Assessment of heavy metal contamination in selected wells and boreholes in Amansea, Awka North, Anambra State, Nigeria

Abstract

This study assessed heavy metal contamination in selected wells and borehole water in Amansea, Awka North, Anambra State, focusing on the concentrations of Lead (Pb), Nickel (Ni), Cadmium (Cd), Mercury (Hg), Cobalt (Co), and Arsenic (As). The Agilent FS240AA Atomic Absorption Spectrophotometer method was used. Our findings reveal that well water contains higher concentrations of Pb  0.0467±0.0233) and Ni (6.143±1.0655) compared to borehole water (Pb: 0.0095±0.0062; Ni: 4.40316±1.1099), although no significant differences were observed (p > 0.05). Both water sources exceeded WHO/FAO acceptable limits for Pb (0.01) and Ni (0.02). Cadmium levels were also higher in well water (0.0267±0.0091) than in borehole water (0.0157±0.0072), with both exceeding safety standards (0.003). Mercury concentrations were slightly higher in borehole water (0.1198±0.0379) than in well water (0.1175±0.0561), but again, no
significant difference was noted (p > 0.05), with both sources surpassing acceptable limits. Cobalt levels were higher in borehole water (0.1543±0.1492) compared to well water (0.0133±0.0079), exceeding WHO/FAO limits only in borehole water. Lastly, Arsenic levels were higher in borehole water (0.0175±0.0054) than in well water (0.0155±0.0028), with both exceeding safety thresholds. These results underscore the urgent need for monitoring and remediation strategies to address heavy metal contamination in water sources, safeguarding public health in Amansea.