Source characterization of trace elements and assessment of heavy metal contamination in the soil around Tarabalo geothermal field, Odisha, India

Tarabalo geothermal area is one of the eight geothermal areas existing in the Indian state of Odisha. The present study aims to (i) understand the influence of thermal spring water and agricultural activities on the spatial distribution of trace elements in the soil, (ii) delineate the contamination of heavy metals, and (iii) identify the possible sources of trace elements in the soil. For these purposes, thermal spring water samples were collected from 9 locations and twenty soil samples were collected in a gridded pattern from the geothermal area. Trace elements such as As, Ba, Be, Cd, Co, Cr, Cu, Li, Mn, Mo, Pb, Sb, Se, Th, Tl, U, V, and Zn are considered in this study. The trace element concentrations in the soil show wide variation ranging from 0.02 (Be) to 931.4 mg/kg (Mn). The contribution from thermal spring water is considered to have a limited effect on the accumulation and distribution of trace elements. The values obtained from I geo , EF, and ERF to delineate contamination of heavy metals in the soil show that it is enriched with heavy metals such as As and Pb. Based on ERI values, the ecological risk caused by the concentration of heavy metals in the study area is low. Trace element concentrations in the soil are considered to be significantly from geogenic source and moderately from anthropogenic activities.