Impact of Trace Metal Bioaccumulation on Tympanotonus Fuscatus Consumed by Humans in Isaka Bundu Axis of the Bonny River, Rivers State, Nigeria

This paper assesses the influence of trace metal pollution on Tympanotonus fuscatus (periwinkle) in the Isaka-Bundu mangrove swamp, Rivers State, Nigeria. The study was carried out within three different stations, station 1, station 2 and station 3 located in PortHarcourt Local Government Area of Rivers State (Figure1). Isaka-Bundu mangrove swamp, which is located along the Upper reaches of Bonny Estuary has been subjected to pollution pressures The location is sited by companies such as Nigerian Ports Authority, OandO Oil and Gas, Conoil, Ibeto cement factory, dredging companies, etc. industrial and domestic wastes from the companies mentioned above, get settled in the swamp , adjoining creeks, and the densely populated coastal settlements on the banks. The samples were also analysed for Cr, Cd, Ni, and Zn concentrations with UNICAM Solaar 969 atomic absorption spectrometric machine (AAS-API-RP 45) The study was carried out at three sampling stations with a view to assessing spatial and temporal variations of Cadmium (Cd), Chromium (Cr), Zinc (Zn), and Nickel (Ni) concentrations as well as associated health risks. Spatial analysis showed significant variation with the highest Zn concentration recorded at Station 2 (12.668 mg/kg). Cadmium levels were relatively consistent at all the stations with a maximum of 0.05 mg/kg. It was in July that the trace metal concentrations were found to be the highest for all those analyzed, including Cd (0.077 mg/kg), Cr (0.018 mg/kg), Zn (11.795 mg/kg), and Ni (4.413 mg/kg). The results suggests a seasonal effect on the bioaccumulation of trace metals, mediated by environmental conditions like increased runoff. Estimated Daily Intake (EDI) values showed that children are more vulnerable than adults with the highest EDI values for Zn and Ni recorded at Station 2, which were 16.844 mg/kg and 4.449 mg/kg, respectively. The health risk assessment revealed that the Hazard Index (HI) exceeded the acceptable limit in children at Station 2 HI = 5.149, which indicates a potential chronic health risk. In addition, cancer risk (CR) for Ni was found to exceed the acceptable limit in both adults and children, pointing to serious concerns about long-term exposure. The study highlights the urgently continued need for effective control measures and ongoing monitoring to reduce the ecological and health risks associated with pollution by trace metals