Bio-Monitoring of Atmospheric Heavy Metals (Co, Cr, Cu, Fe, Ni, Mn, Pb, Zn) Using Leaves of Five Different Tree Plants in Kazaure Metropolis

Tree plants species are essential biotic components of ecosystems. These plants are often grown in urban areas to serve a number of purposes such as beautification, wind break, shades etc. the urban centres no doubt are greeted with numerous anthropogenic activities which introduce lots of contaminants in the name of heavy metals, HMs into the clean environment. Leaves of five tree plant species (Cassia acutifolia, Casuarina equisetifolia, Dalbergia nigra Mangifera indica and Terminalia catappa) were used to monitor the levels of HMs in Kazaure Local Government Area, LGA. Concentrations of Co, Cr, Cu, Fe, Ni, Mn, Pb, Zn were determined by Atomic Absorption Spectrophotomer, AAS. The leaves samples bioaccumulated all the assayed metals in the environs of Kazaure. The results revealed the following range; Leave of C. acutifolia (0.40 – 92.52 mg/Kg), C. equisetifolia (0.50 – 199.92 mg/Kg), D. nigra (0.80 – 100.02 mg/Kg) M. indica (0.60 – 75.03 mg/Kg) and T. catappa (0.73 – 185.02 mg/Kg). The leaves of C. equisetifolia and T. catappa accumulated the highest level of total metals. Though none of the studied plant species is a hyperaccumulator, they are good biomonitor of toxic metals in the locality of Kazaure. Concentration of Ni is only above the permissible limit in C. equisetifolia and T. catappa. The level of Pb is above the permissible limit in all the plant species suggesting the contamination of the studied area. Cr level is also higher in C. equisetifolia and D. nigra. The levels of other HMs reported in this study are lower than the permissible limit. The findings here-in may be utilized for future surveillance as preliminary reference values for amount of HMs in metropolitan settings.