Evaluation of heavy metals in tissue of Tympanotonus fuscatus sold in some markets in port harcourt metropolis, Nigeria

Abstract

Tympanotonus fuscatus is found in mangrove swamps of the coastal region of the Niger Delta Nigeria. It is a source of protein, Hence it is used in the preparation of delicacies. This study evaluated the level of heavy metals in tissues of Tympanotonus fuscatus sold in some markets in Port Harcourt, Rivers state, Nigeria. Triplicate samples of Tympanotonus fuscatus was purchased from seven different markets within Port Harcourt metropolis. The samples were digested and analyzed using a Flame atomic absorption spectrometer. Results showed that the concentration of the heavy metals ranged from 0.76-1.56mg/kg (nickel), 22.36-29.28mg/kg (zinc), 185.07-921.49mg/kg (iron), 0.05-0.56mg/kg (lead), 80.96-102.62 mg/kg (cobalt) and 19.04-69.45 mg/kg (manganese). Moisture and organic matter contents ranged from 78.88-85.87% and 86.06-92.23% respectively. Analysis of variance showed that there is significant difference (P<0.05) in most of the locations for each of the parameters. The variation that exists could be due to differences in the pollution load of the aquatic habitats from which the samples were harvested. Based on permissible limit, the heavy metals concentration were within allowable limit for fish-food specified by Food and Agricultural Organization/World Health Organization, Median International Standard and European Union except for iron, manganese and copper. The high level of iron, manganese and copper suggests potential health effects.