Abstract: Since 1958,the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) has regularly and repeatedly evaluated the levels of medical, occupational, and public exposures to ionizing radiation from both natural and artificial sources, and the exposure trends over time. UNSCEAR’s evaluations provide an independent, objective and up to date scientific basis for radiation safety. Countries and international organizations draw on the UNSCEAR’s scientific evaluations for developing protection programmes, legal instruments and policies for using technologies employing ionizing radiation. This article briefly summarizes the latest UNSCEAR evaluations on medical, occupational, and public exposure to ionizing radiation, and elaborates on the importance of full participation of United Nations member states in future UNSCEAR radiation level surveys and assessments.

Key words: UNSCEAR, medical exposure, occupational exposure, public exposure, exposure evaluation