LEVELS OF ENDOSULFAN AND O,P’-DICHLORODIPHENYLTRICHLOROETHANE RESIDUES IN CLARIAS GARIEPINUS, WATER AND SEDIMENT FROM SOME CREEKS IN AKWA IBOM STATE, NIGERIA
Anietie Peter Effiong, Emmanuel Iweh Etim, Stella Folajole Usifoh and *Cyril Odianose Usifoh
Fish samples (Clarias gariepinus) from five fishery sites in Akwa Ibom State, Nigeria were studied. Extraction of the pesticides from the fish was carried out followed by purification in a column conditioned with n-hexane and dichloromethane as mobile phase. The extract was then analyzed with GC-MS. The result displayed that the highest mean residual concentration of endosulfan occurred in fresh fish obtained from Ifiayong Esuk (0.021± 0.071 x 10-2 mg/kg), smoked-dried fish from Ayadehe (0.016 ± 0.000 x 10-2 mg/kg), water from Ifiayong Esuk (0.530± 0.000 x 10-2 mg/kg) and sediment from Issiet Creek (0.922 ± 0.000 x 10-2 mg/kg). All the values were statistically significant (p-value <0.05) compared to the reference value. The mean residual concentration of o,p’-dichlorodiphenyltrichloroethane (o,p’-DDT) detected in sediment from Ibeno Creek was 0.005± 0.007 x 10-2 mg/kg. The health risk estimation (hazard quotient) of endosulfan residues in fresh and smoked-dried fish samples were lower than the US Environmental Protection Agency’s chronic reference concentration of 0.006 mg/kg day and the toxicity threshold limit of 1.00. From the results of this work, the aquatic and terrestrial environments under study contained endosulfan and o,p’-DDT and these chemicals may induce lethal or sublethal effects on Clarias gariepinus.
Keywords: Pesticides, Toxicity, Pollution, Catfish, Water, Sediment, GC-MS.
[Full Text Article]