Assessment of Water Contamination by Heavy Metals and Radionuclides Near Industrial, Automobile, and Residential Areas in Gboko, Nigeria

Water contamination by heavy metals and radionuclides poses a major environmental and public health concern due to their toxicity, persistence, and bioaccumulation potential. This study aimed to assess the contamination levels of water sources near industrial, automobile, and residential areas in Gboko, Nigeria. Specifically, the concentrations of heavy metals such as lead (Pb), cadmium (Cd), chromium (Cr), iron (Fe), and zinc (Zn), as well as naturally occurring radionuclides including ²²⁶Ra, ²³²Th, and ⁴⁰K, were analysed in borehole, well, and stream water samples. Results showed that residential areas generally had metal concentrations below WHO permissible limits, while automotive and industrial areas recorded higher levels, especially for Pb, Cd, Cr, and Fe. Lead levels in industrial streams reached 0.04 mg/L, exceeding WHO standards, with potential long-term health risks such as neurological damage and kidney dysfunction. Radionuclide activity was highest at the industrial sites, with Total Annual Effective Dose (TAED) values ranging from 0.00146 to 0.00221 mSv/year, which, although within WHO safety limits, approached the Excess Lifetime Cancer Risk (ELCR) thresholds. The elevated contamination levels in industrial and automotive areas were attributed to emissions from vehicular activities, industrial discharges, and surface runoff carrying pollutants into water bodies. Overall, while zinc concentrations remained within safe limits across all sites, the presence of other heavy metals and increasing radionuclide activities in industrial areas indicate a growing pollution burden. The study concludes that periodic monitoring and implementation of pollution control measures are essential to mitigate the potential health hazards associated with contaminated water sources in Gboko, thereby ensuring the safety of residents who rely on these water supplies for domestic and drinking purposes.