Mutagenetic effects in mice exposed to radon-222 emissions in Latium region (Italy)

The aim of this work was to investigate the mutagenetic effects of the exposure to Radon-222 and its progeny in laboratory mice. In order to realize this objective, a study was carried out in two small towns, where Radon pollution is notoriously present. Six-week-old CD1 female mice, placed in cages, were located in the underground of three buildings in Ciampino (Rome) and in a cellar in Vetralla (Viterbo). They were exposed to natural emissions of Ra-don for 30 days. Radon-222 activity was measured both on a continuous basis using AWARE Corporation (U.S.A.) electronic detectors, and every 10 days using CR-39 closed detectors (U-series Srl., Italy). The micronucleus test, a sensitive mutagenicity test in vivo, was applied to the pe-ripheral blood of mice before exposure, and 10, 20, and 30 days after. Micronucleated erythrocyte frequencies were determined counting 2000 erythrocytes per animal. The results showed that in mice groups exposed to more than 700 kBqh-1/m3 of Radon-222, the micronuclei frequency was significantly higher than that observed before exposure. A significant correlation between micronuclei induction and increase of Radon exposure was observed. These pre-liminary results suggest that further investigation of the mutagenic properties of Radon and its progeny has to be carried out in order to establish a possible relationship with carcinogenesis.