Potential health risk of selected heavy metals levels; pH, temperature, and conductivity of groundwater: A case study of Omi-Adio Area, Ibadan, Nigeria

Abstract

The concentrations of selected heavy metals, along with pH, temperature, and conductivity, in hand-dug well water were assessed in Omi-Adio, a low-income suburb of Ibadan, Nigeria, where hand-dug wells serve as the primary water source. Twenty water samples were analyzed to assess the quality of drinking water. Heavy metals, including lead (Pb), cadmium (Cd), nickel (Ni), and chromium (Cr), were determined using atomic absorption spectrophotometry. Additionally, pH, temperature, and conductivity were also measured. Pb, Cd, Ni, and Cr concentrations ranged from not detected (ND)–0.77 mg/L, ND–0.03 mg/L, ND–0.13 mg/L, and ND–0.26 mg/L, respectively. Temperature ranged from 29.25–30.00°C, conductivity from 80– 932 μS/cm, and pH from 4.97–6.13. Most samples contained one or more metals at varying levels, exceeding World Health Organization guidelines in up to 75% (Pb), 20% (Cd), 20% (Ni), and 70% (Cr) of samples. The low pH values further indicated acidity below the World Health Organization's acceptable limits. Overall mean concentrations followed the decreasing order Pb > Cr > Ni > Cd. The calculated hazard index (HI) indicated potential non-carcinogenic health risks, with Pb > Cr > Cd > Ni. The findings reveal that the groundwater in Omi-Adio is unsuitable for direct consumption without treatment, as prolonged intake poses significant health hazards to humans and animals. Authorities should provide alternative, safe water sources, raise community health awareness, and implement monitoring programs to regularly evaluate groundwater quality and identify pollution sources, thereby ensuring access to safe and potable water.