Qualitative and quantitative analysis of pesticide residues in flower farms soils around lake Naivasha basin, Kenya

Abstract

Lake Naivasha basin is the highest producer of flower in Kenya. The area also has higher pesticide application to increase quality and quantity of flower mainly for export. Even though these chemicals may be effective in achieving this goal, the incidence of xenobiotic pesticide residues on the environment, some of which leach into Lake Naivasha, have been of serious con­cerns. The objective of this study was to assess the level of flower farm soils contamination by organochloride and organophosphate pesticides in major flower farms around Lake Naivasha basin. One hundred soil samples were collected from randomly selected greenhouses within main flower farms. The analytical methods included solvent extraction of pesticide residues and their subsequent identification and quan­tification using High Pressure Liquid Chromatography (HPLC). Ten different organochloride and ten different organophosphate pesticides were analyzed. The analytical results showed that aldrin, dieldrin and endosulfan, endrin, lindane, dimethoate, malathion, parathion, chlorpyrifos and pirimofos residues were detected in various con­centrations. Methyl parathion had the highest mean concentrations of 87.84 ± 3.86μg/g of soil samples while Endrin, lindane, chlorpyrifos and pirimofos were not detected in some greenhouses. Routine monitoring of pesticide residues in these study areas is necessary for the prevention, control and reduction of environmental pollution and health risks.