Heavy metal contents in plants and soils in abandoned solid waste dumpsites in port Harcourt, Nigeria

Abstract

A study of heavy metal contents in plants and soils in two abandoned solid waste dumpsites alongside the controls located along East-west road (site 1) and Eastern by-pass (site 2) was conducted. A systematic sampling approach was used comprising total of 9 sample plots of 4 m2 each located on 3 line transects. The soil samples were collected at each plot using a soil auger at the depth of 0-15 cm. Dominant plant species were selected, uprooted and collected from each sample plot. Both plants and soil from each sample plot were analyzed for heavy metals [Zinc (Zn), Iron (Fe), Cadmium (Cd) and Lead (Pb)]. The results showed that there was an increase in the concentration of heavy metals in the two dumpsite soils than that of the soils at the control sites. The heavy metal (Fe and Zn) contents in the plants were higher at the dumpsites than control sites while the concentrations of Pb and Cd in the plants were higher at the dumpsite than control at site 1 (East-West road) and higher at the control site than dumpsite at site 2 (Eastern By-Pass) respectively. The level of heavy metals transfer for site 1 was in the order: Fe>Pb>Cd>Zn while for site 2 was Fe>Cd>Pb>Zn. Therefore, abandoned solid waste dumpsites contained high concentrations of heavy metals which are later absorbed and accumulated by plants growing at such sites.