Geochemical Assessment of Arsenic in Water, Soil, and Sediment and Its Bioaccumulation Relationship in Human Hair, Bardsir Area, Urumieh–Dokhtar Magmatic Belt
Subject Areas : Petrologyراحله هاتفی 1 , farhad Asadian 2 , zahra boosalik 3 , batoul janjaneh 4
1 - Iranian Academic Center for Education, Culture and Research (ACECR), Mashhad Branch, Iran.
2 - 2. Environmental Geology Department, Research Institute of Applied Science, Shahid Beheshti Branch, Iran
3 - 2. Environmental Geology Department, Research Institute of Applied Science, Shahid Beheshti Branch, Iran
4 - 2. Environmental Geology Department, Research Institute of Applied Science, Shahid Beheshti Branch, Iran
Keywords: Arsenic, Environmental Geochemistry, Human Hair Biomarker, Bardsir.,
Abstract :
This study investigates the geochemical behavior of arsenic in environmental media (water, soil, and sediment) and its bioaccumulation in human hair in the Bardsir region, located within the Urumieh–Dokhtar volcanic–plutonic belt of southeastern Iran. A total of 240 samples—including 100 water, 68 soil, 21 sediment, and 102 human hair samples—were collected and analyzed using ICP–MS. The average arsenic concentrations in water, soil, and sediment were 66 µg/L, 7 mg/kg, and 5 mg/kg, respectively. In parts of the groundwater, arsenic exceeded the WHO guideline value (10 µg/L), indicating geogenic contamination derived from altered and sulfide-bearing volcanic rocks. Approximately 61% of the hair samples contained arsenic at levels above the natural background (1 mg/kg), suggesting chronic exposure of the local population. Correlation and regression analyses revealed a stronger association between arsenic in hair and water (r = 0.48, R² = 0.23) than with soil (r = 0.25, R² = 0.06) or sediment (r = 0.14, R² = 0.02), indicating that groundwater is the primary pathway of arsenic transfer to humans. Geochemically, reducing aquifer conditions (Eh −100 to −200 mV), alkaline pH (9–10), and the presence of permeable NW–SE faults enhance arsenic mobility as As (III). The results indicate that arsenic contamination in the Bardsir area is mainly geogenic, controlled by geological and hydrogeochemical factors, with a clear link to bioaccumulation in humans. This study demonstrates the necessity of continuous groundwater monitoring in altered and volcanic terrains of Iran to mitigate geochemical and public health risks.
