Tracing Cement-Related Potentially Toxic Element Contamination in Soil and Associated Human Health Risks Using Spatial Analysis: Evidence from Bokajan, Northeast India

Potentially toxic element (PTE) contamination associated with cement manufacturing can affect soil quality and pose risks to human health. This study assessed the concentrations, spatial distribution, potential sources, and human health risks of selected PTEs in surface soils around the Bokajan cement factory. Thirty-six surface soil samples were analyzed for Pb, As, Cr, Co, Ni, and Zn using X-ray fluorescence. Mean concentrations of all PTEs were below Canadian soil quality guideline values (Cr = 57.56 < 64 mg kg−1; Zn = 54.28 < 200 mg kg−1; Ni = 22.61 < 50 mg kg−1; Pb = 10.00 < 70 mg kg−1; As = 9.00 < 12 mg kg−1; Co = 6.14 < 40 mg kg−1). Spatial distribution maps generated using the inverse distance weighting (IDW) method in ArcGIS 10.8.2 revealed elevated PTE contamination within 0–1.5 km of the factory. Health risks were assessed for adults and children following USEPA models across ingestion, inhalation, and dermal pathways. Ingestion was the dominant exposure route. One-way ANOVA, Pearson correlation analysis, and factor analysis revealed significant distance-dependent variation in PTE concentrations and indicated contributions from both anthropogenic and lithogenic sources. Cancer risks from Cr for adults (1.46 × 10−5) and children (5.18 × 10−6) exceeded the USEPA threshold (1 × 10−6), whereas As remained within acceptable limits. Noncarcinogenic risks were generally low, except for elevated HI values for As (adults: 1.25; children: 2.32) and Cr (children: 1.68). The findings indicate localized impacts of cement-related emissions on surrounding soils and provide baseline information for environmental monitoring and human health risk assessment in the Bokajan industrial region.