Exposure of workers in Tusnica coal mine.
The aim of this paper is to identify potential exposure of the workers in the coal mine Tusnica. The results of the investigation showed increased activity of brown coal up to 1060 ± 88 Bq kg(-1) for (238)U, 976 ± 30 Bq kg(-1) for (226)Ra and 118 ± 31 Bq kg(-1) for (232)Th. Dose rate measurements ranged from 0.07 to 0.25 µSv h(-1). The annual effective dose, taking into account external exposure to ambient gamma radiation and internal exposure due to inhalation of the resuspended dust, would be 1.6 mSv a(-1). The results presented lead to the conclusion that Tusnica coal mine contains brown coal with significant radioactivity, indicating that the working hours in the area should be regulated and the use of respiratory protective equipment is obligatory.