Health risk assessment of heavy metals in sediment, shrimp (Parapenaeopsis atlantica), and periwinkles (Tympanotonus fuscatus) from Esuk Ibeno Beach, Akwa Ibom State, Nigeria

Beaches play an important role in the survival of the world. They serve the purpose of water supply for domestic, industrial, agricultural, and power generation. Beaches are also used for the disposal of industrial and sewage waste, putting rivers under tremendous pressure due to human activities. This research assesses heavy metal contamination in sediments, shrimps (Parapenaeopsis atlantica) and periwinkles (Tympanotonus fuscatus) from Esuk Ibeno Beach, Akwa Ibom State, Nigeria, to ascertain their potential human health risks to consumers. Shrimp samples and periwinkle samples (at low tide) were obtained with the help of local fishermen from Esuk Ibeno beach. Sediment samples were collected at the same location as the periwinkles. Concentrations of chromium (Cr), iron (Fe), nickel (Ni), copper (Cu), lead (Pb), and cadmium (Cd) were analyzed using atomic absorption spectrometry. The sediments indicated heavy metal concentrations of Cr (0.24-0.32 mg/kg), Fe (25.0-41.4 mg/kg), Ni (0.27-0.38 mg/kg), Cu (0.05-0.11 mg/kg) Pb (0.03-0.09 mg/kg), and Cd (0.01-0.02 mg/kg), all below the quality standards of marine sediments. In the biota, Fe concentrations in shrimps (8.80±0.25 mg/kg) and periwinkles (0.90±0.03 mg/kg) exceeded the FAO/WHO limit of 0.5 mg/kg, while Cr, Ni, Cu, Pb and Cd were within the permissible limits. Biomagnification was apparent for Cr (1.00) and Cd (2.00) in the periwinkles. Dietary exposure assessments showed ingestion rates for adults and children, with the Expdiet values for Cr, Fe, Ni, Cu, Pb and Cd being lower than the oral reference dose (RfD). The target hazard quotient (THQ) values were less than 1 for all metals, indicating that there were no significant health risks. The cumulative hazard indices for shrimps (1.56×10-2 in adults; 1.61×10-2 in children) and periwinkles (1.11×10-2 in adults; 1.15×10-3 in children) suggest potential long-term risks of bioaccumulation. Incremental lifetime cancer risk (ILCR) for all investigated metals were 1.0×10-6 and 1.0×10-4. This indicates that the consumption of Parapenaeopsis atlantica and Tympanostus fuscatus from the Esuk Ibeno beach was within the acceptable range. This study indicates a great impact of anthropogenic activities on Esuk Ibeno Beach and calls for sustainable industrial waste management to prevent environmental and public health hazards.