Just before the turn of the 20th century, the discoveries of X-rays, in 1895, and of radioactivity, in 1896, opened up whole new worlds of science. For the medical community, the world has been changing ever since, in some countries far more rapidly than in others.?The December 1994 IAEA Bulletin edition examines nuclear applications for health. Featured articles report on nuclear medicine, radiotracer technology, and applications in the fields of nutrition and environmental pollution. Moreover, the highlights of the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR)'s 1994 report on the effects of low doses of ionizing radiation are summarized. Articles also examine the transfer of nuclear technologies to developing countries organized by the IAEA and IAEA-supported trainings.