Overview of national regulatory approaches to assess worker’s exposure to radon in industries involving norm

National regulations address the radiological protection of industrial processes involving Naturally Occurring Radioactive Material (NORM), each with different approach. A collection of information gathered by members of the International Radiation Protection Association task group on “NORM” helps identify key differences in regulatory strategies. The main findings indicate that, while national regulations generally implement the requirements of international standards—and, for EU Member States, the provisions of European Commission directives—and consider ICRP recommendations, the regulatory approaches and protocols for managing worker exposure to radon in workplaces involving NORM vary significantly. In most countries, industrial processes involving NORM are regulated as planned exposure situations, whereas exposure to radon in workplaces is typically managed as an existing exposure situation. When radon doses need to be assessed because requirements for planned exposure situations apply, national regulations often require that these contributions be recorded and treated separately. However, in several countries, the contribution from radon inhalation is explicitly incorporated into the total effective dose assessment. In certain cases, the calculation specifically accounts only for the radon exposure attributable to the handling of NORM, excluding background or unrelated sources. The methodology for estimating radon doses can vary significantly between countries. There is a lack of harmonisation in the physical quantities used for assessment, as well as in the values of dose conversion factors.