible; Argentin