Abstract

The deposition of radioactive aerosols from radon daughter, which are potentially harmful to human health. The inhalation of short-lived radon decay products (RnPs) yields the greatest contribution to natural radiation exposure. This research deals with a study carried out to improve the knowledge of the behaviour of RnPs, their interaction with particulates and the plate-out during the time. The tests confirmed that a high aerosol particle concentration increases the probability that an ion sticks to aerosol and remains long in the air, leading to both an increase in equilibrium factor (F) and a decrease of unattached fraction (f_p). The results performed in a radon calibration chamber (free of particles) showed a reduction of F (and the average of ~ 0.1 %) because in an environment the plate-out phenomenon prevails over the attachment to particulate. Besides, the high circulation fan speed (~2.9 ms^-1) in the radon calibration chamber has been a more significant effect on the plate-out of attached radon progeny (~0.040±0.002 Bq cm^-2h^-1).

Keywords:Radon decay products; Plate-out; EERC