Analysis of Long-Term Monitoring of Radon Levels in a Low-Ventilated, Semi-Underground Laboratory—Dose Estimation and Exploration of Potential Earthquake Precursors

This study involves continuous radon monitoring during the academic year 2023/2024. An Airthings Corentium Home radon detector placed in the basement laboratory of a faculty building in Kosovska Mitrovica (N 42.897°, E 20.867°) was used for continuous measurements. The average radon concentration was 303 Bq/m3, and a seasonal pattern during the measuring period was observed. For the first time, the results were grouped by week, excluding non-working days, to present a real case scenario with the aim of assessing the radon exposure of students, teachers, and employed persons. The inhalation dose from radon (1.54 mSv) was very high considering that exposure occurred in both semesters. Another aspect of continuous radon monitoring was to explore the relationship between indoor radon measurements and the occurrences of earthquakes in the Balkan region. Daily variations in radon (peaks and differences) were analyzed at the monitoring site by using both empirical laws and taking into account the earthquake data set provided by the Seismological Survey of Serbia. The analysis revealed that the events chosen to confirm a clear association between earthquake occurrence and enhanced radon activities in the air(as a precursor of seismic activities) did not meet the required criteria but most likely reflected external meteorological conditions.