Natural and anthropogenic origin of metallic contamination and health risk assessment: A hydro-geochemical study of Sehwan Sharif, Pakistan

Chemosphere. 2022 Aug:300:134611. doi: 10.1016/j.chemosphere.2022.134611. Epub 2022 Apr 15.

Abstract

Heavy metal contamination in groundwater is a serious threat to the environment and therefore its proper monitoring is a matter of great concern these days. In the present research, groundwater samples from Sehwan Sharif district Jamshoro, Pakistan were collected to estimate the concentration of various elements including potentially hazardous metals. Statistical analysis of the collected data based on Pearson co-relation metal clustering and Principal Component Analysis (PCA) divides the elements into three groups; Group I contains As, Cu, Ni, and Cd, Group II contains Mn, Fe, B, and Cr and Group III contains Pb and Zn. The elements Cu, Ni, As, Pb, Cd, and Zn found with higher RSD values demonstrate their anthropogenic origin whereas the lower concentration of Mn, Fe, B, and Cr indicate their natural origin (Tepanosyan et al., 2016). The histograms and box-plots of Mn, Fe, B and Cr were found normally distributed while abnormal for Cu, Ni, Pb, As, Cd and Zn. The HQs of these elements indicate their non-carcinogenic risks. However, results of individual metallic behavior indicate the highest HQ measured for B followed by HQs for Cu, and As. The toxic effects of investigated metal (loid)s calculated using HI were found to be 1.58 for adults and 1.35 for the child which is considered the medium chromic risk and cancer risk. About the toxicity of these heavy metals, their cancer risk was assessed on the levels of Cd, As, and Cr in groundwater. The carcinogenic risk of As was found to be 2.78 × 10-4 and 1.62 × 10-3 for child and adult, respectively. Furthermore, the values of this carcinogenic risk are 2.64 × 10-6 and 1.54 × 10-5 for Cd while 4.24 × 10-3 and 2.48 × 10-2 for Cr in child and adult, respectively. Since cancer risk exceeded the target risk of 1 × 10-4 for As and Cr in adults and children, it can thus be considered 'non-acceptable'. The Geographic Information System (GIS) based maps were prepared using Inverse Distance Weighted (IDW) interpolation which showed the Spatial distribution of all elements throughout Sehwan Sharif from different sources of environment. Spatial maps of elements produced by ArcGIS show the hotspots of potentially hazardous elements such as the highest concentration of Pb, As, Zn, Cu, Ni, and Cd were found in urban areas of Sehwan Sharif district Jamshoro, Pakistan.

Keywords: Groundwater; Health risk assessment; Heavy metal; Sehwan sharif; Spatial maps.

MeSH terms

  • Adult
  • Cadmium / analysis
  • Carcinogens / analysis
  • Child
  • Environmental Monitoring / methods
  • Humans
  • Lead / analysis
  • Metals, Heavy* / analysis
  • Metals, Heavy* / toxicity
  • Neoplasms*
  • Pakistan
  • Risk Assessment

Substances

  • Carcinogens
  • Metals, Heavy
  • Cadmium
  • Lead