Residues of cypermethrin and endosulfan in soils of Swat valley

Swat Valley was studied for two widely used pesticides; cypermethrin and endosulfan. A total of 63 soil samples were collected from 27 villages selected for this purpose. The collected soil samples were extracted with n-hexane, pesticides were separated, identified and quantified by a GC-ECD system. Endosulfan was 0.24 - 1.51 mg kg^-1 and 0.13 - 12.67 mg kg^-1 in rainfed and irrigated areas, respectively. The residual level of cypermethrin was comparatively high with a level of 0.14 to 27.62 mg kg^-1 and 0.05 to 73.75 mg kg^-1 in rainfed and irrigated areas, respectively. For assessing the possible causes of pesticide residues in soil, 360 farmers were interviewed. It was found that both, cypermethrin and endosulfan, apart from agriculture were also widely misused for fishing in the entire stretch of River Swat and its tributaries. River Swat is used for irrigation in Swat Valley and this wide misuse of pesticides can also contribute to pesticide residue in soil.