Development of Medical Radiation Shield Using Density-Enhanced Recycled Oyster Shells

Abstract

As radiation-based techniques become an increasingly important tool for medical diagnostics, medical professionals face an increasing risk from the long-term effects of scattered radiation exposure. Although existing radiation-shielding products used in medicine are traditionally lead-based, recently, attention has turned to the development of more eco-friendly materials such as tungsten, bismuth, and barium sulfate. To date, however, the proposed alternative materials have struggled to compete with lead in terms of shielding performance and economic feasibility. This study explores the potential of radiation shielding materials based on the shells of bivalve mollusks such as oysters that are discarded from aquaculture, thereby preventing them from going to landfill. In addition, a firing process for enhancing the shielding performance of the original material is proposed. Experiments showed that shielding sheets comprising 0.3-mm-thick layers of oyster shell achieve a shielding efficiency of 37.32% for the low-energy X-rays typically encountered in medical institutions. In addition, the shielding performance was improved by increasing the density of the powdered oyster shell via plastic working at 1,200°C. This raises the possibility of developing multi-material radiation shields and highlights a new potential avenue for recycling aquacultural waste.