Pesticide residues in the water and Fish (lagoon tilapia) samples from lagoons in Ghana

Abstract

This study was to ascertain the presence and subsequent amount of four organochlorine pesticides: dichlorodiphenyl dichloroethylene (2,4'-DDE), 4,4'-dichlorodiphenyldichloroethane (4,4'-DDD), p,p'-dichloro- diphenyltrichloroethane [p,p'-DDT (r) (i) (f)] and Propiconazol (f); and four organophosphorous pesticides: Fen i troth ion (i), Chlorpyrifos (i), Dichlorvos (a) (i) and Diazinon (a) (i) in Chemu lagoon (Tema), Korle lagoon (Accra), Fosu lagoon (Cape Coast) and the Etsii lagoon (Abandzi). Liquidrliquid and liquid-solid extraction technique was employed to extract pesticide residues in water and fish samples, respectively, using 1:1 (v/v) ethyl acetate/ dichloromethane mixture before being analyzed by gas chromatography. The highest level of pesticide contaminations was recorded in the Chemu lagoon as compared to the Korle lagoon and Fosu lagoon, with the Etsii lagoon showing the least contamination. The total average pesticide residues in water samples from the four lagoons: Chemu, Korle, Fosu and Etsii are 2.6384 mg/L, 0.4992 mg/L, 0.3045 mg/L and 1.3629 mg/L, respectively The total average pesticide residues obtained in fish samples (Sarotherodon melaanothern) from the Fosu and Etsii lagoons are 0.0155 mg/kg and 0.0088 mg/kg, respectively. This shows some level of exposure of pesticide which would be harmful to human. © 2009 Chemical Society of Ethiopia.