title: Multi-residue determination and ecological risk assessment of pesticides in the lakes of Rwanda.
abstract: BACKGROUND
  To boost agricultural productivity for both domestic and export purposes, agricultural inputs such as pesticides are being promoted in Rwanda. Even though the use of pesticides is important for agriculture, their residues eventually end up in different environmental compartments and may negatively affect the environment. The purpose of this study was to determine the level of knowledge and awareness of the smallholder farmers towards the use of pesticides in Rwanda and to evaluate the ecological risks of pesticides in the surface water and in the vertical profile of Lake Kivu.
  
  
  RESULTS
  Based on the collected data, a method to monitor 33 currently used pesticides was developed. No contamination of the lower water layer was found, indicating that the groundwater that flows into Lake Kivu has not been polluted. Of the pesticides in the surface water, malathion exceeded the risk thresholds and posed a risk towards arthropods.
  
  
  CONCLUSIONS
  The results of this study show that there is a lack of farmer's awareness towards the hazards of pesticides when working with these compounds. Farmers in Rwanda are in need of specialised stewardship for pesticide application training and guiding services. Surface water has been contaminated with malathion, metalaxyl and carbendazim which were the most used pesticides by the farmers in the environment.
authors.affiliation: Ghent University, Faculty of Bioscience Engineering, Department of Crop Protection, Laboratory of Crop Protection Chemistry, Ghent, Belgium. Electronic address: Michael.houbraken@ugent.be.
authors.forename: Michael
authors.initials: M
authors.lastname: Houbraken
authors.affiliation: Ghent University, Faculty of Bioscience Engineering, Department of Crop Protection, Laboratory of Crop Protection Chemistry, Ghent, Belgium.
authors.forename: Valens
authors.initials: V
authors.lastname: Habimana
authors.affiliation: Ghent University, Faculty of Bioscience Engineering, Department of Crop Protection, Laboratory of Crop Protection Chemistry, Ghent, Belgium.
authors.forename: David
authors.initials: D
authors.lastname: Senaeve
authors.affiliation: Ghent University, Faculty of Bioscience Engineering, Department of Crop Protection, Laboratory of Crop Protection Chemistry, Ghent, Belgium.
authors.forename: Edelbis
authors.initials: E
authors.lastname: López-Dávila
authors.affiliation: Ghent University, Faculty of Bioscience Engineering, Department of Crop Protection, Laboratory of Crop Protection Chemistry, Ghent, Belgium.
authors.forename: Pieter
authors.initials: P
authors.lastname: Spanoghe
mesh_terms: D000383:Agriculture; D004784:Environmental Monitoring; D060106:Lakes / Q000737:chemistry*; D010575:Pesticides / Q000032:analysis*; D018570:Risk Assessment; D012432:Rwanda; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D010575:Pesticides; D014874:Water Pollutants, Chemical
keywords: Lake Kivu; Lake Mugesera; Lake Muhazi; Risk assessment; Rwanda; Sensitivity distributions; Species