Pesticides applied in paddy rice can be transported to water bodies. The determination of the contamination extent is very important to alert the society and the politicians about the contamination issue. The objective of this study was to monitor pesticides in surface water in seven regions of south Brazil associated with the rice cropping in three different moments of the 2007/2008 growing season. Surface water samples were collected at three locations per region, with a total of 21 locations. The pesticides evaluated were: clomazone, quinclorac, penoxsulam, imazethapyr, imazapic, carbofuran, 3-hydroxy-carbofuran, fipronil and tebuconazole. The samples were analyzed by LC-MS/MS. Imazethapyr, carbofuran and fipronil were detected in all regions studied. A higher number of pesticides were detected in the 'Depressão Central' and in the 'Planície Costeira Externa à Lagoa dos Patos' regions, with eight pesticides. The 'Região Sul' had the lowest contamination, with detection of only four pesticides in surface water. All samples in all season contained at least one pesticide.
contamination; environmental fate; pesticide dispersion; residues
