Health implications of the oral and dermal exposure to heavy metals in borehole water from a poorly remediated Ikot Ada Udo community, Akwa Ibom State, South-South Nigeria

Abstract

The health implications due to the exposure to heavy metals from boreholes were studied. Water samples (n = 24) were analyzed for lead (Pb), cadmium (Cd), nickel (Ni), chromium (Cr), and iron (Fe) using an inductively coupled plasma optical emission spectrometer (ICP OES, Varians-720-ES). The mean metals in boreholes were 0.085 ± 0.070 mg/L (Pb), 0.437 ± 0.142 (Cd), 0.034 ± 0.026 (Ni), 0.056 ± 0.028 (Cr), and 0.351 ± 0.066 mg/L (Fe). The mean Pb, Cd, and Cr were above the WHO limits for drinking water. Children were more vulnerable to heavy metals. The oral exposure of adults to Cd (1.37 × 10−2 mg/kg/day), children to Pb (1.02 × 10−2 mg/kg/day) and Cr (6.72 × 10−3 mg/kg/day), the dermal exposure of adults (6.51 × 10−5 mg/kg/day) and children (1.92 × 10−4 mg/kg/day) to Cd , the hazard quotient (HQ) from the oral exposure of adults to Cd (13.70 × 100), children to Pb (2.91 × 100) and Cr (2.24 × 100), the HQ from dermal exposure of adults (2.60 × 100) and children (7.68 × 100) to Cd, and the hazard index (HI) from the oral and dermal exposure of adults and children to heavy metals indicates impending health challenges. The carcinogenic risk (CR) of Pb (3.14 × 10−1), Ni (6.23 × 10−4), and Cr (3.53 × 10−3) in adults and those of Pb (1.20 × 100), Ni (2.40 × 10−3), and Cr (1.34 × 10−2) in children signifies the potential of having cancer within a 70-year lifespan. The potential health hazards to indigenes indicate the necessity for proper clean-up.