Assessment of the Spatial Distribution of Heavy Metal Contamination of Soils Surrounding the Ghori Cement Factory Using the Contamination Factor (CF) Index

Abstract

Soil contamination with heavy metals, particularly around cement factories, is among the most pressing environmental and public health concerns. This study aimed to assess the contamination of surface soils surrounding the Ghori Cement Factory, which has operated for years without due consideration of its environmental impacts. The concentrations and contamination levels of heavy metals, including mercury (Hg), arsenic (As), cadmium (Cd), lead (Pb), chromium (Cr), nickel (Ni), cobalt (Co), and aluminum (Al), were examined. Seventeen soil samples were collected from inside and around the factory based on prevailing wind directions. The samples were chemically digested following the international standard method (ISO 11466), and metal concentrations were measured using atomic absorption spectrophotometry.The degree of soil contamination was assessed using the Contamination Factor (CF) index. The results showed that aluminum, nickel, chromium, and cobalt levels indicated low contamination, while lead and cadmium reflected moderate contamination. Arsenic and mercury exhibited high to very high contamination levels. The highest CF value was observed for mercury, with an average exceeding 14, indicating very severe contamination. The increasing CF values toward the southeast direction of the factory and proximity to the pollution source highlight the direct impact of industrial activities on soil contamination. This severe contamination poses potential environmental and health risks, emphasizing the need for effective monitoring and control measures.