Otieno P.O., Owuor P.O., Lalah J.O., Pfister G., Schramm K.-W.
Department of Chemistry, Maseno University, P.O. Box 333, 40105 Maseno, Kenya; Helmholtz Center Munich - German Research Center for Environmental Health (GmbH), Molecular EXposomics (MEX), Ingolstädter Landstr. 1, 85764 Neuherberg, Germany; TUM, Wissenschaftszentrum Weihenstephan fuer Ernaehrung und Landnutzung, Department fuer Biowissenschaften, Weihenstephaner Steig 23, 85350 Freising, Germany; Department of Chemical Sciences and Technology, Kenya Polytechnic University College, P.O. Box 42528, 00200-City Square Nairobi, Kenya
Otieno, P.O., Department of Chemistry, Maseno University, P.O. Box 333, 40105 Maseno, Kenya, Helmholtz Center Munich - German Research Center for Environmental Health (GmbH), Molecular EXposomics (MEX), Ingolstädter Landstr. 1, 85764 Neuherberg, Germany; Owuor, P.O., Department of Chemistry, Maseno University, P.O. Box 333, 40105 Maseno, Kenya; Lalah, J.O., Department of Chemical Sciences and Technology, Kenya Polytechnic University College, P.O. Box 42528, 00200-City Square Nairobi, Kenya; Pfister, G., Helmholtz Center Munich - German Research Center for Environmental Health (GmbH), Molecular EXposomics (MEX), Ingolstädter Landstr. 1, 85764 Neuherberg, Germany; Schramm, K.-W., Helmholtz Center Munich - German Research Center for Environmental Health (GmbH), Molecular EXposomics (MEX), Ingolstädter Landstr. 1, 85764 Neuherberg, Germany, TUM, Wissenschaftszentrum Weihenstephan fuer Ernaehrung und Landnutzung, Department fuer Biowissenschaften, Weihenstephaner Steig 23, 85350 Freising, Germany
This study reports evidence of increased chlorpyrifos contamination in sediment and water in Lake Naivasha following its intensive application in the horticultural farms in the catchment area. Analytical results show that levels of chlorpyrifos residues were influenced by climate-induced rainfall pattern with higher levels reported during period of heavy precipitation with significant decrease during low rainfall. On average, the levels ranged between 14.8 and 32.8 ng g-1 in sediment during rainy season compared to a range of 8.5-16.6 ng g-1 in the dry season. Additionally, the mean concentration of chlorpyrifos in water ranged between 8.61 and 22.4 μg L -1 during rainy season and below detection limit (bdl) -13.6 μg L-1 in dry season as quantified by enzyme-linked immunosorbent assay. Meanwhile, independent t test analysis indicated that there was significant difference in concentration at p ≤ 0.05 between the seasons with respect to sediment and water samples. This demonstrated that climate-induced variations had considerable influence on contamination. While diazinon and carbofuran were equally applied intensively, their levels were below the detection limit in the all the samples analyzed. ELISA results were validated by the capillary-HPLC photodiode-array detector instrument analysis, and statistical comparison showed no significant difference between them. It was evident that chlorpyrifos residues determination in water and sediment by ELISA can be a useful strategy in environmental management and monitoring program, and a complimentary analytical tool to high performance liquid chromatography. Levels of chlorpyrifos detected in sediment and water were found to exceed recommended criteria for protection of aquatic life and preservation of water quality and may be hazardous if not regularly monitored. © 2012 Springer Science+Business Media B.V.
Climate; ELISA; Enzyme linked immunosorbent assay; Mean concentrations; Pesticides residues; Photodiode array detectors; Significant differences; Statistical comparisons; Catchments; Contamination; Drought; Environmental management; High performance liquid chromatography; Lakes; Pesticides; Rain; Sediments; Water; Water quality; Sedimentology; carbofuran; chlorpyrifos; dimpylate; pesticide residue; rain; chlorpyrifos; pesticide residue; agricultural emission; chlorpyrifos; climate effect; environmental management; enzyme activity; horticulture; lacustrine deposit; lake pollution; lake water; liquid chromatography; pesticide; pollution monitoring; quantitative analysis; sediment pollution; spatial distribution; strategic approach; article; catchment; climate; controlled study; enzyme linked immunosorbent assay; high performance liquid chromatography; intermethod comparison; Kenya; lake; limit of detection; precipitation; seasonal variation; sediment; water pollution; chemistry; climate change; environmental monitoring; lake; risk assessment; water pollutant; Kenya; Lake Naivasha; Rift Valley; Chlorpyrifos; Climate Change; Environmental Monitoring; Enzyme-Linked Immunosorbent Assay; Geologic Sediments; Kenya; Lakes; Pesticide Residues; Risk Assessment; Water Pollutants, Chemical