Assessment of trace metal contamination of soil in a landfill vicinity: A Southern Africa case study

Contamination of soils by trace elements is a worldwide concern and has negative effects on environmental sustainability. Geochemical assessment of soils using appropriate indicators and pollution indices has received much attention in recent years in efforts to rehabilitate this resource. This study quantified pollution of soils by trace elements at the Roundhill landfill, South Africa using indices and multivariate statistics. Soils were collected and assayed for trace metals using x-ray fluorescence. Pollution indices classified soil contamination levels while multivariate statistical analysis was conducted using principal component and cluster analyses. Findings showed that concentrations of all elements decreased with increasing distance from the landfill. Low to extremely high pollution was evident in all soils and Cr had the highest values compared to other elements. Negative correlation and weak clustering of Cr and Cd was associated with different wastes disposed at the landfill. Reported pollution in soils was associated with the influence of landfill leachate in the investigated area.