Organchlorine Insecticides and Polychlorinated Biphenyls Residues in Soil and Water Samples Collected From El-Gabal El-Akhdar, Libya

Saad A. S. A. , Elsayed H. M. Tayeb, Laila A. Mohamed and S. M. I. Hassan

Organochlorine insecticides (OCIs) such as HCH (a, β and γ Hexachlorocyclohexane), DDT (dichloro-diphenyl-trichloroethane) and its metabolites, aldrin, dieldrin and endrin  were determined in soil and groundwater samples collected from different locations at El-Gabal (AlJabal) El-Akhdar, Libya during summer  (August 2014)  and winter (January 2015) seasons. In addition, the residues of PCBs (polychlorinated biphenyls) species were inspected and determined. Generally, the calculated Σ DDT of the detected residues of DDT family members that have been detected in summer were higher (with a maximum of 10.110 μg/l) than those detected in soil samples of winter season (a maximum of 4.547 μg/l). The results demonstrated the absence of endrin in the majority of the study sites. The results indicated the presence of about seven species of PCBs in the soil samples at different sites (PCB28, PCB52, PCB101, PCB118, PCB135, PCB138 and PCB180). It was observed that OCI residues were detected in ground water samples during summer season at few sampling sites but they were almost absent during winter season. Water samples analysis in winter showed that there were only four sites that have been found to contain members of DDT isomers.. The residues of endrin were found in high levels in both water samples of summer (2.09 μg/l) and winter (1.25 μg/l) as compared with OCIs. Meanwhile, o,p DDE (0.9155 μg/l) and αHCH (1.3230 μg/l) were detected at high concentrations  during winter season in water samples. In winter, the results indicated that the highest concentration of PCB species was detected in water samples collected in summer and was found in Qandula location  (PCB 101= 7.239 μg/l), while the lowest mean of concentration was presented in the location of Al-Abraq where PCB 28 reached a concentration of 0.062 μg/l


Keywords: Organochlorine insecticides (OCIs), Polychlorinated biphenyls (PCBs), Residue analysis, El-Gabal El-Akhdar, Libya, irrigation underground water, soil