Assessment of the Efficiency of Red and Brown Clay Slabs as a Radiation Protection Material

Background: Effective shielding is bottom line of radiation protection in diagnostic radiology. Lead and concrete traditionally used for radiation shielding, have environmental, health and cost limitations. Clays, being mast abundant and variable in composition may serve as viable alternatives if their attenuation properties are well characterized.

Aim: This study aimed to determine the attenuation coefficients of brown and red clay at varying thicknesses under X-ray interaction (75 keV) and a constant density (2.353 g/cm3 and 2.632 g/cm3 for brown and red clay respectively) at a constant distance of 2m, to compare their relative efficiency and to assess their suitability for radiation shielding compared with standard materials.

Materials and methods:  An experimental design was used. Clay slabs of thicknesses 5–24 cm (brown) and 5–28 cm (red) were prepared at densities of 2.35 g/cm³ and 2.63 g/cm³, respectively. A 75 keV X-ray source was directed through the slabs at a distance of 2m, and transmitted intensities were measured. Attenuation parameters (µ, µ/ρ, HVL, MHVL) were calculated. Statistical analysis included descriptive statistics and independent sample t-tests.

Results: Brown clay recorded µ values of 0.041–0.067 cm⁻¹ (mean 0.0535 ± 0.0085), HVL 10.3–16.8 cm (mean 13.25 ± 2.14), and MHVL 31.17 ± 5.04 g/cm². Red clay recorded µ values of 0.017–0.044 cm⁻¹ (mean 0.0353 ± 0.0100), HVL 15.8–40.7 cm (mean 21.82 ± 9.51), and MHVL 57.43 ± 25.02 g/cm². Differences in µ (p = 0.007) and MHVL (p = 0.030) were significant.

Conclusion: Compared with literature, brown clay aligned with concrete, while red clay was less effective. Brown clay outperforms red clay due to its higher iron-rich content and may serve as an eco-friendly alternative to concrete for structural shielding. Narrow-beam validated studies, compositional analyses, and clay-composite development are recommended. Iron-rich clays should be considered for sustainable secondary shielding in diagnostic radiology.