Professor John Roderick Cameron's Influence on Radiation Safety in Terrestrial and Space Environments.

Professor John Roderick Cameron (1922-2005) stands out as a trailblazer in the field of medical physics, whose innovative work has deeply influenced radiation protection and the broader medical radiation field through sound technical judgment and insight. Best known for inventing the bone densitometry device, his pioneering efforts have reshaped modern medical practices far beyond his initial breakthroughs. Cameron's explorations extended into the realms of space biomedical science and models of terrestrial radiation, areas where his insights continue to resonate today. As the Emeritus Professor of Medical Physics at the University of Wisconsin-Madison and a founding member of the American Association of Physicists in Medicine, Cameron laid crucial groundwork for safety standards in environments with high natural radiation levels. His leadership was instrumental in advancing thermoluminescence dosimetry, radiation measurement, and image quality assurance, driving progress in both academia and clinical practices. Moreover, through establishing Medical Physics Publishing, Cameron played a pivotal role in spreading vital research and educational materials across the fields of health physics and medical physics. This commentary reflects on Cameron's far-reaching contributions, highlighting his critical work in space radiation research and terrestrial radiation models-key to the future of interplanetary travel and potential human settlement on planets like Mars. His research in areas of high background radiation, like Ramsar, Iran, has been fundamental in developing strategies for biological protection in space, which are essential for ensuring astronaut safety during long-duration space missions. We honor Professor Cameron's profound legacy, celebrating his visionary spirit and the lasting impact of his contributions on generations of scientists in radiation science.