Distribution, correlation, ecological and health risk assessment of heavy metal contamination in surface soils around an industrial area, Hyderabad, India

In recent years, much concern has been addressed over the soil contamination with heavy metals due to rapid industrialization and urbanization. The present study was conducted to investigate distribution of potentially hazardous elements (PHEs) (As, Cr, Cu, Ni, Pb and Zn) concentration in soils of Kazipalli, Hyderabad, India. Soil samples from fifty-seven (57) sampling sites were collected from in and around industrial zone and were analysed for their heavy metal contents. Concentrations ranged from 4.4 to 796.3 mg/kg for As, 9.7 to 598.6 mg/kg for Cr, 7.9 to 183.5 mg/kg for Cu, 10.2 to 129.6 mg/kg for Ni, 25.3 to 1830 mg/kg for Pb and 23.8 to 879 mg/kg for Zn. Application of Pearson’s correlation, factor and cluster analysis indicates that heavy metal contamination in soils originates from industrial activities which are of anthropogenic origin. Contamination of soils in the study area was further classified for geoaccumulation index, enrichment factor, contamination factor and contamination degree. The values of pollution index and integrated pollution index indicated that metal pollution levels were in order of As > Pb > Cu > Cr > Zn > Ni. Potential ecological risk indices (PERI, RI) and health risk assessment based on Hazard Quotient, Hazard index and on Average daily doses of individual elements were calculated using exposure parameters for resident population and references from integrated database of USEPA. These results are important for the development of proper management strategies to decrease point and non-point source of pollution by studying different remediation methods.