Health Risk Assessment of Heavy Metals in Groundwater Used for Domestic Purposes in Eket Metropolis, Akwa Ibom State, Nigeria

Abstract

Groundwater is the principal source of water for domestic purposes in many parts of Eket Metropolis, Akwa Ibom State, Nigeria, and its quality is therefore relevant to public health. This study presents a health risk assessment of heavy metals in groundwater used for domestic purposes in Eket Metropolis, Akwa Ibom State, Nigeria. Four borehole water samples were collected from four locations. The collected samples were analysed for Pb, Ni, Cr, Mn, Zn, Cu, Cd, and Co. Chronic daily intakes (CDIs) of metals through water ingestion and health risk indices (HRIs) were calculated. Pb, Ni, Cr, Mn, Zn, and Cu were detected at all four sampling locations. The concentrations of Pb, Ni, Cr, Mn, Zn, and Cu ranged from 0.003 - 0.013, 0.002 - 0.005, 0.005 - 0.011, 0.011 - 0.017, 0.031 - 0.036, and 0.010 - 0.019 mg/l, respectively, and their mean concentrations were within the WHO limits. Cd and Co were not detected. The HRIs for Pb in children at borehole locations B2 and B4 warrant concern because the calculated values exceeded unity (1). This indicates a potential health risk to children who use the groundwater for domestic purposes. These findings indicate that borehole water used for domestic purposes at some locations in Eket Metropolis, Akwa Ibom State, Nigeria, is contaminated with Pb and requires further monitoring. Continuous monitoring and additional studies are recommended to ascertain potential long-term effects. Further study is also recommended to assess the seasonal variability of toxic metals in the study area.