Monitoramento de multiresíduos de agrotóxicos em matrizes ambientais

Abstract

Agriculture is responsible for providing food to the population and to contain pests that affect agricultural production, pesticides are commonly used. Brazil is among the largest pesticide consumers in the world and at the state level, Rio Grande do Sul occupies the top positions in pesticide consumption among Brazilian states. This is because both the state and the country have a large part of the economy based on grain production. However, the exacerbated use of pesticides is also responsible for several negative effects, such as the contamination of environmental matrices. Thus, the aim of the study was to investigate the presence of multi-residue pesticides in water from public underground water supply wells and dams, soil and sediment, in the municipality of Mato Queimado – RS. The samplings were carried out during the two-year period, 2019-2020, where 24 pesticides were monitored in the water samples, and in the period of three seasons of 2020, 18 pesticides were monitored in the soil and sediment, among them: 2,4- D, atrazine, azoxystrobin, bentazone, carbofuran, cyproconazole, clomazone, difenoconazole, epoxiconazole, fipronil, imazapique, imazethapyr, malathion, metsulfuron-methyl, penoxsulam, pyraclostrobin, pyrazosulfuron-ethyl, prophenothia, pyrazole, and trifloxystrobin, determined by means of liquid chromatography coupled with mass spectrometry (LCMS). 17 compounds were quantified in groundwater samples at concentrations from 0.01 to 11.73 µg L-1 , 16 compounds in surface water, at concentrations from 0.01 to 66.92 µg L-1 , 5 compounds in soil samples, at concentrations from 5.21 to 163.42 µg kg-1 , and 1 compound in sediment samples, at concentrations from 12.85 to 14.93 µg kg-1 . Regarding Brazilian legislation, Ordinance GM/GM No. 888/2021 of the Ministry of Health (MS) on water potability, only fipronil was above the maximum value allowed for water for human consumption. Therefore, this study is a contribution to society, as now, they will have information on the monitoring of pesticides in local waters, soils and sediments.