Uptake of Heavy Metals by Plant Leaves around Industrial and Agricultural Areas of Enugu State, Southeastern, Nigeria

This research was carried out to determine the quantity of uptake of trace elements by the leaf of plants growing around industrial and agricultural areas of Enugu State. A total of twenty-two (22) plant leaf samples which consist of 12 different species such as S. pyramidalis, Py. polystachyos, Se. sesban, C. odorata, P. foetida, H. suaveolens, T. platycarpa, C. mucunoids, C. digitalis, D. aegypticum, Sc. dulcis and L. oryza sativa were collected from dumpsites, industrial sites, wetlands, mining sites and sewage site, across the study area. The samples were analyzed for heavy metals using standard laboratory methods. Results obtained in the study area revealed that the plant leaf samples obtained from the study area contained the following mean values: Fe3+ (25.69 ± 21.04 mg/kg), Mn (11.03 ± 0.64 mg/kg), As (4.60 ± 1.56 mg/kg), Pb (3.38 ± 1.46 mg/kg), Zn (21.93 ± 11.02 mg/kg), Cd (0.79 ± 0.03 mg/kg), Cr (2.86 ± 4.84 mg/kg), Ni (0.53 ± 4.27 mg/kg) and Cu (12.74 ± 2.89 mg/kg). The mean concentrations of iron, arsenic, lead, cadmium and chromium were above the recommendable limits as stipulated by FAO/WHO for edible plants. Principal component analyses of the variables revealed strong relationship among the variables indicating same source of enrichment. This study is limited to plant leaves; hence, further research is recommended in the study area to evaluate the uptake of heavy metals by the roots and stems of the same plants.