[Groundwater and rainwater contamination by pesticides in an agricultural region of Mato Grosso state in central Brazil].

This study sought to analyze groundwater and rainwater contamination by pesticides in two municipalities (Lucas do Rio Verde and Campo Verde) of Mato Grosso state. The area is Brazil's mid-west situated among the major soybean, corn and cotton producers in the state and the country. The analytical methodology combined chromatographic techniques on groundwater and rainwater samples with eco-toxicological analyses of the impacts of contamination by pesticide on bio-indicator species. The results revealed the presence of different pesticide residues in the groundwater and rainwater samples collected in the two municipalities. In conjunction with this data, results of the eco-toxicological tests revealed the presence of anomalies in a bio-indicator species collected in one of the two study sites compatible with exposure to pesticides. The results presented and discussed here highlight the degradation of water resources in the region, caused by the intensive use of pesticides in agriculture, including the contamination of drinking water sources and rain, broadening the risk of contamination beyond the cultivated areas.