Effect of indoor-generated airborne particles on radon progeny dynamics

• Published in: Journal of hazardous materials Vol. 314; pp. 155 - 163
• Main Authors: Trassierra, C. Vargas, Stabile, L., Cardellini, F., Morawska, L., Buonanno, G.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15.08.2016
• Subjects: Airborne particles; Coils; Combustion; Dynamics; Equilibrium factor; Indoor air quality; Particle decay; Progeny; Radon; Radon levels; Radon progeny; Surface area; Airborne particles; Radon progeny; Equilibrium factor; Radon; Indoor air quality
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2016.04.051

•Investigation of the interaction between particles and radon progeny dynamics.•Measurements of particles emitted by different indoor sources.•Tests performed in a controlled radon chamber.•Particle size strongly influences the radon progeny dynamics.•Particle surface area concentration is the key parameter of the radon-particle interaction. In order to investigate the interaction between radon progeny and particles, an experimental campaign was carried out in a radon chamber at the Italian National Institute of Ionizing Radiation Metrology, quantifying the amount of attached and unattached radon daughters present in air, as well as the equilibrium factor in the presence of particles generated through indoor sources. A fixed radon concentration was maintained, while particles were generated using incense sticks, mosquito coils and gas combustion. Aerosols were characterized in terms of particle concentrations and size distributions. Simultaneously, radon concentration and attached/unattached potential alpha energy concentration in the air were continuously monitored by two different devices, based on alpha spectroscopy techniques. The presence of particles was found to affect the attached fraction of radon decay products, in such a way that the particles acted as a sink for radionuclides. In terms of sources which emit large particles (e.g. incense, mosquito coils), which greatly increase particle surface area concentrations, the Equilibrium Factor was found to double with respect to the background level before particle generation sessions. On the contrary, the radon decay product dynamics were not influenced by gas combustion processes, mainly due to the small surface area of the particles emitted.