Determination of Heavy Metals in Soil and Plants along Major Road in Hong Local Government Area, Adamawa State, Nigeria

Abstract

Heavy metal concentration in roadside soil and plants are increasingly becoming of health concern. This work determined the concentration of selected heavy metals (Cd, Pb, Zn, Cr, Fe, Mg, Mn, Co, Ni and Cu) in roadside soils and plants samples from selected sites (Plaifu, Shiwa, Fadama-rake and Damdrai) along major road in Hong. Soil samples were taken 10 m, 20 m and 30 m away from the edge of the road at the  depth of 0-10 cm, 10-20 cm and 20-30 cm. Plant samples were randomly collected within the vicinity where the soil samples were taken and were analysed using Atomic Absorption Spectrophotometer. The result revealed the trend in soil heavy metal concentration was Fe > Mn > Mg > Pb > Zn > Ni > Co > Cu > Cr > Cd and for plant the trend was Fe > Mn > Mg > Zn > Pb > Ni > Cu > Cd > Co > Cr. The concentrations decreased with increasing distance away from the edge of the road as well as with depth at which the soil sample were taken. The transfer factor showed that the concentration of Zn, Mn, Cu and Mg were greater than 1, which shows that plant were enriched by Zn, Mn, Cu and Mg from the soil. Mg and Cd equal to 1 at Plaifu and Damdrai. Most of the values of TF at the study area super pass 0.5, which implies that generally, the ability of bioaccumulation of these heavy metals in examined plants were relatively high.