Radiological risk assessment and hazard indices of rhyolite volcano: a case study based on natural radionuclide concentrations and dose evaluation parameters

The present investigation looks at the radiological risks posed by rhyolite volcano through an evaluation of petrographic characteristics, natural radioactivity in 35 samples through laboratory gamma-ray spectrometry. The dominant components of rhyolite are quartz, K-feldspar, and plagioclase; however, accessory minerals present were zircon, thorite, and cassiterite. Activity concentrations of ²³⁸U, ²³²Th, and ⁴⁰K ranged from 275 to 833 Bq kg⁻¹, 2477 to 4976 Bq kg⁻¹, and 698 to 1714 Bq kg⁻¹, respectively. Radiological indices were computed from the activity concentration results, which also identified ²³²Th and ²³⁸U as the principle radiological risk contributors. Statistical analyses found strong associations between ²³²Th and the radiological indices. The results of this investigation demonstrate the utility of combining petrographic integrating with radiological measurements for the assessment of health and environmental risks.