Natural Radioactivity of Australian Building Materials, Industrial Wastes and By-products

TLDR

Natural radioactivity from 226Ra, 232Th, and 40K is present in conventional raw materials and some industrial wastes used in Australian building and ceramic industries. The authors quantified this radioactivity by gamma‑ray spectrometry and examined the effect of sieving to remove fines, which contain higher concentrations of radioactive nuclides. Most materials showed low radioactivity, but red mud, phosphogypsum, zircon products, and fly ash had higher levels that are unlikely to pose a health risk, and sieving fines can further reduce these levels.

Abstract

The natural radioactivity due to the presence of 226Ra, 232Th and 40K in conventional raw materials and some solid industrial wastes and by-products which are being used or have a potential for use in the building and ceramic industries in Australia has been measured by gamma-ray spectrometry. The majority of materials examined in this work showed fairly low levels of radioactivity. Some samples of red mud, phosphogypsum, zircon products and fly ash did show higher levels of radioactivity than would be acceptable on the basis of a criterion formula for gamma-ray activity suggested for use in some OECD countries. But this higher level of radioactivity should not pose an environmental health problem when these materials constitute a relatively small portion of the materials used in a normal building. The present work has also shown that the radioactivity levels of some of the materials can be reduced through the removal of fines by sieving, as the fines seem to contain a higher concentration of radioactive nuclides.