## 1 Introduction  
The increasing use of artificial radiation in medical institutions has increased radiation exposure in the diagnostic area [1]. Although the dose and quality of the radiation used for the diagnosis of diseases are relatively low compared to the radiation leaked from a nuclear accident, for example, even a very small dose can have a very dangerous effect on the human body [2]. Most of the radiation exposure that is a problem in medical institutions is caused by indirect scattered rays rather than direct rays. Scattered radiation corresponds to a low dose, generally less than 100 mSv [3]. In the case of radiation exposure of less than 100 mSv, the Research Council Biological Effects of Ionizing Radiation report (BEIR VII) supports the theory of linear proportion without a threshold, thus, there is a direct potential for cancer and genetic disorders [4, 5]. Therefore, the active protection of medical workers against low-dose radiation exposure is critical. Current radiation shielding clothing in medical institutions generally uses lead as the shielding material, however, the weight of this substance hinders the physical activity of medical staff and patients. A radiation protection apron having the equivalent to 0.50 mm of lead weighs between 3.01 and 3.15 kg. Because the front part offers protection from the shoulders to the knees, these are widely used in the vicinity of X-rays in medical institutions [6]. A previous study considered that scattered rays exist within 2 m of the radiation generating site, and for this purpose, suggested a shield with a thickness of less than 0.50 mm of lead equivalent [7]. However, in order to reduce the weight of the shielding lining, it is necessary to discover a new shielding material, and this is also related to the manufacturing process technology that is used to replace the shielding material, hence there are many complications in practical use. Recently, radiation shields have been developed using eco-friendly materials to avoid the toxicity of lead. Eco-friendly radiation shielding materials consist of tungsten, bismuth, barium sulfate, and boron, among others, mixed with a polymer material and manufactured in the form of a sheet [8; 9]. Any shielding suit used in a medical institution must be lightweight and safe [10]. In order to maintain the same shielding performance for direct X-rays, it is difficult to significantly change the weight of the shield. However, since the scattered radiation generated in a certain distance and direction has a low dose, it can be shielded with lightweight shielding clothing. Radiation shielding involves absorption using a material made of an element with a large atomic number, such as lead, or reducing the transmission of radiation through interaction with the shielding material. Therefore, lowering the amount of radiation exposure requires selecting a shielding material considering the type and energy of the radiation [11]. In the low energy region of X-rays or \(\gamma\)-rays with high radiation transmittance, sufficient shielding effect can be obtained with relatively thin lead, but in the high energy region, the necessary protective effect cannot be obtained unless the shield is thickened [12]. However, if the thickness of the shield is increased sufficiently, the weight of the shielding suit also increases substantially, which hinders the activity of medical personnel who must wear it for a long time during work. In this study, PE yarn was wound around a tungsten wire to fabricate a shielding fiber that can be used as a lining for lightweight shielding clothing. The study also developed an air pressure dispersion process to disperse nanotungsten powder to eliminate pinholes in fibers. The shielding performance and weight of the fibers were evaluated to determine the potential efficiency of the fibers in low-dose shielding suits used in medical institutions.