EARLY USES OF RADIONUCLIDES IN MEXICO

Mexico is traditionally a mining country and the first information abo ut the presence of uranium is related to mine exploitation. Around 194 5, when uranium became economically important, a rumor spread that lar ge amounts of Oaxaca's black ceramics were being purchased and sent ab road because of their assumed high uranium content. It was not until 1 949 that minerals containing thorium and uranium were declared by law as ''national reserves''. In the 40's, a radium emanation plant was in stalled at the ''Hospital General'' in Mexico City with the main purpo se of carrying out radon seed implantation in tumors. In the 50's, a r adium dial-painting facility was operating in the city of Toluca. In 1 955, the National Commission of Nuclear Energy (CNEN) was founded by a government decree with two main activities: a training program on ''R adioisotope Techniques and Nuclear Instrumentation'' and the creation of specialized laboratories. In this paper, a general description of t hese events and undertakings spanning the decades from 1940 to 1970 is given.