Skip top navigation

Dose Estimation and Radon Action Level Problems Due to Nanosize Radon Progeny

One of the essential parameters influencing of the dose conversion factor is the ratio of unattached shortlived radon progeny. This may differ from the value identified for indoor conditions when considering
special workplaces such as mines. Inevitably, application of the dose conversion factors used in surface
workplaces considerably reduces the reliability of dose estimation in the case of mines.

This paper surveyed the concentration of radon and its short-lived radon progeny and identified the
unattached fraction of short-lived radon progeny. As well equilibrium factor during the month of August
was calculated simultaneously at two extraction faces in a manganese ore mine.

During working hours the average radon concentrations were 220 Bq m3 and 530 Bq m3 at Faces 1
and 2; the average short-lived progeny concentration was 90 Bq m3 and 190 Bq m3, the average
equilibrium factors were 0.46 and 0.36, and the average unattached fractions were 0.21 and 0.17,
respectively. The calculated dose conversion factor was between 9 and 27 mSv WLM1, but higher values could also be possible.