Keywords: radon inhalation, survival, adaptive response, radon exposure, lung cancer, gamma irradiation, low radiation
Short-term radon inhalation induces significant survival adaptive response in Balb/c mice
According to the World Health Organization (WHO), the main health hazard from high radon exposure is an increased risk of lung cancer. In this study, 60 male Balb/c mice (20-30 g) were randomly divided into four groups of 15 animals. The animals in the 1st group were kept for 72 hours in an ordinary cage while the 2nd, 3rd, 4th groups were kept in cages with artificially elevated levels of Rn-220. Radon concentrations in the cages of the 1st, 2nd, 3rd and 4th groups were 19±3, 495±54, 590±110 and 1054±231 Bq m−3, respectively. After 72 h, all animals were whole-body irradiated with a previously reported Lethal Dose (LD) 50/6 of 8.8 Gy of cobalt-60 gamma radiation. Ten days after gamma irradiation, the survival fraction for the control group was 26.7%, while the 2nd, 3rd, and 4th groups had survival rates of 66.7%, 53.3% and 53.3%, respectively. After 15 days, the survival fraction for the control group was zero, while the 2nd, 3rd, and 4th groups had survival rates of 26.7%, 20.0% and 26.7%, respectively. These data clearly show that short-term exposure to elevated levels of radon may induce an adaptive response.