Contamination assessment and potential human health risks of heavy metals in Klang urban soils: a preliminary study

Urban areas with rapid industrial development have major impacts on environmental soil quality. This study was carried out to determine contamination assessment of heavy metal concentration of urban soil from Klang district (Malaysia). Health risk assessment was used to determine potential health risks (carcinogenic and non-carcinogenic risks) in both adults and children. Moreover, this study was also used to identify the most significant contaminant and exposure pathway with regard to Klang urban soil. Mean bioavailability of heavy metal concentrations were found in the order of Fe (6.65 mg/kg) > Zn (5.61 mg/kg) > Cu (2.96 mg/kg) > Co (0.22 mg/kg) > Cd (0.14 mg/kg) > Pb (0.11 mg/kg) > Cr (0.10 mg/kg). Maximum values of Cd (0.64 mg/kg), Cu (52.14 mg/kg) and Pb (9.18 mg/kg) have exceeded some guidelines and standard values. Study findings showed that total carcinogenic risks values of Cd, Cr and Pb are more than incremental lifetime (1.0E-05). This indicates the likehood of having cancer threat for adults and children. While for total non-carcinogenic risk, none of the heavy metals (Co, Cr, Cu, Pb and Zn) showed Hazard Index values more than one indicating there is no any potential non-carcinogenic risks for adults and children in study area. From this study, Cd is the most significant contaminant as maximum concentration value has exceeded soil guidelines and potential to have carcinogenic risks to adults and children. Pathway order for both carcinogenic and non-carcinogenic risks is ingestion > dermal > inhalation where ingestion pathway contributed the most to potential health risks involving urban soil of Klang.