Characterization of Urban and Horticultural Pesticide Profiles in Surface Water Bodies Impacted by Horticultural and Urban Activities in the Greater La Plata Area

RICARDO ANDRÉS ROSERO; TOMÁS MAC LOUGHLIN; MARÍA LETICIA PELUSO; MANUEL FLORES; JESICA SANSIÑENA; JUAN CARLOS CASAS; JOSÉ DAMIÁN MARINO

Montevideo

Congreso; SETAC Latin America 15th Biennial Meeting; 2023

urban activities. For this purpose, two monitoring campaigns were carried out in which samples of surface water were collected, filtered by 0.45μm, and extracted by sonication, while the soluble fraction was extracted using SPE. The extracts were analyzed by LC-MS/MS using 4 isotopic tracers. Out of a total of 70 pesticides studied, 39 compounds were detected in water (1 synergist, 16 herbicides, 14 insecticides, and 8 fungicides) in a concentration range between LD to 27.09 μg mL-1 during the first campaign, and 21 were detected in suspended particulate matter (1 synergist, 6 herbicides, 6 insecticides and 8 fungicides) in a concentration range between LD to 2.06 μg mL-1. For the second campaign, there was a decrease in the pesticides present, with 29 compounds detected in water (1 synergist, 12 herbicides, 8 insecticides and 8 fungicides) in a concentration range between LD to 16.45 μg mL-1, and 18 detected in suspended particulate matter (1 synergist, 4 herbicides, 4 insecticides, and 9 fungicides) in a concentration range between LD to 5.86 μg mL-1. The most commonly detected compounds include the herbicides Metolachlor and 2,4-D, the insecticides Imidacloprid and Chlorpyrifos Ethyl, and the fungicide Azoxystrobin, which were associated with the water column and present in all 7 streams studied. In suspended particulate matter, the insecticides Chlorpyrifos and Imidacloprid were most commonly found (found in 100% and more than 57% of streams respectively), along with the herbicide Prometryn, present in more than 70% of the water bodies. The number of pesticides detected is similar in all streams, however, the concentrations found in streams with agricultural influence for many of these compounds are higher compared to streams that only pass through urban areas.[Ja1] This study contributes to expanding the information on the presence and amount of these compounds associated with surface water sources and the impact generated by horticultural activities mainly in the increase of environmental concentrations.