Assessment of heavy metal content in groundwaters of Ikpe Community, Akwa Ibom State, Niger Delta, Nigeria

Abstract

Accumulation of heavy metals in groundwater system could portend adverse health consequences to users. Heavy metal content of five randomly selected hand dug wells in Ikpe community, Akwa Ibom State, Nigeria was assessed between April and November 2022. The water was evaluated using standard methods and water quality indices to determine its suitability for human consumption. Eight heavy metals were evaluated using Heavy metal Pollution Index (HPI) and Comprehensive Pollution Index (CPI). The results were compared with the National drinking water standard. Results showed that chromium ranged from 0.001 to 0.20 mg/L, cadmium (0.001 - 0.008 mg/L), nickel (0.01- 0.08 mg/L), manganese (0.001- 0.6 mg/L), zinc (0.36 -1.90 mg/L), iron (0.1 - 0.8 mg/L), lead (0.001 - 0.02 mg/L) and arsenic (0.00 - 0.004 mg/L). HPI and CPI ranged between 44.62-126.30 and 0.18-1.33, respectively. Concentrations of these heavy metals exceeded acceptable limits, except lead and arsenic. The concentration of the metals from wells 2, 4 and 5 were generally higher and/or had values that exceeded acceptable limits. This could be attributed with geogenic and anthropogenic influences as well as the general conditions of the wells and their environment. The water quality indices (HPI and CPI) showed varying levels of heavy metal pollution in line with the heavy metal concentrations. Consequently, it can be concluded that water from wells 2, 4 and 5 is not suitable for human consumption, and it can be used for other purposes.