Monitoring the occurrence and distribution of selected organophosphates and carbamates pesticide residues in the ecosystem of Lake Naivasha, Kenya
Publication Date
2014-08-07Author
P. Otieno, P.O. Owuor, J.O. Lalah, G. Pfizer, K.-W. Schramm
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Show full item recordAbstract/ Overview
Although use of pesticides is critical in agricultural production, their residues
present a potential risk to non-target organisms and lower the quality of surface
water. In Kenya for instance, widespread use of pesticides in the catchment of
Lake Naivasha, has raised concern over the years due to possible pollution of the
lake through discharge of runoff from agricultural fields. In this study, sediment,
water, and fish samples were analyzed for selected pesticide residue
contamination. Chlorpyrifos-ethyl (CPF) was detected in the range of
2.6 24.9 ng/ml and 6.8 35.8 ng/g dry weight (dw) in water and sediment,
respectively. Meanwhile, diazinon was detected in the range of below detection
limit (bdl) to 33.3 ng/ml and bdl to 9.3 ng/g dw in water and sediment,
respectively. CPF was detected in fish tissues (Niloticus leucosticus) in the range
of bdl to 8.9 ng/g dw with diazinon and carbofuran not detected in any fish sample.
A significant difference was observed between different seasons with wet season
recording higher levels. Concentrations detected varied seasonally and on average
exceeded the maximum criterion set by European Union. Therefore, data
generated in this study are useful in environmental risk assessment and as a
baseline in formulation of mitigation measures to protect the lake from pesticides
residues pollution
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- Department of Chemistry [326]