Assessing the Trace Metal Content of Groundwater in the Bakassi Peninsular, Onshore Rio del Rey, Akwa-Mundemba, Cameroun

Abstract

The present work assesses the trace metal content in groundwater from Akwa-Mundemba, Bakassi Peninsular in Cameroon. 12 groundwater samples were analyzed using Inductively Coupled Plasma Mass Spectroscopy ICP-MS. Field measurement of physicochemical parameters was determined. R-mode statistical analysis; Pearson’s Correlation Analysis (PCA) together with Hierarchical Cluster Analysis (HCA) between the trace metals and the physico-chemical parameters was carried out. Ten indices were determined: Four trace metal hazard indices; the average daily dose ADD (2.5E—07 to 0.2)) carcinogenic risks CR (2.1E—06 to 9.9E—04) and the non-carcinogenic risk hazard quotient HQ (5.7E—04 to 0.78) which yields the hazard indices HI (0.1 - 0.78), and six trace metal pollution indices; Degree of contamination DC (—13.53 to —11.02), Enrichment factor EF (0.26 - 35.47), Ecological risk factor Er (—29.92 - 7.04), Potential ecological risk index RI (-61.2-43.43), Pollution load index PLI (—0.01 - 0.04) and Geo-accumulation index Igeo (4.8E-09-3.0). From health risk indices and pollution evaluation indices on trace metals, the groundwater in Akwa-Mundemba area is safe for drinking. The enrichment factors show that the sources of the trace metals are from geogenic and anthropogenic processes. Arsenic, Lead and Vanadium are enriched although they are below the hazard risk values; this shows they have pollution potential that could be attributed to weathering and agricultural wastes. The severity of metal toxicity is governed by several factors, such as dose, nutrition, age, and even life style. Therefore, these low trends might not guarantee the complete absence of human health risks. Generally, from risk assessment on trace metals using risk indices in the analyzed groundwater samples might not cause any health risk. However, due to an increasing level of environmental pollution that might be imposed by increasing human activity in this area, groundwater sources might become a potential sink of contaminants; this is significant reason that makes constant monitoring, implementation and treatment of groundwater for drinking purposes necessary.