Bioaccumulation of Carcinogenic and Non-Carcinogenic Metals in Tympanotonus Fuscatus from Nigerian Mangroves: Health Risk Assessment.

Abstract:

Metals and metalloids contamination in aquatic environments poses significant ecological and human health risks, particularly in mangrove ecosystems exposed to industrial and domestic pollution. This study investigates the bioaccumulation of iron (Fe), zinc (Zn), lead (Pb), cadmium (Cd), copper (Cu), and arsenic (As) in Tympanotonus fuscatus var. fuscatus from the soft-bottom mangrove swamps of Lower Ibaka Creek, Rivers State, Nigeria. Samples were collected bi-monthly from three Sites between January and June 2023. A total of 270 shellfish samples were analyzed using Atomic Absorption Spectrophotometry (AAS) after nitric acid digestion following APHA methods. Quality control measures included reagent blanks, certified reference materials, and calibration standards. Results indicate Fe and Zn were the most abundant metals, while Pb, Cd, Cu, and As were detected at lower concentrations. Pb and Cd exceeded permissible limits in some locations. The estimated daily intake (EDI) and hazard quotient (HQ) values were below threshold limits, suggesting no immediate non-carcinogenic risks, although higher HQ values for children indicate increased susceptibility. Cancer risk (CR) values for Pb and As remained within acceptable limits. ANOVA and Duncan’s Multiple Range Test (p<0.05) revealed significant spatial variations in metal accumulation. The findings highlight potential ecological threats and the need for pollution control strategies. Continuous environmental monitoring and further research on bioaccumulation pathways are recommended to safeguard aquatic resources and human health in the region.