Metal bioaccumulation and translocation studies of Spinacea oleraceae and Celosia argentea cultivated on contaminated soil

The quest for tolerant plants with excellent phytoremediation potential is a stark reality. Additionally, the use of dumpsite soil for growing vegetables and ornamental plants is relatively a common practice by farmers in urban cities across Nigeria. Hinged on these concerns, this study was poised to evaluate and compare the bioaccumulation factor (BAF) and translocation factor (TF) of Zn, Cu, Cr, Pb and Ni in two common vegetable species (Spinacea oleraceae and Celosia argentea) grown on the experimented Olusosun dumpsite soil and the undisturbed sandy loam top soils of the University of Lagos biological garden. The latter represents the control group. This study observed a considerable increase in metallic concentrations in the vegetable species grown on Olusosun dumpsite soil in comparison to the control. The level of Zn, Cu and Ni (except for Pb and Cr) were within the FAO/WHO permissible limit. Both vegetable species experimented on Olusosun dumpsite soil have BAFs <1 for Zn, Cu, Cr, Pb and Ni implying that they never accumulated those metals in their tissues. Likewise, both vegetable species have TF<1 in the order of Zn>Pb>Ni>Cu>Cr for Celosia argentia and Zn>Cu>Cr>Pb>Ni for Spinacea oleraceae. The use of dumpsite soil for growing vegetables have increased the levels of Pb, Cu, Zn, Ni, Cd, and Cr in their different parts and may further pose a serious threat to human health in the future if such practice continues.