Polyvinyl alcohol composites (PVA) with added Pb, Bi, and Sn: A study on radiation shielding and gamma ray attenuation

Lead (Pb) is widely used for radiation shielding due to its high atomic number, density, affordability, and availability. However, its toxicity poses serious environmental and health risks. This study aims to evaluate the gamma-ray shielding performance of polyvinyl alcohol (PVA)-based shielding composites in the attenuation of 60 Co, 137 Cs, and 241 Am sources. A PVA-based shielding material incorporating Pb, Bi 2 O 3 , and Sn were evaluated for its radiation attenuation properties, using Pb as the benchmark standard for comparison of shielding effectiveness. PVA was selected for its hydrophilicity, ease of mixing, and light-weight property. A total of 18 shielding samples were fabricated, with 6 samples for each metal. The variables include metal percentages of 10%, 20%, and 30%, as well as thicknesses of 0.6, 0.8, and 1.0 cm. Pb composites showed the highest attenuation among all samples, while Bi 2 O 3 and Sn composites also demonstrated strong shielding performance. The results showed that increasing the metal percentage per unit thickness has a much greater effect on shielding performance than simply increasing thickness. Increasing metal percentage at constant thickness significantly increases both linear and mass attenuation coefficients for all samples while reducing their HVL. At a constant thickness of 0.8 cm, increasing the metal composition from 10% to 30% results in a rise in the linear attenuation coefficient. For PVA/Pb, it increases from 1.75 cm -1 to 2.7 cm -1 , for PVA/Bi 2 O 3 , from 1.8 cm -1 to 1.9 cm -1 , and for PVA/Sn, from 1.3 cm -1 to 1.5 cm -1 .In summary, optimal shielding efficiency is primarily determined by the metal percentage per unit thickness, as photon attenuation depends more on the concentration of heavy atoms along the radiation path than on overall sample thickness. • PVA/Pb is the best shielding followed by PVA/Bi while PVA/Sn is less effective at high energies. • At 0.8 cm, raising metal from 10% to 30% boosts attenuation by up to 20%. • At 20% metal, increasing thickness from 0.6 to 1.0 cm improves attenuation by 10–15%. • Higher metal content means higher number of atoms to absorb radiation per unit path • Maximizing metal per thickness gives the most effective shielding.