Heavy Metal Contamination in Selected Fishes from Ojo, Lagos Nigeria

Abstract

This study was embarked on to investigate the status of heavy metal contaminants in tissues of five fish species from Ojo, Lagos, Nigeria. Adult Sarotherodon melanotheron, Chrysichthys nigrodigitatus, Liza Falcipinnis, Eleotris vittata and Psettia sebae were obtained from fishermen in jetty and a local market in Ojo, Lagos, Nigeria. The cadmium (Cd), lead (Pb), zinc (Zn), copper (Cu), chromium (Cr) and iron (Fe) presence in the tissues of S. melanotheron, C. nigrodigitatus, L. falcipinnis, E. vittata and P. sebae were examined and the trace metals levels were quantified plying Atomic Absorption Spectrophotometer (AAS). The heavy metal levels found in the tissues were compared to the limits permitted of some global guidelines. The concentration of cadmium in the fish species samples span from 0.40-0.85 mg/kg. The Pb concentration in the fish samples range from 1.25-2.50 mg/kg. The Fe concentration in the fish species range from 20.16-42.50 mg/kg. The Cu concentration in the fish species samples range from 2.17-4.77 mg/kg. The Zn concentration in the fish samples range from 176.02-262.60 mg/kg. The Zn level in every fish specimen was higher than the allowable limit, while the Cu level in all the fish samples were below the allowable limit. Chromium was not found in the fish samples. All the five species of fish showed the potential to accumulate high level of heavy metals (Cd, Zn and Pb) in their tissues which could be unsafe for human consumption in the long term.