Environmental Evaluation of Soil in Drosh-Shishi Valley Chitral, Pakistan: An Analysis of Potentially Toxic Metals and Associated Ecological and Health Risks

The issue of soil pollution has become a prominent concern especially in developing countries. The Drosh-Shishi Valley, a rug terrain near Afghanistan spanning approximately 15,000 square kilometers, is situated in the southern part of the Chitral District in North Pakistan and is inhabited by around 450,000 people. Presently, there is a growing exploration of ore minerals in this region, specifically contributing heavy metals that pose potential risks to human health. The primary objective of this study was to investigate potential sources of heavy metal dispersion from the exploration sites and the flash flood channels to assess the levels of these contaminants in soil, with a particular emphasis on the associated global health risks. We collected 34 representative samples from transported sediments and 31 from agricultural crops, analyzing them for the presence of Cd, Co, Cr, Cu, Mn, Ni, Pb, and Zn using ICP-OES (Agilent, 5110,USA) analyzers. These values were then utilized to determine the contamination factor (CF) and estimate the potential health risks posed by heavy metals, employing the USEPA dose–response model. In terms of concentrations, most metals, with the exception of Pb, exceeded permissible levels, displaying CF values ranging from moderate to high. In a broader health context, Cu and Ni emerged as significant contributors to a total cancer risk (TCR > 1 × 10−4) in children. This study concludes that heavy metal contamination poses a serious threat to human well-being in the Drosh-Shishi Valley and District Chitral emphasizing the need of implementing strict policy by authorities in monitoring soil heavy metal content to mitigate potential health risks.