Human beings are constantly exposed to low levels of ionizing radiation from natural radiation sources. This natural background radiation exposure has the following main origins:
The lion's share of the dose from natural radiation sources is contributed by the radioactive noble gas radon and its derived products. Radon is not only odourless but also otherwise imperceptible to the human sense organs. In our surroundings, i.e. also in offices or office-like rooms, it is constantly present in greater or lesser concentrations. In general, the expected radiation exposure in offices is low and on the same level as the mean natural background radiation. Nevertheless, there are also cases in which the radon concentration in offices is elevated and above the mean value.
Report "Indoor workplaces"