Runoff-Related Pesticide Input into the Lourens River, South Africa: Basic Data for Exposure Assessment and Risk Mitigation at the Catchment Scale

摘要: The characterization of runoff-related pesticide input and the identification areas concern in field are essential for a comprehensive assessment risk planning mitigation measures. To this end, agriculturally-derived aqueous particle-associated contamination Lourens River its tributaries was measured design. Sampling performed beginning April prior to first rainfall wet season middle during high water conditions following 9.6 mm d-1. Pre-runoff samples indicated with endosulfan at levels up 0.06 μg L-1, while no other pesticides were detectable. Rainfall-induced runoff resulted an increase endosulfan, deltamethrin, azinphos-methyl, chlorpyrifos, procymidone 0.35, 1.4, 0.6, 0.19 9 respectively samples. Endosulfan, chlorpyrifos detected maximum concentrations 273, 152, 245 kg-1 suspended sediments. No increased control site upstream agricultural area. received via discharging surrounding farming Contamination six depended on landuse slope characteristics enabled target sites reduction approaches. Transient exceeded quality limit proposed by South African Department Water Affairs Forestry (DWAF). downstream area has been identified as where potential toxic could arise.