Heavy Metal Contamination in Fish (Callinectis amnicola) From an Estuarine Creek in the Niger Delta, Nigeria and Health Risk Evaluation

Heavy metal bioconcentration in crabs from an estuarine creek in the Niger Delta was examined using atomic absorption spectrophotometry. Health risk via human exposure to metal toxicity was evaluated. Mean metal levels (µg/g) were Cr 2.32 ± 0.71, Ni 2.76 ± 0.48, Cu 12.94 ± 3.53, Pb 5.67 ± 1.03, Ag 1.83 ± 0.71 and Cd 0.73 ± 0.14 with significant difference (p < 0.001) between periods. Ni, Pb and Cd had values above FAO/WHO recommended limits. Estimated daily intake values were below the reference oral doses and the target hazard quotient was <1 for each metal examined while hazard index for all metals was also <1. The target carcinogenic risk value for Ni was 3.4 × 10−3. Based on the evaluations, the study concluded that consumers of crabs from the study area had minimal/moderate metal toxicity exposures of no significant health concern but recommended continuous monitoring to detect anomalies.