Heavy metal concentrations in water, sediment and periwinkle (Tympanotonus fuscastus) samples harvested from the Niger Delta region of Nigeria
Heavy metal pollution of terrestrial and aquatic environments in Niger-delta region of Nigeria is on the increase due to increased urbanization and crude oil exploration. Tympanotonus fuscastus are mud dwellers and could bioaccumulate heavy metals; therefore consumption of heavy metal contaminated sea foods like periwinkle may breed lots of health problems. Heavy metal concentration in water, sediment and Periwinkle samples from three locations (Itu-River, Abuloma River and Oron River) in the Niger Delta Region of Nigeria were evaluated using atomic absorption flame photometry. Result showed that cadmium (Cd) concentration was highest in water samples from Abuloma River (0.106 mg/l) while lead (Pb) concentration was highest (0.01mg/l) in the water samples from Itu River. Cd and Pb concentrations (0.127 and 0.08 mg/kg, respectively) in sediment samples were highest in Abuloma River. The concentration of Cd in T. fuscastus samples was 0.11 mg/kg in Abuloma River, while concentration was 0.27 mg/kg in Oron River. Copper (Cu) was generally low in the water samples; the highest concentration (0.011 mg/kg) was obtained in water samples from Oron River. Sediment concentration of Cu was high (0.088 mg/kg) in Itu River, while its concentration in the periwinkle samples was 0.54 mg/kg in Abuloma River. The results also showed that Cr, As and Hg were below detectable concentration in tissues, soil and water samples from Itu and Abuloma Rivers, while Hg concentration in Oron River sediment was 64.2 mg/kg.
Key words: Sea foods, heavy metals, pollution, environment, nutrition, bioaccumulation