Spatial distribution of potentially toxic elements in urban soils of Abbottabad city, (N Pakistan): Evaluation for potential risk

Abstract

Potentially toxic elements (PTE) are one of the main sources of soil toxicity with detrimental impacts on the environment due to their persistence, perseverance, and potential health risks. This study investigated the PTE such as nickel (Ni), lead (Pb), cadmium (Cd), cobalt (Co), iron (Fe), manganese (Mn), copper (Cu) and zinc (Zn) contaminations in urban soils of Abbottabad city, (N Pakistan). For this purpose, soils from different land types were collected and assayed for PTE level using atomic absorption spectrometry. Results showed relatively higher Fe and lower Cd contamination. The contamination factor (Cf), pollution load index (PLI) and ecological risk index (ERI) of pollution quantification factors were determined for PTE contamination. Results showed the relatively high Cf values for Ni and low for Pb. The PLI crossed the threshold of 1 in 40% of sampling sites, indicating significant PTE contamination at those sites. The ERI indicated low to considerable risk of PTE contamination across all sampling sites. The PTE were evaluated for carcinogenic and non-carcinogenic risks via ingestion, inhalation and dermal pathways. Health index (HI) values of 1.48E-02 and 1.18E-02 and cancer risk (CR) values of 9.39E-09 and 2.03E-04 were found for adults and children, respectively. Potential sources of PTE were quantitatively allocated by principal component analysis (PCA) along with geo-spatial analysis, indicating natural and anthropogenic inputs.