Distribution and Human Health Risk Assessment of Heavy Metals in Tissues of Callinectes sapidus from Iko River, Akwa Ibom State, Nigeria

Abstract

This study investigates the accumulation of heavy metals in the tissues of Callinectes sapidus (blue crab) in the study area and evaluating the human health risk of their consumption. The tissues of concern were the gills, muscles and hepatopancreas in the male and female crab species, while the heavy metals assessed were Cd, Ni and Pb. Heavy metals levels in the tissues of Callinectes sapidus ranged as follow: Ni: hepatopancreas (182.97–313.53 mg/kg), gills (129.93–192.14mg/kg), muscles (93.09–165.84 mg/kg); Pb: hepatopancreas (22.86–39.65 mg/kg), gills (13.46–21.35 mg/kg), muscles (2.73 – 6.32 mg/kg); Cd: hepatopancreas (2.04 –9.03 mg/kg), gills (0.12–4.995 mg/kg), muscles (0.105–2.835 mg/kg), respectively. The highest metal concentrations were observed in the hepatopancreas tissue and in the female of the crab species. Furthermore, the metals’ levels were generally higher than the permissible level by FAO/WHO in seafood. To assess the heavy metals health risk to the inhabitants of the study area, the daily intake of metal (DIM) and total hazard Quotient (THQ) were estimated and were found to exceed the recommended values. The results reflect the risk of exposure for the period of life expectancy considered, and revealed that the inhabitants of the study area are highly exposed to the health risks associated with these metals.