Concentrations of Heavy Metals in Leaves along Roadsides in Port Harcourt, Rivers State, Nigeria

摘要

The concentrations of Cd, Cr, Cu, Ni and Pb in leaves collected along roadsides in Port Harcourt and environs were determined using GBC Avanta flame atomic absorption spectrophotometer Version 2.02. The metal concentrations in both seasons ranged from 0.001-19.530 Cr, 0.320-2.320 Ni, 0.118-1.150 Cd, 0.001-30.230 Pb and 0.386-3.850 ppm Cu. The difference between the dry and rainy seasons concentrations were significant (p<0.05). The concentrations of metals from high activity areas were higher than the concentrations from medium and low activity areas. The leaves were considered polluted as the concentrations of the metals except Ni exceeded permissible limits set by Rivers State Ministry of Environment. The levels of activity, ages and height of plant leaves influenced the concentrations of metals. Leaves should be properly treated before use for cooking and herbal or medicinal purposes.