Radon ( 222 Rn) is a naturally occurring radioactive gas and a significant cause of lung cancer globally, second only to inhaled tobacco smoke. This review examines radon exposure in Japan, its public health risks, current regulations, and mitigation strategies in the context of international standards. Studies show that Japan's indoor radon concentrations average around 15 Bq m -3 , significantly lower than the global mean of approximately 40 Bq m -3 . Furthermore, only a small percentage, estimated at 0.1 to 1%, of Japanese homes exceed the World Health Organization's reference level of 100 Bq m -3 . As a result, radon is responsible for a smaller proportion of lung cancer cases in Japan, around 4%, compared to many Western countries. Nonetheless, radon remains an important public health concern, especially as modern homes become more airtight, potentially elevating indoor radon levels. The review also explores the geographic distribution of radon in Japan, highlighting regions (e.g., parts of western Japan with granitic bedrock) that exhibit higher natural radioactivity. It assesses the absence of a comprehensive national radon regulation in Japan, contrasting it with numerous countries that have established reference levels, building codes, and action plans. This review discusses effective radon mitigation techniques, including active soil depressurization and improved ventilation, applicable to Japan's building context. It argues for a proactive national radon policy to promote routine monitoring, public awareness, and remediation of high-radon homes. Finally, it proposes forming an association of radon scientists and technologists in Japan to enhance research, training, and policy advocacy.

Staff members in radiology departments face radiation exposure as a primary work-related risk according to safety guidelines. This research evaluates knowledge, attitudes, and practices (KAP) regarding radiological protection protocols of radiology workers in Jordan. The research employed a cross-sectional analysis using a questionnaire administered to 203 professionals from the groups of radiologists, medical physicists, radiologic technologists, and nurses. Among the participants, 44.3% held a bachelor's degree, 41.4% had a diploma (two-year technologist certification), and 14.4% held higher qualifications. The average knowledge score was 46%, with notable deficiencies in key areas such as radiation dose limits and tissue sensitivity. Attitudes towards radiation safety were generally positive, with scores ranging from 55.7% to 86.2%. However, inconsistent safety practices were observed, particularly in the use of personal protective equipment (PPE). Despite 87.19% using personal dosimeters, only 58.13% consistently used lead gloves, goggles, and thyroid collars, highlighting the need for further improvements. Staff members displayed inconsistent practices especially regarding their use of personal protective equipment during work shifts. Radiology professionals require specialized training programs which help raise compliance levels and foster safe practices in their work environment.

Magnetic resonance imaging (MRI) has revolutionized disease diagnosis and treatment. However, the technology poses safety risks, such as exposure to magnetic fields, RF pulses, and cryogens, necessitating strict adherence to safety protocols to protect patients and healthcare workers. This cross-sectional descriptive study assessed compliance with MRI safety standards in Khuzestan province, Iran) imaging centers, focusing on electromagnetic fields and other key safety domains. A 61-item researcher-developed checklist, based on international safety guidelines, was used to evaluate safety protocols in 11 MRI centers across seven domains, including facility design, equipment labeling, static magnetic and gradient fields, RF waves, cryogens, patient and staff protection, and infection control. MRI staff responded with yes/no answers. Responses to three additional questions also were collected. Data analysis was conducted using SPSS 26. A p-value < 0.05 was considered statistically significant. Overall, facility design scores ranged from 54.5% to 100%, but static magnetic field safety ratings were significantly lower (25% to 100%). Although safety equipment availability reached 100% in some centers, gaps were noted in labeling ferromagnetic devices. Infection control adherence was high, but only seven centers featured seamless flooring in the magnet room. Cryogen safety showed partial compliance with some centers lacking exhaust fans. Employee and patient safety measures were inconsistent, with one center scoring as low as 18%. While MRI centers demonstrated strengths in infection control and facility design, critical deficiencies in static magnetic field safety and emergency protocols highlight the need for targeted training, regular audits, and updated policies. Addressing these gaps is essential to enhancing MRI safety practices and aligning with international standards.

Those responsible for radiological protection in the workplace come to the role through many different pathways. In the process of training radiation safety officers and x-ray safety officers, instructors at the Radiation Safety Institute of Canada have observed that, while many course participants will have previous radiological protection training, it is common for a significant number to have experience managing traditional occupational health and safety or industrial hygiene programs and no radiological protection background. Humans use mental models or schemas to understand the world. They assimilate new information based on their existing schemas. Those formally trained in radiological protection are well versed in the International System of Radiological Protection, based on the fundamental principles of justification, optimization, and limitation as described in International Commission on Radiological Protection Publication 103. Those with training in occupational health and safety or industrial hygiene in Canada or the United States work within a framework called the hierarchy of controls. Given here is a comparison of these safety frameworks with consideration of how the health and safety schema of these two groups of radiological protection personnel may differ and areas on which to build a common understanding of radiological protection in the workplace. Hopefully, consideration of this topic will lead to improved communication and help safety professionals avoid misconceptions that might arise owing to differences in foundational knowledge.

Situational awareness is critical in radiological emergency response as it enables responders to understand and interpret real-time data to make informed decisions during high-stress situations. Effective situational awareness involves collecting accurate data on radiation levels, contamination zones, and potential exposure risks, and visualizing this data in a comprehensible format. Tools like RadResponder play a key role in this process by allowing users to assign severity levels to data records and view them on an event map, thus facilitating rapid and informed decision-making. The CRCPD E-43 committee has developed enhanced threshold sets for RadResponder to improve situational awareness during radiological incidents. These threshold sets, based on science and informed by nationally recognized reference documents or regulations, are designed to help responders quickly assess radiation levels and make informed decisions regarding public safety and emergency worker doses. By providing clear, easily identifiable values and a standardized approach to data visualization, these threshold sets enhance the effectiveness of radiological emergency response efforts. The committee also recommends upgrades to the RadResponder system for better visibility and management of threshold sets, ensuring responders can efficiently access vital information during emergencies.

Internal dosimetrists are concerned with the development, selection, and calibration of biokinetic models to calculate radiation doses from incorporated radionuclides. This is accomplished using measurements of radionuclides in organs, tissues, and excreta, i.e., bioassay measurements. Each bioassay measurement has a corresponding likelihood function, which represents the relative likelihood of different biokinetic model parameters resulting in the measurement value. In order for a bioassay measurement to be interpreted properly, the correct likelihood function must be determined. Failing to use the correct likelihood function for each bioassay measurement results in improperly weighting certain measurements over other measurements, which in turn leads to incorrect dose estimates. This paper describes the correct likelihood functions to use for a wide variety of bioassay measurements, as well as a description of how to use them. These likelihood functions represent the vast majority of those likely to be needed for interpreting bioassay measurements. Therefore, this paper may serve as a tool kit that can be used by academic and occupational internal dosimetrists.