ASSESSMENT OF HEAVY METALS IN DUMPSITE SOIL

ABSTRACT

The importance of the soil to the living organisms cannot be overemphasised. However, contamination of the soil is a problem which affects its functionality and quality. This study assessed the concentrations of heavy metals in soil from a dumpsite and plants grown in the soil in comparison with that from an uncontaminated farmland. Samples were collected and physicochemical and heavy metal analysis were carried out through standard analytical procedures. The results of the study showed that the pH of the dumpsite soil was highly basic (9.11). For the heavy metals iron had the highest concentration in all soil samples both before and after planting (19.50mg/kg and 3.53mg/kg), while cadmium had the least concentration as it was below detection limits in all samples. The heavy metal concentrations in the dumpsite soil were higher than those in the farmland soil, although all were within WHO/FAO limits. Heavy metal concentrations were much higher in plant rots than in the roots or stems with iron having the highest concentration (2.53mg/kg in stem - 6.51mg/kg in roots), while cadmium was not detected in any of the plant samples. All concentrations were also within WHO/FAO limits. It was also revealed that the plants grown in the farmland soils grew to greater lengths than those of the dumpsite soil, suggesting that the presence of heavy metals in soil could affect the growth of plants. It was then concluded that the heavy metal concentrations in the soil and plants of this study did not pose a threat to environmental and human health.