Vertical distribution of heavy metals in Karewa deposits of South Kashmir: environmental contamination and health risk assessment

Thirty six soil samples from twelve well developed soil profiles were collected from Karewa Deposits of South Kashmir and analyzed for heavy metals including As, Cr, Pb, Cu, Ni, Cd, Zn and Co to assess the vertical distribution of heavy metals and their effects on environment and human health. The concentration of heavy metals decreases in the order as Cr > Zn > Ni > Cu > Pb > Co > As > Cd. The enrichment factor (EF) of As ranges from 3.35 to 8.52 with an average of 5.54 indicating moderate to moderately severe pollution of soils. However, the EF of other heavy metals ranged from 0.31 to 3.9, indicating negligible to moderate enrichment. The ecological risk index (ERI) ranged from 69.30 to 198.003 with an average of 124.89 indicating low to moderate ecological risk. Along the soil profiles, heavy metals, EF and ERI exhibit more or less similar trend, first decreases from soil C to regolith and then increases towards the topsoil of the profiles except for Pb, which decreases from bottom to top. In both children and adult, the sequence of the distinctive exposures for non-carcinogenic and carcinogenic doses in soils were in the order as ingestion > dermal > inhalation. The total hazard index (THI) of heavy metals were < 1, indicating negligible non-carcinogenic risks to children and adult. However, the total carcinogenic risks (TCR) of As for adults and As and Cr for children were higher than threshold value of 1.0E-04 indicating chromium and arsenic pose high carcinogenic risks to the inhabitants of South Kashmir, India.