Assessment of bioavailability and human health exposure risk to heavy metals in surface soils (Klang district, Malaysia)

© 2017, © 2017 Informa UK Limited, trading as Taylor & Francis Group. In urban area surface soil the heavy metal concentrations followed the order: Pb (76.15 mg/kg) > Fe (12.96 mg/kg) > Cu (11.58 mg/kg) > Al (10.3 mg/kg) > Zn (6.42 mg/kg) > Co (0.21 mg/kg) > Cd (0.18 mg/kg) > Cr (0.07 mg/kg). For the industrial area surface soil, heavy metal concentrations followed the sequence: Pb (55.28 mg/kg) > Al (15.5 mg/kg) > Fe (14.73 mg/kg)> Cu (14.68 mg/kg) > Zn (4.48 mg/kg) > Co (0.26 mg/kg) > Cr (0.11 mg/kg) > Cd (0.11 mg/kg). PCA output showed that the first and second principal components are attributed due to the presence of “urban metals” in the urban areas while third principal component reflects the anthropogenic factor in the industrial areas. Total Cancer Risk values are more than the incremental lifetime (1.0E − 05), showing the likelihood of a cancer threat for adults and children. For non-carcinogenic risks, Hazard Index values