PM = Polluted Maize, UM = Unpolluted Maize, PC = Polluted Cowpea, UC = Unpolluted Cowpea, PSV = Polluted Site Vegetation, USV = Unpolluted Site Vegetation, PSL = Polluted site Soil, USL = Unpolluted site Soil. †Means followed by a common letter within the same column do not differ significantly at 0.05 probability level.