Determination of the Heavy Metal Concentrations of Kundu River in Kwali Area Council, Federal Capital Territory, Abuja, Nigeria

Abstract

Illegal mining in rural communities of the Federal Capital Territory could have significant impact on aquatic ecosystems. Kundu River in Kwali Area Council is situated around rocky areas where intense mining activities are dominant.  Kundu community relies on this river for portable water and other domestic uses. Heavy metal contamination in surface waters poses serious risks to human health and aquatic ecosystems due to their toxicity and persistence. In this Study, the concentrations of selected heavy metals (Pb, Hg, Cd, As, Ni, Mn, Cu, Ca, Zn and Na) in Kundu River, Kwali Area Council, FCT, Nigeria. Water samples were collected from upstream, midstream, and downstream sites during the dry season and analyzed using Atomic Absorption Spectrometry (AAS) following acid digestion. Results showed that Pb (0.51 ± 0.03 mg/L), Hg (0.42 ± 0.02 mg/L), Cd (0.004 ± 0.001 mg/L), As (0.19 ± 0.00 mg/L), and Ni (0.12 ± 0.01 mg/L) exceeded the permissible limits set by WHO and Nigerian Standards for Drinking Water at one or more sites, while other metals such as Ca, Cu, Zn, Mn, and Na were within safe ranges. Spatial variations across sampling sites were not statistically significant (P>0.05), indicating a relatively uniform distribution of heavy metals along the river. The findings suggest that the river is impacted by anthropogenic activities, particularly mining, and that the water is not safe for direct human consumption. These results provide baseline data on heavy metal contamination in Kundu River and highlight the need for regular monitoring and effective pollution control measures to protect public health and maintain ecological integrity.