Experimental Evaluation and EGSnrc Monte Carlo Modeling of Barium Sulfate Cement Composites for Sustainable Diagnostic X-Ray Shielding

Abstract

The demand for non-toxic radiation shielding materials has intensified significantly due to severe environmental hazards, strict disposal regulations, and occupational health concerns associated with traditional lead-based protective barriers. Recent advances in composite material engineering have demonstrated that utilizing heavy mineral matrices enriched with barium sulfate (BaSO₄) can serve as a highly effective, chemically stable, and eco-friendly attenuator for ionizing radiation, particularly across diagnostic medical X-ray energy spectra. In this study, BaSO₄-cement composites were engineered and fabricated with a fixed filler concentration of 50% by weight and cast into multiple thickness profiles ranging from 0.2 cm to 1.0 cm. To evaluate their shielding efficacy, the fabricated composite blocks were exposed to typical clinical diagnostic radiation beams operating at low-energy (46 kV, 10 mAs) and high-energy (70 kV, 32 mAs) windows. To validate the physical measurements and establish a reliable framework for predictive barrier engineering, full-scale photon transport simulations were computationally executed utilizing the EGSnrc (Electron Gamma Shower) Monte Carlo software package. The experimental results revealed a sharp decrease in the transmitted radiation dose as a function of increasing sample thickness, showing exceptional alignment with the EGSnrc simulated attenuation profiles. Under the high-energy spectrum (70 kV), the 1.0 cm thick sample demonstrated the highest shielding performance, reducing the transmitted dose rate from a baseline of 442 μSv/h down to 26.1 μSv/h, which corresponds to an empirical attenuation efficiency exceeding 94%. Under low-energy conditions (46 kV), the same 1.0 cm configuration achieved near-complete beam absorption, letting through a negligible dose rate of only 0.99 μSv/h (99.58 % shielding efficiency). The computational EGSnrc models tracked these curves closely, yielding minimal relative deviations of +2.76 % and +3.13 % for the 1.0 cm sample at 70 kV and 46 kV, respectively. Higher relative deviations observed in the thinnest sample (0.2 cm at 46 kV, yielding +13.42 %) were elucidated via high-resolution fluoroscopic and X-ray diffraction (XRD) analyses, which revealed that microscopic structural inhomogeneities and casting voids in thin sections alter localized attenuation pathways compared to idealized, zero-porosity simulation media. Beyond technical shielding metrics, this study highlights the substantial economic and environmental advantages of utilizing locally available natural barite resources—such as those found in Libya—to fabricate sustainable structural shields for healthcare infrastructure. Collectively, these verified experimental and computational findings confirm the structural feasibility and predictive reliability of BaSO₄-cement composites as a high-performance, non-toxic, and economically sustainable alternative to conventional lead partitions in modern diagnostic radiology departments.