Nano Particles Including Radon Decay Products in Ambient Air

Radon and Its Short-Lived Products in Indoor Air: Present Status and Perspectives

“…Median values and standard deviations (SD) of the maximum number concentration of aerosol particles (N M ) emitted during an indoor activity, the ratio between N M and background (N b ) aerosol concentration (N M /N b ), and the particle generation-emission rate (Q p ), measured in houses in the residential suburb of Brisbane, Australia by He et al [115]. Often, the highest particle concentration was exhibited by burning candles (not included in the above review); for instance, 241 mm −3 [234], 400−500 mm −3 [230], and 1200 mm −3 [235]. In contrast, candle burning was found by Hussein et al [111] to be the weakest particle source in comparison to smoking, frying, and using a stove and aroma lamp.…”

“…The role of the aerosol particles generated during cigarette smoking and candle burning on the behaviour of radon short-lived products in indoor air has been presented in more detail by results obtained in a basement kitchen of a family house in a suburban area in Ljubljana city, Slovenia [231,235]. For this purpose, activity concentrations of radon and its short-lived products in the unattached and attached form were measured using an EQF3020-2 (and seldom EQF3220) device (Sarad, Dresden, Germany), and the number concentration and size distribution of aerosol particles in the 5-530 nm size range were monitored with an SMPS + C instrument, Series 5.400, with the medium DMA unit (Grimm, Hamburg, Germany), as described in Section 6.3 Air Filtration.…”

“…In the three primordial radioactive chains, three radon isotopes are created by α-transformation of radium [1]: 222 Rn (half-life, t 1/2 = 3.82 days) in the uranium chain starting with 238 U, 220 Rn (t 1/2 = 55.6 s) in the thorium chain starting with 232 Th, and 219 Rn (t 1/2 = 3.9 s) in the actinium chain starting with 235 U (Figure 1). Only a fraction of radon atoms (emanation fraction or emanation power) succeed in leaving the mineral grain due to their recoil energy and thus enter the void space, from where they migrate through the medium either by diffusion or, more effectively and to longer distances, by being carried by gas or water [2].…”

Evaluating the impact of indoor aerosols on the performance of real-time radon sensors

“…Following decay, solid radionuclides rapidly react with vapors and trace gases to form unattached clusters in the size range 0.5-5 nm (Porstendörfer, 1994). The attachment process, influenced by aerosol sources such as cigarette smoke or cooking emissions, has been studied extensively (Porstendörfer, 1994;Vaupotic, 2011;Skubacz and Wołoszczuk, 2019), with findings indicating differing attachment rates based on aerosol size and composition (Porstendörfer, 1994). In enclosed indoor environments, surface deposition serves as the primary mechanism for reducing radon decay product concentrations, with studies indicating that higher aerosol concentrations result in reduced deposition rates (Porstendörfer, 1994).…”

“…The equilibrium factor F, representing the ratio between radon concentration and its progeny's equivalent concentrations plays an important role in assessing the impact of radon on human health (Vaupotic, 2011;Chen and Harley, 2018;ICRP, 2018). Dynamic processes in indoor environments, including the variable concentration of indoor aerosols, often lead to the absence of equilibrium between radon and its progeny (Chen and Harley, 2018).…”