Potentially toxic metals in the petroleum waste contaminated soils lead to human and ecological risks in Potwar and Kohat Plateau, Pakistan: Application of multistatistical approaches

Until recently scant attention has been paid to assess the total concentration of potentially toxic metals (PTMs) in petroleum waste are more likely because once they enter in to the soils may become a source of contamination. This study investigated the concentrations of PTMs in soils of Potwar and Kohat plateau, Pakistan. Remarkable increase in the total concentrations of Cd, Cu, Mn, Ni and Pb were found in petroleum waste contaminated soils. Multi-statistical techniques such as Pearson correlation matrix analysis (PCMA) and principal component analysis (PCA) were used to establish a hypothesis that petroleum waste is a source of PTMs contamination in soils. The result of PCMA and PCA techniques confirmed that among PTMs, Cd followed by Mn was greatly whereas Zn and Pb were least affected by petroleum waste contamination in the soils. Ecological risk assessment was evaluated via contamination factor (CF), pollution load index (PLI), Nemerow integrated pollution index (NIPI), and ecological risk indexes (ERI). CF showed moderate contamination of soil with PTMs whereas Cd was found to cause high ecological risk to the surrounding environment. Enrichment factor (EF) was found in decreasing order as: Cd>Mn>Co>Cr>Cu>Ni> Zn> and Pb. Human health risk assessment in term of chronic daily intake (CDIingestion, CDIdermal, CDIinhalation), hazard quotient (HQ(ingestion), HQ(dermal), HQ(inhalation)), hazard index (HI) and total hazard risk index (THRI) of PTMs were evaluated for both child and adult indicating non-carcinogenic risk (NCR) value >= 1. (C) 2021 Elsevier B.V. All rights reserved.