Abstract Radon ( 222 Rn) has been highlighted by a number of authors as a significant public health concern. For example, it is the second most significant cause of lung cancer after tobacco smoking ( c. 1000–2000 and 21 000 deaths per year in the UK and USA, respectively), yet a very high proportion of the general public appears to be unaware of the risk. This chapter deals with topical radon issues, such as: radon in the workplace; radon in homes; exposure to radon during leisure activities; radon and water; measurement and monitoring; seasonal correction; remediation; cancer risks; cost–benefit analysis and cost-effectiveness; mapping; future policies; and further research. This assessment of the state of radon research is focused on the UK as an example of a country where radon has been on the governmental agenda since the late 1970s, but also highlights radon issues throughout the world in, for example, the USA, Europe and Asia.

Abstract Radon is generally regarded as a naturally occurring radiological hazard but we report here measurements of significant, hazardous radon concentrations that arise from man-made sources: for example, radium-dial watches. This study is an examination and assessment of health risks from radium and uranium found in historical artefacts, and the radon that emanates from them. This includes radium-dial watches, the main focus, plus clocks, aircraft instruments, and ornaments and artefacts made of uranium glass/uranium-glazed. Such objects were very popular in the 1930s and 1940s, and are still readily available today. A collection of 30 radium-dial pocket and wrist watches was measured and shown to be capable of giving rise to radon concentrations two orders of magnitude greater than the UK Domestic Action Level of 200 Bq m −3 in unventilated or poorly ventilated rooms. Furthermore, individual watches are capable of giving rise to radon concentrations in excess of the UK Domestic Action Level. We also highlight a gap in remediation protocols, which are focused on preventing radon entering buildings from outside, with regard to internally generated radon hazards. Radon as arising from man-made objects, such as radium-dial watches, should be considered appropriately in radon protocols and guidelines.