The present study investigates the impact of various body postures on dose assessment. Existing radiation protection systems that assume a standing posture are generally valid in most situations; however, they may not be effective in assessing the dose received by individuals in specific conditions such as radiation accidents. To address this, we used the Geant4 simulation code and mesh-type reference computational phantoms (MRCPs) to model and calculate the dose conversion coefficients (DCCs) for 19 representative working postures. These representative postures were developed by referencing existing industrial posture categories, combining movements of arms, torso, and legs. The exposure geometries considered in the present study include generalized parallel beams such as anterior-posterior (AP), posterior-anterior (PA), left-lateral (LLAT), and right-lateral (RLAT), and isotropic exposures from all sides (rotational (ROT) and isotropic (ISO)), along with semi-isotropic forms of ground and ceiling contamination ranging from 30 cm to 50 m in radius. The results demonstrate that the dose ratios between a personal dosimeter and whole-body (i.e. DCCs) are significantly influenced by the body posture and the exposure geometry. Particularly, exposures involving significant body shielding, such as ground and ceiling contamination and PA direction exposures, were mainly affected by the degree of torso bending. For instance, a DCC of 2.3 was recorded for a posture with approximately 45 degrees of torso bending under PA exposure. Additionally, in a ground contamination scenario having a 1 m radius beam, DCCs ranged from 0.8 to 2.5 depending on the degree of torso bending, and in a 2 m radius ceiling contamination scenario, DCCs of 1.2–1.7 were observed in postures with 90 degrees of torso bending. These findings emphasize the importance of posture-specific dose assessments in various contamination scenarios.

中文翻译：

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计算各种姿势下放射工作人员的剂量转换系数


本研究调查了各种身体姿势对剂量评估的影响。采取站立姿势的现有辐射防护系统在大多数情况下通常有效;但是，它们可能无法有效评估个体在特定情况下（例如辐射事故）接受的剂量。为了解决这个问题，我们使用 Geant4 仿真代码和网格型参考计算模型 （MRCP） 来建模和计算 19 种代表性工作姿势的剂量转换系数 （DCC）。这些代表性姿势是通过参考现有的工业姿势类别，结合手臂、躯干和腿部的运动而开发的。本研究中考虑的暴露几何形状包括广义平行光束，例如前后 （AP）、后-前 （PA）、左侧 （LLAT） 和右侧 （RLAT），以及来自各个侧面的各向同性暴露（旋转 （ROT） 和各向同性 （ISO）），以及半径为 30 cm 至 50 m 的半各向同性地面和天花板污染形式。结果表明，个人剂量计和全身（即 DCC）之间的剂量比受身体姿势和暴露几何形状的显着影响。特别是，涉及大量身体屏蔽的暴露，例如地面和天花板污染以及 PA 方向暴露，主要受躯干弯曲程度的影响。例如，在 PA 暴露下躯干弯曲约 45 度的姿势记录了 2.3 的 DCC。此外，在半径为 1 m 的梁的地面污染场景中，DCC 范围为 0.8 至 2.5，具体取决于躯干弯曲的程度，而在 2 m 半径的天花板污染情况下，DCC 为 1.2-1。在躯干弯曲 90 度的姿势中观察到 7 例。这些发现强调了在各种污染情况下姿势特异性剂量评估的重要性。