title: Impacts of nutrients and pesticides from small- and large-scale agriculture on the water quality of Lake Ziway, Ethiopia.
abstract: The area around Lake Ziway in Ethiopia is going through a major agricultural transformation with both small-scale farmers and large horticultural companies using pesticides and fertilisers at an increased rate. To be able to understand how this influences the water quality of Lake Ziway, water quality data was gathered to study the dynamics of pesticide concentrations and physicochemical parameters for the years from 2009 to 2015. Results indicate that for some physicochemical parameters, including pH, potassium and iron, over 50 % of the values were above the maximum permissible limit of the Ethiopian standard for drinking water. The fungicide spiroxamine poses a high chronic risk when the water is used for drinking water, while the estimated intake of diazinon was approximately 50 % of the acceptable daily intake. Higher-tier risk assessment indicated that the fungicide spiroxamine poses a high acute risk to aquatic organisms, while possible acute risks were indicated for the insecticides deltamethrin and endosulfan. Longer-term monitoring needs to be established to show the water quality changes across time and space, and the current study can be used as a baseline measurement for further research in the area as well as an example for other surface water systems in Ethiopia and Africa.
authors.affiliation: Department of Aquatic Ecology and Water Quality Management, Wageningen University, Wageningen University and Research Centre, P.O. Box 47, 6700 AA, Wageningen, The Netherlands.|The College of Natural Sciences, University of Addis Ababa, Arat Kilo campus, Addis Ababa, Ethiopia.
authors.forename: Berhan M
authors.initials: BM
authors.lastname: Teklu
authors.affiliation: Horn of Africa Regional Environment Centre and Network, Addis Ababa University, P.O. Box 80773, Addis Ababa, Ethiopia.
authors.forename: Amare
authors.initials: A
authors.lastname: Hailu
authors.affiliation: Horn of Africa Regional Environment Centre and Network, Addis Ababa University, P.O. Box 80773, Addis Ababa, Ethiopia.
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Wiegant
authors.affiliation: Department of Aquatic Ecology and Water Quality Management, Wageningen University, Wageningen University and Research Centre, P.O. Box 47, 6700 AA, Wageningen, The Netherlands.
authors.forename: Bernice S
authors.initials: BS
authors.lastname: Scholten
authors.affiliation: Department of Aquatic Ecology and Water Quality Management, Wageningen University, Wageningen University and Research Centre, P.O. Box 47, 6700 AA, Wageningen, The Netherlands. paul.vandenbrink@wur.nl.|Alterra, Wageningen University and Research Centre, P.O. Box 47, 6700 AA, Wageningen, The Netherlands. paul.vandenbrink@wur.nl.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Van den Brink
mesh_terms: D000383:Agriculture; D059001:Aquatic Organisms / Q000187:drug effects; D003976:Diazinon / Q000032:analysis; D004726:Endosulfan / Q000032:analysis; D004784:Environmental Monitoring; D005002:Ethiopia; D060106:Lakes / Q000737:chemistry*; D009570:Nitriles / Q000032:analysis; D010575:Pesticides / Q000032:analysis* / Q000633:toxicity; D011722:Pyrethrins / Q000032:analysis; D018570:Risk Assessment; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000633:toxicity; D060753:Water Quality
chemical_list: D009570:Nitriles; D010575:Pesticides; D011722:Pyrethrins; D014874:Water Pollutants, Chemical; C017180:decamethrin; D004726:Endosulfan; D003976:Diazinon
keywords: Lake Ziway; Monitoring; Pesticides; Physicochemical parameters; Risk assessment; Water quality