Arsenic variation in soil layers in Bandung Regency, Indonesia: A statistical approach for identifying potential sources

This research investigates the arsenic concentrations in 96 soil samples from a regency in Indonesia using a statistical approach. Soil samples were collected from three depth layers (topsoil [10-20 cm], subsoil [50-60 cm], and deep soil [90-100 cm]), with each layer consisting of 32 samples. Statistical analysis using SPSS was employed to analyze potential arsenic sources based on the proximity of study locations to geothermal system areas, land use, distance from industry, and the presence of study locations on fault lines. The findings indicate that the potential source of arsenic contamination in the soil are suspected to be associated with geothermal system activities and the presence of soil samples on fault lines. The arsenic concentration in locations near to the geothermal system (5-10 km) was 45 times higher (OR 1/4 45, 95% CI 1/4 45-362.57, p < 0.01). Arsenic was found to be 3.828 times higher in study areas situated on fault zones (OR 1/4 3.828, 95% CI 1/4 1.507-9.719, p < 0.01). Additionally, the research suggests that arsenic in the soil may also originate from anthropogenic activities, such as agriculture and industry, as the highest concentrations were found in subsoil or topsoil layers compared to deep soil. The variation in arsenic concentration from highest to lowest in agricultural soil layers was subsoil > topsoil > deep soil, whereas in residential soil, it was subsoil > deep soil > topsoil. The arsenic concentration variation at near distances from industrial areas was topsoil > subsoil > deep soil, contrasting with medium to far distances from industry (subsoil > deep soil > topsoil). Therefore, these findings can be utilized to prioritize remediation efforts and provide input for future research on arsenic contamination in the region. (c) 2024 The Authors. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co. Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).