Understanding the Heavy Metal Contamination in Soil: A Comprehensive Risk Assessment

Abstract

Urban soil contamination by heavy metals poses a significant environmental and public health challenge. As an assessment of four heavy metals in urban soils of Hyderabad, Pakistan, employing spatial variability mapping, geographic information system (GIS), and multivariate analysis. A total of 415 soil samples were collected from different urban areas, processed, and analyzed using inductively coupled plasma-optical emission spectroscopy (ICP-OES). The results revealed distinct groups of elements, with Cd, Pb, and Zn displaying anthropogenic origins, while As showed natural abundance. GIS-based maps identified metal contamination hotspots, with Zn and Pb concentrations elevated in the city center, primarily attributed to vehicular emissions. The study also highlighted Ni hotspots in industrial areas and the Phulleli canal. The potential ecological risk (PER) assessment indicated moderate and considerable risk only for Cd. Integrated PER analysis revealed that 95% of samples had low PER, emphasizing the importance of these findings for guiding future urban planning and research and development activities. This comprehensive assessment provides valuable insights for policymakers, government authorities, and stakeholders to address and mitigate heavy metal contamination in urban soils.