Determination of Organochlorine Pesticide (OCPs) in Shallow Observation Wells from El-Rahawy Contaminated Area, Egypt

Abstract

The contamination of organochlorine pesticides (OCPs) from the selected sites in El Rahawy area was investigated to estimate the current status of pollution in surface and groundwater. A study was conducted to determine the concentrations of OCPs in surface and groundwater samples along El Rahaway drain. Samples were collected from six different sites during the rainy and dry seasons. The samples were extracted by liquid-liquid extraction method then screened and determined qualitatively for 18 OCPs using GC/ECD (Gas chromatograph equipped with electron capture detector). There was a variation of pesticide residue levels with season. The commonly found OCP residues in the study area were α-HCH, γ-HCH, heptachlor, heptachlor epoxide, endosulfan I, endosulfan II, p,p'-DDE, p,p'-DDD and endrin. The overall results showed that surface water was more polluted with OCPs than groundwater, especially endosulfan I which was detected in the wide range concentration of 0.021 to 0.375 μg L^-1 and 0.083 to 0.823 μg L^-1 during dry and rainy seasons, respectively. There was a variation of pesticide residue levels with season. The OCPs levels in all water samples were generally exceeded Canadian water quality guidelines for the protection of agricultural water uses (CWQGs).