This study is aimed to estimate the skin dose due to presence of natural radionuclides in the Multani Mitti (MM, fuller's earth). The activity concentration of natural radionuclides is measured by using Canberra's HPGe detector model GC3020. The average activity concentration levels of 238U, 232Th and 40K are found to be 47, 71 and 748 Bq kg−1 respectively which are higher than corresponding world's median values 30, 35 and 400 Bq kg−1 as reported in Unscear 2000. Geant4 MC simulation is used to estimate skin doses arising due to application of MM on the skin. The decay chains for 238U and 232Th are simulated using Radioactive Decay Module (RDM) available in the Geant4, which automatically accounts for the all members of the decay chain and all types of radioactive emissions. The skin dose conversion factors for natural radionuclides in MM for 238U,232Th and 40K are found to be 0.5, 0.5 and 330 mGy MBq−1 hr−1. The main contribution to skin dose comes from 40K. The radiological health risks to miners and workers are evaluated by measuring radium equivalent activity, radiation hazard indices, annual absorbed dose rate, annual gonadal effective dose equivalent and annual effective dose equivalent. The values of annual absorbed dose rate, gonadal dose and annual effective dose equivalent are found higher than world's median values in the soil. Therefore, miners and workers dealing with MM are vulnerable to potential negative health effects of radiation exposure.

中文翻译：

---

使用 Geant4 Monte Carlo 模拟估计 Multani Mitti（富勒地球）的皮肤剂量


本研究旨在估计由于 Multani Mitti（MM，富勒土）中存在天然放射性核素而导致的皮肤剂量。天然放射性核素的活性浓度通过使用堪培拉的 HPGe 检测器型号 GC3020 进行测量。发现 238U、232Th 和 40K 的平均活性浓度水平分别为 47、71 和 748 Bq kg-1，高于 Unscear 2000 中报告的相应世界中位数 30、35 和 400 Bq kg-1。Geant4 MC 模拟用于估计由于在皮肤上应用 MM 而产生的皮肤剂量。238U 和 232Th 的衰变链是使用 Geant4 中提供的放射性衰变模块 （RDM） 进行模拟的，该模块自动考虑了衰变链的所有成员和所有类型的放射性发射。发现 238U、232Th 和 40K 的天然放射性核素（以 MM 为单位）的皮肤剂量转换因子为 0.5、0.5 和 330 mGy MBq-1 hr-1。对皮肤剂量的主要贡献来自 40K。通过测量镭当量活性、辐射危害指数、年吸收剂量率、年性腺有效剂量当量和年有效剂量当量来评估矿工和工人的放射健康风险。发现年吸收剂量率、性腺剂量和年有效剂量当量的值高于土壤中的世界中位数。因此，矿工和处理 MM 的工人容易受到辐射暴露对健康的潜在负面影响。