A Study of the Uptake of Heavy Metals by Plants near Metal-Scrap Dumpsite in Zaria, Nigeria

The research work investigates the metal uptake of the plants Lycopersicon esculentum (tomato), Rumex acetosa (sorrel), and Solanum melongena (garden egg) collected from experimental sites and a control area in Zaria, Nigeria. The concentrations of Cd, Cu, Fe, Pb, Mn, and Zn in different parts of each of the plant species grown on the experimental and control soils were determined using atomic absorption spectrophotometry. The experimental levels of the metals were higher than those at the control site and the limits recommended by Food and Agricultural Organisation/World Health Organisation (FAO/WHO). Solanum melongena showed bioaccumulation factor (BF) and transfer factor (TF) greater than 1 for Cd, Pb, and Mn; Rumex acetosa showed BF and TF greater than 1 for Mn and Zn, and TF was greater than 1 for Cu and Fe; Lycopersicon esculentum had only the TF for Fe, Pb, Mn, and Zn greater than 1. This results implies that Solanum melongena and Rumex acetosa plants can be effectively used for phytoremediation of Cd, Pb, Mn, and Zn from the dumpsite. Pearson’s correlation coefficient values were greater than 0.75 for all the metals studied which indicated that the high metal level in the experimental soil was a result of the metal-scrap.