Both natural and man-made sources of ionizing radiation contribute to human exposure and consequently pose a possible risk to human health. Much of this is unavoidable, e.g., natural background radiation, but as the use of radiation increases, so does the potential health risk and the public's concerns. This perspective reflects the authors' view of current issues in low dose radiation biology research, highlights some of the controversies therein, and suggests areas of future research to address both issues in low dose radiation research and the controversies. This is a critical time for the radiation sciences and the implications of future research will have a significant impact on radiation protection, medicine, national security, research and industry. The views expressed here are the authors' own and do not represent any institution, organization or funding body.