Assessment of Heavy Metal Contamination in Surface and Groundwater and Associated Human Health Risks in Urban Communities (Coal Camp, Ogbete Enugu and Ngenevu Obed Camp Ogbete Enugu) of Enugu North Local Government Area, Enugu State, Nigeria

In Coal Camp, Ogbete Enugu and Ngenevu Obed camp Ogbete Enugu, located in the urban area of Enugu North
Local Government Area of Enugu State, Nigeria, residents rely heavily on local water sources, raising growing
concerns regarding potential contamination. To evaluate the exact scope of this issue, our research team examined
heavy metal levels (Pb, Cd, Cr, Hg, and Ni) across thirty field locations (6°25'N to 6°28'N, 7°28'E to 7°30'E),
sampling boreholes, unlined hand dug wells, and local surface streams (APHA, 2017). Uncontrolled municipal
waste, motor workshop runoff and agricultural chemicals have increasingly threatened these regional supplies.
Sampling was carried out in triplicates (N = 90) and analyzed via Atomic Absorption Spectrophotometry (AAS)
(Iwegbue et al., 2013). The laboratory findings were benchmarked against World Health Organization thresholds
(WHO, 2017). Detected metal concentrations spanned wide ranges: Pb (0.006 – 0.053 mg/L), Cd (0.001 – 0.012
mg/L), Cr (0.009 – 0.082 mg/L), Hg (<0.001 – 0.005 mg/L), and Ni (0.011 – 0.089 mg/L). Contamination intensity
decreased systematically in the order: Surface Water > Shallow Wells > Deep Boreholes. Risk modeling following
USEPA guidelines (USEPA, 2011) showed that Chronic Daily Intake and Hazard Quotient values for Lead and
Cadmium surpassed acceptable safety baselines (HQ > 1) near mechanic clusters, dumpsites, and quarry wash
zones, pointing to notable non-carcinogenic health hazards for local consumers (Tchounwou et al., 2012;
Jaishankar et al., 2014). These results demonstrate an immediate requirement for targeted public health monitoring
and targeted water purification in the affected areas.

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