en Radiation Biology Radiation Biology تحقيق بديع Original Research <p style="text-align: justify;"><strong>Background:</strong> It has recently been shown that the particle size of materials used for radiation shielding can affect the magnitude of radiation attenuation. Over the past years, application of nano-structured materials in radiation shielding has attracted attention world-wide. The purpose of this study was to investigate the shielding properties of the lead-free shields containing micro and nano-sized WO3 against low energy x-rays. <strong>Materials and Methods:</strong> The radiation shields were constructed using nano and micro WO3 particles incorporated into an EPVC polymer matrix. The attenuation coefficients of the designed shields were evaluated for low energy x-rays (diagnostic radiology energy range).&nbsp;<strong>Results:</strong> The results indicate that nano-structured WO3/PVC shields have higher photon attenuation properties compared to those of the micro-sized samples. <strong>Conclusion:</strong> Our experiment clearly shows that the smaller size of nano-structured WO3 particles can guarantee a better radiation shielding property. However, it is too early to draw any conclusion on the possible mechanisms of enhanced attenuation of nano-sized WO3 particles.</p> <p></p> Radiation, attenuation, micro, Nano, WO3, in diagnostic radiology, X-ray 127 131 http://ijrr.com/browse.php?a_code=A-10-1-608&slc_lang=en&sid=1 A. Aghaz 790031947532846008061 790031947532846008061 No Shiraz University R. Faghihi 790031947532846008062 790031947532846008062 No Shiraz University S.M.J. Mortazavi mmortazavi@sums.ac.ir 790031947532846008063 790031947532846008063 Yes Shiraz University of Medical Sciences A. Haghparast 790031947532846008064 790031947532846008064 No Kermanshah University of Medical Sciences S. Mehdizadeh 790031947532846008065 790031947532846008065 No Shiraz University S. Sina 790031947532846008066 790031947532846008066 No Shiraz University