Heavy metal Contamination and Ecological Risk Assessment of soil around open landfill and dump site in Lafia metropolis and its potential impact on environment and urban community.

The study was aimed at determining the status of heavy metal Contamination and Ecological Risk Assessment of soil around open landfill and dump site in Lafia metropolis and its potential impact on environment and urban community. Soil samples were collected from different landfill and dumpsites in Lafia metropolis at the depth of 0 – 30 cm. The analysis for heavy metal was conducted using Atomic Absorption Spectrometer (AAS). The result of heavy metals across sampling sites in Lafia indicated the mean order of heavy metal concentration as Zn>Fe>Al>Mn>Pb>Cu>Ni>Se>As>Hg respectively. The levels of concentration of these metals varied across soil sampling points. The pollution indices such as Contamination factor (CF), Pollution load index (PLI), Contamination degree (Cd), Potential contamination index (Cp), potential ecological risk index (RI) were used for the metal enrichment and contamination status. The CF, Cd, Cp, PLI and RI value of the present work indicating that the soils of these sites are not polluted by heavy metals. The mean order of heavy metal concentration in plant samples are Fe>Zn>Mn >AL> Pb >Cu>Cr>Ni >As>Hg respectively. The result showed a wide range of values in the various elements measured. The heavy metal (Fe and Zn) contents in the plants were higher compared to other metals in all the sites. The concentration of some metal was relatively high in the maize plant, but they were all below the WHO permissible limit except for Zn metal. The transfer factor (Tf) revealed that plants grown on dumpsite and landfill soils absorbed and accumulates heavy metals. The highest transfer factor value was obtained in Fe, followed by Cu, Pb, Zn, Al, Mn, Ni and As respectively. The correlation analysis indicates significant negative correlation in soil and significantly and positively in plant of metals. The concentration of heavy metal indicated that the study area does not posed high risk to local community but the odour from the land fill and dumping site pollute the air which causes respiratory problems. Hence, this open landfill should be closed or properly managed by recycling in order to minimize future pollution problems.