Reflections on the impact of advances in the assessment of genetic risks of exposure to ionizing radiation on international radiation protection recommendations between the mid-1950s and the present.

Efforts at protecting people against the harmful effects of radiation had their beginnings in the early 1900s with the intent of protecting individuals in medicine and associated professions. Such efforts remain vital for all of us more than 100 years later as part of our 'learning to live with ionizing radiation.' The field of radiation protection has evolved slowly over time with advances in knowledge on hereditary (i.e., genetic) and carcinogenic effects of radiation continually improving our ability to make informed judgments about how best to balance risks against benefits of radiation exposure. This paper examines just one aspect of these efforts, namely, how advances in knowledge of genetic effects of radiation have impacted on the recommendations of the International Commission on Radiological Protection (ICRP). The focus is on the period from the mid-1950s (when genetic risk estimates were first made) to 2007. This article offers a detailed historical analysis and personal perspective, and concludes with a synopsis of key developments in radiation protection.