Use of Leptadenia Hastata as a Biomonitor of Heavy Metal Pollution in Dutse

Abstract

The leaves of Leptadenia hastata were tested as a possible biomonitor of heavy metal pollution in Dutse, Jigawa State, Nigeria. Concentrations of Cd, Cu, Pb and Zn were determined in unwashed and washed leaves and the associated soils collected from different sampling sites. The Cd, Cu, Pb and Zn concentrations ranged from 7.54-15.08, 8.33-12.50, 0.36-0.47 and 15.67-61.11 mg/kg in the unwashed leaves respectively, while in the washed leaves the concentration ranged from 5.01-8.12, 5.45-6.50, 0.19-0.25 and 14.67-30.00 mg/kg for Cd, Cu, Pb and Zn respectively. In the soil supporting the plant the values of Cd, Cu, Pb and Zn ranged from 2.22-6.75, 17.19-34.90, 0.74-1.07 and 34.44-82.22 mg/kg respectively. The results of the analysis showed that the concentrations of the heavy metals in the unwashed leaves were significantly higher than the washed leaves. The levels of Cu and Pb were found to be within the normal range set by European Union Standards (2006) of 40.00, and 0.30mg/kg respectively, while Cd levels were found to be above the normal range of 0.20mg.kg, set by European Union Standards (2006) as reported by Adah, C.A. (2013). This indicates contamination of the plant with Cd. The result also showed that Leptadenia hastata can be used as a biomonitor of heavy metal pollution.