Health Risk Assessment of Heavy Metals: Cu, Cd, Pb, Ni and Hg, in Catfish Ariopsis felis in Southern Mexico

Metal pollution is a problem in many parts of the world. These metals can be harmful when they exceed the recommended limits. By analyzing metal concentrations in living organisms, it is possible to deduce the bioavailability and the level of environmental contamination for specific metals in an ecosystem. The aim of this study was to determine the heavy metals copper, cadmium, lead, nickel and mercury in edible tissues of fish, to establish the risk analysis for human health. There are currently no studies in this area indicating these factors.

The edible tissue samples were treated under the techniques of the official mexican standards (NOM-117-SSA1) and analyzed using atomic absorption spectroscopy (flame and graphite). The heavy metal concentrations were used to calculate the estimated daily intakes, target hazard quotients, hazard indices, and target cancer risks for children and adults.

The highest concentrations of copper (138.82 μg/g), cadmium (1.28 μg/g) and lead (3.20 μg/g) in the edible tissue samples exceeded the permissible limits considered in this study while nickel and mercury levels did not. The target hazard quotient indices for copper, cadmium and nickel in specific sites were higher than the United States Environmental Protection Agency (US-EPA) criteria (>1), while the values ​​for mercury and lead were below one. The hazard indices were higher than the US-EPA criteria (>1) in more than 50% of the sites analyzed. 

This study is an alert, indicating that inhabitants who consume the fish, particularly children, are at risk of cadmium, lead and nickel toxicity.