Longitudinal and transverse mobility of some heavy metals on receiving soils of dumpsites in Niger State, Nigeria.

Abstract

Population growth and Industrialization have caused the introduction of toxic substances into the agricultural soil from manufacturing processes as waste. This study describes the longitudinal and transverse mobility of this waste containing heavy metals from dumpsites to the surrounding environment of Niger state, Nigeria. Soil samples were collected within the dumpsites at distance of 10 m and 20 m away at three depths (5 cm, 15 cm and 30 cm) to assess the concentration and mobility of Cr, Fe, Mn, Pb, Zn, Cu and Al. The results show that heavy metals are more concentrated in the topsoil with significant migration down the slope, thereby posing a threat to groundwater quality. In the fractions, the concentrations of the metals follow this sequence: Mn>Fe>Cu>Zn>Cr>Al. The mobility factors of the heavy metals are significantly high indicating high potential mobility and bioavailable forms of these heavy metals. The high concentrations of the heavy metals particularly Cr, as observed in the study is as a result of anthropogenic activities on the enrichment of natural soil with bioavailable heavy metals. Consequently, there is a need to be cautious in the way waste that is generated from heavy metals sources is added to the natural soil.