Geochemical characterization and human health risk assessment of arsenic in soils of a high background area (Lori region, Armenia)

The adverse effects of arsenic (As) on human health highlight the importance of studying As concentrations, distribution patterns, and behavior in the environment, especially in regions with naturally elevated As levels. This study presents an integrated geochemical and spatial analysis of As in the soils of the Lori region (Armenia), a historically industrialized area with known mining influence. The goal of this study is to investigate the spatial distribution of As, identify its potential origin, unveil its geochemical associations with other major and trace elements, and assess As-associated health risk. Using energy-dispersive X-ray fluorescence spectroscopy, concentrations of As, along with Cr, V, Ti, Zn, Cu, Co, Fe, Mn, Ba, and Pb were analyzed in diverse soil types of the region. The mean As levels in the region exceeded the Upper Continental Crust and global soil averages by 3.6 and 3.1 times, respectively. Among the studied soil types, Acrisols exhibited a relatively high coefficient of variation (>60 %, reaching 76 %). The contamination was localized and primarily linked to mining and industrial emissions. Principal Component Analysis (PCA) and k-means clustering revealed a geochemical association of As with Zn and Pb covering the central and northern part of the region, near Pb and Zn mining sites. These results suggest that elevated As levels result from a superposition of natural geological and anthropogenic input. Three baseline values of As were established, which can serve as reference points for long-term environmental monitoring. Furthermore, a health risk assessment indicates a non-carcinogenic risk for children at three locations and a precautionary level lifetime carcinogenic risk (10^-6-10^-4) across the entire region for both males and females. The study results provide valuable baseline geochemical data for future comparative studies. The integrated approach used in this study offers a replicable framework for studying other high-background or contaminated areas globally.