Pollution Assessment of Heavy Metals in Water and Sediment from Mpape River in FCT, Abuja, Nigeria

Levels of heavy metals (Cr, Mn, Cu, Fe, Zn, Cd, Ni, Pb) in water and sediment from Mpape River in FCT, Abuja were assessed. The study was carried out between 2015 and 2017. Water and Sediment samples were collected from five sites during dry and rainy seasons. Metal levels were quantified using AAS. Metal levels in water were generally below detectable limits, except for concentrations of Fe (0.30±0.20 mg/L) and Pb(0.22±0.30 mg/L) that were higher in dry and rainy seasons respectively. Pb level was above while Fe level was within permissible limits set by FAO/WHO. Concentrations of Mn (8.27±0.42 mg/Kg), Cu (0.57±0.09 mg/Kg), Zn (1.84±0.13 mg/Kg), Ni (0.16±0.06 mg/kg), Pb (2.63±0.19 mg/Kg) in sediment were significantly higher (P ≤ 0.05) during rainy season while Cr (1.77±0.22 mg/Kg), Cd (0.05±0.24 mg/Kg) and Fe (24.80±0.38 mg/Kg) were higher in dry season. Concentrations of Cu, Zn, Ni, Pb and Cd were lower than the permissible limits set by WHO and USEPA except for Cr, Mn and Fe that were above the limits. Metal Pollution Index assessment of heavy metals in sediment samples showed that rainy season recorded the highest value at site S3 (50.24). Correlation analysis showed that the relationships for Zn/Mn (0.941), Fe/Cu (0.853) and Pb/Cr (0.803) were strong and positive while Pb/Cd (- 0.781) was negative in dry season. However, strong positive; Ni/Cu (0.884), Zn/Mn (0.938) and Fe/Mn (0.952) correlations were recorded in rainy season. The strong positive correlation indicates that they have commonsource of pollution.