Rational establishment of radon exposure standards for dwellings and workplaces

Background: Radon is a normally occurring radioactive material, which is designated as a class 1 human carcinogen. Therefore, it is important to control radon exposure in dwellings and workplaces. Methods: The radon guidelines of 32 countries across Europe, North America, and Asia were examined to determine rational radon exposure standards for minimizing radon risk in dwellings, offices, and workplaces. The exposure standards were classified as standards for people in dwellings and offices, where radon exposure can occur through construction materials, and standards for workers exposed to radon at industrial sites, where they directly handle products containing radioactive matter such as raw materials and by-products from processing. Results: The examination results showed that in South Korea, the advisory reference level (ARL) for dwellings is set to 148 Bq/m. Moreover, ARLs are set for subway stations, libraries, medical institutions, and indoor parking lots, but there are no radon exposure standards to protect workers in manufacturing sites, officers, and other workplaces. In other countries, the ARL or the mandatory reference level (MRL) are usually regulated between 148–400 Bq/m for dwellings and public-use facilities, and between 200–1,000 Bq/m for workplaces. Conclusion: It is recommended to use 148 Bq/m, which is the standard set by the U.S. Environmental Protection Agency, for dwellings and workplaces. For workplaces, it is recommended to set the exposure standard between 400 Bq/m, which is the level adopted in most European Union member countries, and 1,000 Bq/m3, which is the reference level recommended by the International Commission on Radiological Protection.