Environmental radioactivity and radiological hazard assessment of soil samples from Rajasthan, India

This study presents a comprehensive assessment of natural radioactivity and the associated radiological risk parameters in soil samples collected from the state of Rajasthan, India. A total of 119 soil samples were collected from distinct locations across the region. The activity concentrations of naturally occurring radionuclides ²²⁶Ra, ²³²Th, and ⁴⁰K were measured using a High-Purity Germanium (HPGe) based gamma-ray spectrometry system. The activity concentrations (in Bq kg^-1) in the sample ranged from 15.2 ± 1.7 to 48.9 ± 2.2 for ²²⁶Ra, 21.3 ± 2.5 to 89.2 ± 2.6 for ²³²Th and 321.8 ± 15.5 to 955.9 ± 26.4 for ⁴⁰K, with mean values of 27.1 ± 1.8, 47.2 ± 1.7 and 517.3 ± 18.1 Bq kg^-1 respectively. Radiological hazard indices, including the radium equivalent activity, external and internal hazard indexes and annual effective dose equivalent, were calculated to evaluate the potential health risks. All estimated values were found to be within the safety limits recommended by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). The findings indicate that the levels of natural radioactivity in Rajasthan soils are comparable to global average values and do not pose significant radiological exposure. This study contributes valuable baseline data for environmental monitoring and radiological risk assessment in the region.