Assessment of Some Heavy Metals Concentration and pH in Some Seafoods Found in Borokiri, Trans-Amadi, Eagle Island and Iwofe Swamps, Rivers State Nigeria

Aim: To assess the levels of heavy metals (cadmium, lead, chromium, copper), and pH in periwinkles, whelks, oysters, sediment, and water found in some swamps in Rivers State.

Study Design: Analytical Cross-sectional study.

Place and Duration of Study: Borokiri, Trans-Amadi, Eagle Island and Iwofe swamps, Rivers State Nigeria, between June and December 2022.

Methodology: Samples were collected from four different swamps in Rivers State: Iwofe, Eagle-Island, Trans-Amadi, and Borokiri swamps. Eagle-Island and Iwofe swamps are in Obio/Apkor LGA, while Trans-Amadi and Borokiri swamps are in Port Harcourt LGA. The solid samples were ground to powdered form to attain homogenous particles. Each sample was weighed, recorded and the concentrations of metals in the samples were determined. Five hundred (500) milligrams each of the ground samples were weighed and put into a crucible, 20 ml aqua regia (comprising 15 ml HCI and 5 ml HNO3) was added to digest the sample. Heavy metals in the digested samples were analyzed using GBC XplorAA Atomic absorption spectrophotometer (AAS). Where the concentrations were calculated using Beer-Lambert’s law. The statistical analysis was done using GraphPad Prism version 8.0.2 of Apple Macintosh HD Big Sur (version 11.0). Descriptive statistical tools such as mean & standard deviation (SD) were used. ANOVA was used to compare means of more than two groups for inferential evaluation, with Tukey’s multiple comparison test to check for mean difference between multiple groups. The probability (p) value less than 0.05 (P<0.05) was used and considered statistically significant.

Results: The results showed that the mean concentrations of cadmium, copper, and lead (0.001 ± 0.0001mg/l, 0.16 ± 0.07mg/l, and 0.01±0.003 mg/l respectively) were below the standard limit set by the World Health Organization (WHO), while chromium exceeded this limit, and the pH was also within acceptable range. From the results observed in the sediments and the tissue samples, the level of cadmium was below the standard limit set by WHO. However, chromium, copper, and lead had concentrations that were above the WHO recommended limit

Conclusion: Campaigns need to be launched to educate the public about the risks to health posed by improper disposing of household and municipal waste, industrial effluents, and pipelines, as well as the toxicity of heavy metals.