Journal of Emerging Trends in Engineering and Applied Sciences: Research Areas

Abstract:
Abandoned dump sites are in particular vulnerable to heavy metal pollution. Hibiscus esculentus is one vegetable that is mostly cultivated on such sites and also commonly consumed in the study area. Uptake of heavy heavy metals by Okro (Hibiscus esculentus ) grown on abondoned dump sites in Effurun, Nigeria have been determined experimentally. Conentration of heavy metals (Zn, Pb, Cu, Fe, Ni and Hg) were experimentally investigated in soil samples collected from such sites and in Hisbiscus esculentus (stems, fruits and leaves). The soil samples showed elevated levels of the heavy metals Zn(59-214), Pb (0.9-4.2), Cu (301-714), Fe (712-2186), Ni (7.1-14.9) and Hg (0.61-1.14) expressed in mg/kg dry weight basis. The elemental concentrations in parts of the plant were generally low, with leaves having the highest levels of Zn, Cu, Fe, and Ni while stem contain the highest levels of Pb and Hg. Elemental values in the edible part (fruits) of the investigated plant were generally low and within statutory safe limits. Also results show that Tf of all the elements (heavy metals) were less than 1, indicating that heavy metal bioaccumulation has not taken place. The order of transfer factors is as follow: Zn > Ni > Pb > Fe> Hg> Cu. The study provided nutritional data on heavy metal composition Okro (Hibiscus esculentus) grown on abandoned dump sites and serves as a pathway for investigating how such elements enter the food chain and will finally be ingested by humans.

Keywords: heavy metals, okro (hibiscus esculentus), effurun, contaminated soil, transfer factor.

Download full paper