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Soil, water, kales and tomatoes from Ewaso Narok wetland were collected during wet and dry seasons and analyzed for 15 pesticide residues. Multi-residues method (QuEChERS EN) was used for sample preparation and Liquid chromatography-tandem mass spectrometry (LC-MS/MS) used for analysis. The soil was highly contaminated compared to water, kales and tomatoes. Banned (Aldicarb, azinphos methyl) and restricted (diazinon, chlorpyrifos and fenpropathrin) pesticide residues were detected in sample matrices in different concentrations. Residues levels that exceeded the European Union (EU) maximum residues limit (MRLs) were found in kales (triadimefon, cyproconazole I and II, fenpropathrin), tomatoes (cyproconazole I and II, fenpropathrin and spiroxamine) and water (aldicarb). All the pesticide residues concentrations were within the recommended levels of the World Health Organization (WHO) and Agricultural Food Organization (FAO). Residue levels were significantly high in the upstream and midstream during wet and dry seasons. Temperatures, conductivity (EC), pH, salinity, total dissolved solids (TDS) and dissolved oxygen (DO) were measured to assess soil/water quality. All the physicochemical parameters were within the recommended levels. Though most residue levels were below the EU-MRLs, MCLs and within the toxicological levels (LD50), the negative effects of the long term exposure to the wetland biodiversity and human health are real and should not be ignored. Farmers need to embrace Good Agricultural Practices (GAP) in order to reduce over-reliance on pesticide use in the wetland.
Otieno PO, Lalah JO, Virani M, Jondiko IO, Schramm KW. Soil and water contamination with carbofuran residues in agricultural farmlands in Kenya following the application of the technical formulation Furadan. Journal of Environmental Science and Health. Part. B, Pesticides, Food Contaminants, and Agricultural Wastes. 2010;45(2):137–144.
Macharia I, Mithofer D, Waibel H. Potential environmental impacts of pesticides use in the vegetable sub-sector in Kenya. African Journal of Horticultural Science. 2009;2: 138–151.
Tiryaki O. The fate of pesticide in the environment. Journal of Biological and Environmental Sciences. 2010;4(10):29–30.
Davis A, Lewis S. Pesticide residues in waterways of the lower Burdekin region: Challenges in ecotoxicological interpretation of monitoring data. Journal of Ecotoxicology. 2008;14:89–108.
Galt RE. Scaling up political ecology: The case of illegal pesticides on fresh vegetables imported into the United States, 1996–2006. Annals of the Association of American Geographers. 2010;100(2):327–355.
Bajwa U, Sandhu KS. Effect of handling and processing on pesticide residues in food- A review. Journal of Food Science and Technology. 2014;51(2):201–220.
Tefera AT, Murty ASN. Effects of droughts on rain-fed agriculture in a changing climate: Case study of Arba Minch Zuriya District, Ethiopia. Imperial Journal of Interdisciplinary Research. 2016;2(5): 1866-1877.
Damalas CA, Eleftherohorinos IG. Pesticide exposure, safety issues, and risk assessment indicators. International Journal of Environmental Research and Public Health. Open Access. 2011;8(5): 1402-1419.
Tsimbiri PF, Moturi WN, Sawe J, Henley P, Bend JR. Health impact of pesticides on residents and horticultural workers in the Lake Naivasha region, Kenya. Scientific Research Publishing. 2015;24–34.
Njoroge S. Evaluating farmer’s knowledge in pesticide handling and determining pesticide levels in maize after various processing methods and different storage conditions. Thesis. Kenyatta University; 2009.
Gupta RC, Milatovic D. Organophosphates and carbamates. In Veterinary Toxicology (2nd Edition). Elsevier. 2012;573–585.
Kitonga LM, Moturi WN, Mwonga SM, Taabu I. Assessment of physico - chemical characteristics of groundwater among different farm sizes in Ainabkoi sub - county, Uasin Gishu County, Kenya. African Journal of Environmental Science and Technology. 2018;12(11):408–416.
WHO. Guidelines for drinking water quality: Fourth edition incorporating the first addendum. World Health Organization (WHO). 2017;1-541.
Lambropoulou DA, Konstantinou IK, Albanis TA. Determination of fungicides in natural waters using solid-phase microextraction and gas chromatography coupled with electron-capture and mass spectrometric detection. Journal of Chromatography A. 2000;893(1):143– 156.
Madrid Y, Zayas ZP, Danielson TJ, Ye M, Beach J, Martin JW, Senthilselvan A. Protocols for collecting water grab samples in rivers, streams, and freshwater wetlands. International Journal of Environmental Research and Public Health. 2014;26(4):6442–6471.
