title: Non-carcinogenic and carcinogenic health risk assessment of selected metals in soil around a natural water reservoir, Pakistan.
abstract: Contaminants in surface soil can directly pose significant human health risks through oral ingestion, dermal contact and particle inhalation, especially for children. Both non-cancer and cancer risks associated with selected metal levels (Cd, Cr, Cu, Fe, Mn, Pb and Zn) were evaluated in surface soil around Mangla Lake during summer and winter. The results based on average pseudo-total metal concentrations followed the decreasing order: Fe (4038mg/kg)>Mn (394mg/kg)>Zn (40mg/kg)>Pb (17mg/kg)>Cr (21mg/kg)>Cu (15mg/kg)>Cd (1.3mg/kg) during summer and Fe (3673mg/kg)>Mn (407mg/kg)>Zn (30mg/kg)>Cr (26mg/kg)>Pb (26mg/kg)>Cu (14mg/kg)>Cd (1.8mg/kg) during winter. Present metal levels in the soil were also compared with other studies and guideline values which showed significant increase in the metal concentrations in this study. The metal levels also showed considerable spatial variations around the lake. The correlation study and multivariate principal component analysis revealed significant anthropogenic contributions of the metals in soils. Aqua-regia extractable (pseudo-total) contents were used as the reference to establish the percentage of bioavailability. After considering the bioavailability (Cd>Pb>Cr>Zn>Cu>Fe>Mn during both seasons), the non-cancer and cancer risks posed by Cd, Pb and Cr was relatively higher than rest of the metals, though the overall hazard index (HI) and cancer risk levels were within the safe limits (1.0 and 1.0E-06, respectively). The overall cancer risk to the adults based on pseudo-total metal concentrations exceeded the target value (1.0E-06), mainly contributed by Cr. A method considering bioavailability is suggested to produce a more realistic estimation for human health risks of trace metals contamination in soil.
authors.affiliation: Department of Chemistry, Quaid-i-Azam University, Islamabad 45320, Pakistan.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Saleem
authors.affiliation: Department of Chemistry, Quaid-i-Azam University, Islamabad 45320, Pakistan.
authors.forename: Javed
authors.initials: J
authors.lastname: Iqbal
authors.affiliation: Department of Chemistry, Quaid-i-Azam University, Islamabad 45320, Pakistan. Electronic address: mhshahg@qau.edu.pk.
authors.forename: Munir H
authors.initials: MH
authors.lastname: Shah
mesh_terms: D000328:Adult; D001682:Biological Availability; D002648:Child; D004784:Environmental Monitoring; D006801:Humans; D060106:Lakes; D019216:Metals, Heavy / Q000032:analysis* / Q000633:toxicity; D009369:Neoplasms / Q000139:chemically induced*; D010154:Pakistan; D025341:Principal Component Analysis; D018570:Risk Assessment; D012621:Seasons; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis* / Q000633:toxicity
chemical_list: D019216:Metals, Heavy; D012987:Soil; D012989:Soil Pollutants
keywords: Bioavailability; Exposure pathways; Mangla Lake; Metal; Multivariate analysis; Soil