Bioaccumulation of some Heavy Metals and Total Hydrocarbon (THC) in the Tissues of Periwinkle (Tympanotonus Fuscatus Var Radula) in the Intertidal Regions of Qua Iboe River Basin, Ibeno, Akwa Ibom State, Nigeria

Abstract

The levels of some heavy metals and total hydrocarbon (THC) in the tissues of periwinkle ( Tympanotomus fuscatus ) from Qua Iboe River, Ibeno area in Akwa Ibom State were investigated. Three hundred samples of periwinkles were collected for a period of three months from two stations (Mkpanak-control and Itak Abasi-downstream) in the intertidal region of the River and were analyzed using Atomic Absorption Spectrophotometry for the determination of heavy metals and Soxhlet extraction gravimetric method was used in determination of total hydrocarbon. The mean levels of total hydrocarbon varied from 0.004-0.050 mg/g and the mean level of heavy metals also varied: Cadmium (Cd), 0.0430.53mg/g, Copper (Cu), 0.02-0.027mg/g, lead (Pb), 0.060-0.067mg/g, Mercury (Hg), 0.020-0.033mg/g, Nickel (Ni), 0.030.04mg/g in all the stations. The levels of heavy metals and total hydrocarbon during the study period in all stations across the months did not show significant difference (p> 0.05). This was attributed to the fact that, they were less industrial activities and close proximity of the stations to the major road where emissions from automobiles are abounded which is purely a residential area. These studies demonstrate that, the evidence of bioaccumulations of heavy metals and total hydrocarbons were below the recommended tolerable levels when compared to that of Federal Ministry of Environment. This implies that periwinkles from Qua Iboe River, Ibeno are safer now than before as a food source for consumers who delight in this delicacy. However, constant monitoring of water bodies receiving effluents is emphasized in order to forestall cumulative effects of pollutants which may lead to sub-lethal consequences in the aquatic fauna and clinical poisoning to man.