Hassaan M. Winkler method for DO determination. National Institute of Oceanography. ResearchGate. 0-1; 2016.
Water Corporation. QuEChERS procedure for multi-residue pesticide analysis -disQuE dispersive sample preparation. Waters - The Science of What’s Possible. USA. 2011;1-8.
Rizzetti TM, Kemmerich M, Martins ML, Prestes OD, Adaime MB, Zanella R. Optimization of a QuEChERS based method by means of central composite design for pesticide multiresidue determination in orange juice by UHPLC-MS/MS. Food Chemistry. 2016;196:25– 33.
Ferrer I, García-Reyes JF, Mezcua M, Thurman EM, Fernández-Alba AR. Multi-residue pesticide analysis in fruits and vegetables by liquid chromatography-time-of-flight mass spectrometry. In Journal of Chromatography A. 2005;1082:81–90.
AlMulla SAM. Determination of multiple pesticides residues in imported tea in UAE using liquid and gas chromatography and tandem mass spectrometry. Electronic Theses and Dissertations. United Arab Emirate University. 2016;1-198.
Kirianki PR, Muchiri E, Potgieter N. Physico-chemical quality of drinking water in the Njoro sub-county in Kenya. Journal of Water Sanitation and Hygiene for Development. 2018;497–507.
WHO. Guidelines for drinking-water quality: Fourth Edition. World Health Organization. Geneva, Switzerland. 2011;1-564.
Anwar T, Ahmad I, Tahir S. Determination of pesticide residues in soil of Nawabshah District, Sindh, Pakistan. Pakistan Journal of Zoology. 2012;44(1):87–93.
Silva V, Mol HGJ, Zomer P, Tienstra M, Ritsema CJ, Geissen V. Pesticide residues in European agricultural soils – A hidden reality unfolded. Science of the Total Environment. 2019;653:1532–1545.
Liu H, Lin T, Mao J, Lu H, Yang D, Wang J, Li Q. Paclobutrazol residue determination in potato and soil using low temperature partition extraction and ultrahigh performance liquid chromato-graphy tandem mass spectrometry. Journal of Analytical Methods in Chemistry. 2015;1–6.
Elgueta S, Moyano S, Sepúlveda P, Quiroz C, Correa A. Pesticide residues in leafy vegetables and human health risk assessment in North Central agricultural areas of Chile. Food Additives and Contaminants: Part B Surveillance. 2017;10(2):104–112.
Arjmandi R, Tavakol M, Shayeghi M. Determination of organophosphorus insecticide residues in the rice paddies. International Journal of Environmental Science and Technology. 2010;7(1):175–182.
El-Zaher TRA, Nasr IN, Mahmoud HA. Behavior of some pesticide residues in and on tomato and kidney beans fruits grown in open field. American-Eurasian Journal of Toxicological Sciences. 2011;3(3):213–218.
Lozowicka B, Abzeitova E, Sagitov A, Kaczynski P, Toleubayev K, Li A. Studies of pesticide residues in tomatoes and cucumbers from Kazakhstan and the associated health risks. Environmental Monitoring and Assessment. 2015;187(10): 1–19.
Moncada J. Spatial distribution of pesticide contamination potential around lake Naivasha, Kenya. Water Resourses Survey. 2001;1–110.
EFSA. The 2015 European Union report on pesticide residues in food. European Food Safety Authority (EFSA) Journal. 2017;15(4):1–134.
Watts M, Lee T, Aidy H. Pesticides and agroecology in the occupied west bank: Conclusions from a joint APN-PANAP mission in Palestine. Palestine. 2016;1- 24.
PAN. PAN International List of Highly Hazardous Pesticides (PAN List of HHPs). Pesticide Action Network International. Hamburg, Germany. 2015;1-38.
Henry L, Kishimba M. Levels of pesticide residues in water, soil and sediments from southern Lake Victoria and its basin. Tanzania Journal of Science. 2003;29(1): 1–89.
WHO. Aldicarb in drinking water background document for development of WHO Guidelines for Drinking-water Quality. World Health Organization. 2003;2:1–14.
Musa S, Gichuki JW, Raburu PO, Aura CM. Organochlorine and organophosphorus pesticide residues in water and sediment from Yala/ Nzoia River within Lake Victoria Basin, Kenya. Journal of Ecology and the Natural Environment. 2011;3(12):392–399.
Golge O, Kabak B. Evaluation of QuEChERS sample preparation and liquid chromatography–triple-quadrupole mass spectrometry method for the determination of 109 pesticide residues in tomatoes. Food Chemistry. 2015;176:319-332.