Metal accumulation in two crab species from the Woji Creek (Nigeria) and human health risk assessment due to crab consumption: Callinectes sapidus and Cardisoma armatum

This study evaluates the concentrations of Cd, Cr, Pb, Ni, As and Cu in water, sediment and tissues (gill, muscle, hepatopancreas) of two crab species (Callinectes sapidus and Cardisoma armatum) collected from the Woji Creek in Niger Delta, Nigeria. As well as the health risk of consuming the crabs was determined. Mean values of metals in surface water revealed concentrations (mg/L) of a trend of Pb (3.252) > Cu (2.328) > Cr (1.590) > Cd (0.146) > Ni (0.109) and in sediments, the trend was in the order Pb (140.930) > Ni (37.481) > Cr (29.984) > Cu (21.001) > Cd (8.910). Hepatopancreas of the crabs accumulated higher concentrations of Cd and Pb; with mean concentrations of Cd and Pb of 0.110 ± 0.008 mg/kg and 1.364 ± 0.060 mg/kg in Callinectes amnicola, and 0.112 ± 0.008 mg/kg and 0.735 ± 0.026 mg/kg in Cardisoma armatum respectively. In the tissues of the three crab species, Pb and Cr were highest; while As was very low in the crab species. The HI was below 1 for males and females (adults and children) which indicates no risk to health from consumption of the edible crab species. Although the risk due to the consumption of these is low, they could be a dietary source of chronic doses of metals to humans.