2023 年 12 巻 2 号 p. 111-120
Activities involved with naturally occurring radioactive material (NORM) cover broad industrial sectors with very diverse characteristics. The main contributors to the NORM releases are mining and mineral processing industries. Releases from industries involving NORM are often produced in large amounts, but not well characterised radiologically; as a result, data are lacking to characterize public and worker exposures. The National Pollutant Release Inventory (NPRI) contains a total of 323 pollutants released to air, water and land from all industries in Canada. However, all major radionuclides from uranium and thorium series are not in the reporting list of NPRI. Given this constraint, this report advances our understanding of releases from NORM industries by describing the nature and magnitude of releases for pollutant substances reported in NPRI that are known to have naturally occurring radioactive isotopes other than in uranium and thorium series, and total particulate matters with great potential containing radionuclides from uranium and thorium series. The results indicate that NORM industries are responsible for almost all of the releases to air for the pollutant substances reviewed here: 100% for thallium and its compounds, 97% for lead and its compounds, 95% for cadmium and its compounds, 91% for selenium and its compounds, and 86% for total particulate matter (< 100μm).