1. NATURAL RADIATION DUE TO RADON. CASE STUDY: RADON CONCENTRATION IN HOUSES FROM APUSENI MOUNTAINS. Authors: PETRONELA DAVID, BETY-DENISSA BURGHELE, MIRCEA CLAUDIU MOLDOVAN, NICOLETA BICAN-BRIȘAN.2. INDOOR RADON RELATED WITH THE GEOLOGY IN ROMANIAN URBAN AGGLOMERATIONS (CLUJ-NAPOCA). Authors: ALEXANDRA CUCOȘ, CARLOS SAINZ, GABRIEL DOBREI, TEOFANA SFERLE, ANDREEA RĂCHIȘAN, CRISTINA HORJU-DEAC, ARTHUR TUNYAGI, TIBERIU CATALINA, ANDREI ISTRATE, SIMION BELDEAN, BOTOND PAPP, ANCA ȚENTER, KINGA SZACSVAI, MIRCEA MOLDOVAN, BETY-DENISSA BURGHELE, TIBERIUS DICU, ȘTEFAN FLORICĂ.