The September 1999 IAEA Bulletin edition focuses on the safety and security of radioactive material. Together with advancing the applications of nuclear techniques, the IAEA works to set and maintain international standards for safety and security of radiation sources and radioactive material, and helps Member States build capacity to comply with those standards. Medicine, industry, and defence uses have led to radioactive material falling out of regulatory control. Featured articles also report on illicit trafficking, on radiation safety and security in the United States and the European Union, on the International Commission on Radiation Protection (ICRP) guidance on potential radiation exposure, and provide a historical overview of radiation sources in the USA.