Background Radiation Exposure in Transylvania, Romania: Environmental and Seasonal Influences

Background: Environmental ionizing radiation plays a major role in human radiation exposure. Natural background radiation originates from the Earth’s crust and outer space. The terrestrial component consists of primordial radioisotopes (40K, 238U, 235U, 232Th), as well as elements of the uranium and thorium decay chains, of which, from a dosimetric perspective, 222Rn and its decay products carry the greatest weight. These account for more than half of the crustal component. Cosmic radiation consists of gamma rays, X-rays, and particles such as protons, electrons, neutrons, mesons, and hyperons. Methods: The main objective of our research is to determine the background radiation levels characteristic of various regions of Transylvania. In addition, we aim to determine the effects of local environmental, diurnal, and seasonal changes on radiation levels. Results: A statistically significant difference was observed between the values of the individual regions (p < 0.001). The values we measured ranged from 0.051 µSv/h to 0.285 µSv/h. Based on the results, we can conclude that there is a statistically significant difference (p < 0.05) between the median value dropped after ventilation (0.159 µSv/h), compared to the one before ventilation (0.164 µSv/h). According to our database, radiation levels are significantly (p < 0.01) higher during the fall and winter months. Conclusions: On this basis, Transylvania can be regarded as a safe and livable region in terms of natural background radiation levels. Nevertheless, it is important to maintain a healthy lifestyle, ventilate homes frequently, and spend as much time as possible outdoors in nature.