Organochlorine and organophosphorous pesticide residues in the Ouémé River catchment in the Republic of Bénin

• Published in: Environment international Vol. 32; no. 5; pp. 616 - 623
• Main Authors: Pazou, Elisabeth Yehouenou A., Boko, Michel, van Gestel, Cornelis A.M., Ahissou, Hyacinthe, Lalèyè, Philippe, Akpona, Simon, van Hattum, Bert, Swart, Kees, van Straalen, Nico M.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Ltd 01.07.2006; Elsevier
• Subjects: Applied sciences; Benin; Continental surface waters; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Environmental Monitoring; Exact sciences and technology; Freshwater; Geologic Sediments - analysis; Geologic Sediments - chemistry; Hydrocarbons, Chlorinated - analysis; Hydrocarbons, Chlorinated - chemistry; Natural water pollution; Organochlorine; Organophosphorous pesticide; Organophosphorus Compounds - analysis; Organophosphorus Compounds - chemistry; Ouémé River; Pesticides - analysis; Pesticides - chemistry; Pollution; Pollution sources. Measurement results; Pollution, environment geology; Rivers - chemistry; Soil and sediments pollution; Water Pollutants, Chemical; Water treatment and pollution; Benin; Benin, Oueme R; Ouémé River; Organophosphorous pesticide; Organochlorine; Pesticides; Sediments; Spatial variation; Organochlorine compounds; Watershed; Surface water; Water quality; Stream; Organophosphorus compounds; Water pollution; Concentration distribution
• ISSN: 0160-4120; 1873-6750
• DOI: 10.1016/j.envint.2006.01.007

The Ouémé River is one of the most important rivers in the Republic of Bénin. It is 510 km long and its catchment drains 75% of the country. In this study, organochlorine and organophosphorous pesticide residues were measured in more than 35 sediment samples collected on nine locations along the Ouémé River from upstream to downstream. Except for one location, Tanéka-Koko, all areas were contaminated by more than 20 pesticides. Organochlorine pesticides identified in sediment samples included pp′-DDE, op′-DDD, pp′- DDD, op′-DDT, pp′-DDT, α-endosulfan, β-endosulfan, endosulfan sulphate, α-HCH, β-HCH, lindane, aldrin, dieldrin, endrin, telodrin, isodrin, cis- and trans-heptachlorepoxide, hexachlorbutadiene, hexachlorobenzene and octachlorostyrene. The organophosphorous pesticide chlorpyrifos, used in a new formulation to protect cotton, was also identified. In some areas, the concentrations of organochlorine pesticides in the sediment of the Ouémé River exceeded environmental quality standards and are reason for concern.