Contamination of roadside soil and grass with heavy metals

The concentrations of heavy metals were determined in roadside soil and grass from different locations in Ibadan metropolis and two highways. The levels found (in μg g −1) were: Cr - 20.6-104; Mn - 86.2-355; Fe - 1737-4455; Ni - 10.9-115; Cu - 8.94-80.5; Zn - 43.5-213; Cd - 0.18-2.70; and Pb - 205-730. There was no significant difference (P < 0.10) between the mean concentrations of these metals in the high and low traffic density areas suggesting that sources other than the motorcar also influence the levels of these metals in roadside soil and grass.