Accumulation of Some Heavy Metals in Oreochromis niloticus from the Nile in Egypt: Potential Hazards to Fish and Consumers

Abstract

Exposure to heavy metals is an important environmental problem resulting from anthropogenic activities. The aim of this study was the evaluation of some heavy metals as cadmium (Cd), lead (Pb), chromium (Cr) and aluminum (Al), in muscle of fresh water fish Oreochromis niloticus from ten provinces all over Egypt to assess its possible hazards on fish and consumers. The analyzed metals could be detected in all examined samples and their order was Pb > Cr > Cd > Al. A positive correlation between Al concentration and the fish length was observed. The concentrations of Pb, Cd and Cr in fish samples were several times higher than their concentration in water and the bioaccumulation Factor (BAF) ranged from 8.22 - 122.6. The estimated weekly intake of Cd, Pb and Cr for a 70 kg person consuming fish in Egypt (7.94, 15.84 and 9.8 µg) is well below the Provisional Permissible Tolerable Weekly Intake (PTWI) recommended by FAO/WHO. Although heavy metal levels in Egypt exceed the maximum permissible limits recommended by Egypt and WHO in some fish samples, the consumption of Nile O. niloticus from Egypt is safe on human health.