Indoor ²²²Rn concentration in the exhibition and storage rooms of Polish geological museums

The radon exhaled from radioactive mineral collections exhibited in five Polish geological museums may influence its total indoor concentration. Radon concentrations measured in the exhibition halls do not pose a risk for visitors or museum staff. However, air exceeding the action limit for workers (equal to 300 Bq/m³) was noted in the storage rooms of two museums. Significant²²²Rn activity concentrations equal to more than ~300 kBq/m³were measured inside lead containers where radioactive minerals were stored. - Highlights: • In this ²²²Rn radionuclide measurements in 5 Polish geological museums have been done. • The review of ²²²Rn activity in the air in areas containing radioactive geological collections is not a routine protocol, and is not included in the national radon monitoring program. • Therefore the radiological exposure for museum staff resulting from inhalation of gaseous radon and its products has been including.