Heavy metals are metal with relative high density known to cause adverse effects on humans health through the food chain. Edible parts of different shellfish species Crab (Cardisoma crassum), Prawn (Macrobrachium rosenbergii), Crayfish (Decapoda reptania) and Shrimp (Penaeus notalis) were analyzed using atomic absorption spectrophotometer (AAS) for various concentrations of Pb, Cr, Ni and Hg. Concentrations of Pb and Cr in all shellfish species were above the Food and Agriculture Organization/World Health Organization permissible limit, while Ni and Hg were below detection limit. The heavy metal concentration in shellfish arranged in increasing order were Cardisoma crassum > Macrobrachium rosenbergii > Decapoda reptania > Penaeus notalis. The dangers to human health of eating shellfish from the Santa Barbara River in Nembe Bayelsa State were assessed. With the exception of Ni and Hg, the target hazard quotient (THQ) showed significant concern for ingestion of these shellfish. The hazard index (HI) suggests a high risk of human carcinogenesis. According to the life cancer risk (LCR) and total life cancer risk (TLCR) values, Pb and Cr levelswere notably high in youngsters. In conclusion, the very high quantity of these metals may be hazardous to shellfish directly or indirectly to people who regularly eat contaminated seafood. The consumption of fish from the Santa Barbara River in the Niger Delta may be hazardous to human health.

This study investigated the level heavy metal and health risk associated with marine sediment impacted with oil spill from Santa Barbara River, Nembe. Chemical analysis assessments of the marine sediments were investigated for different heavy metals Lead (Pb), Chromium (Cr), Nickel (Ni) and Mercury (Hg) respectively using flame atomic absorption spectrophotometer (AAS). The mean concentration of the marine sediment was found to be highest for Cr (24.03 ± 0.24), followed by Pb (1.53 ± 0.03) and Ni (3.93 ± 0.03) mg/kg respectively, while Hg was below detection limit. The result shows the heavy metals were below the recommended value stipulated by USEPA and RMENSR with exception of chromium which exceeded maximum permissible limit. This study recommended that there should be continuous monitoring of (Cr, Pb Ni and Hg) levels in sediments of Santa Barbara River to assess the risk of these metals in the river.