Exhalation rate of radon-222 from concrete and cement mortar

Abstract

The main sources of radon in the air of dwellings are soil, building materials, and groundwater. This study aimed to determine the exhalation rate of 222Rn from samples made of concrete and cement mortars, as well as to evaluate by means of gamma spectrometry the hazard indexes associated with other radionuclides present in the studied samples of building materials. The results obtained allowed the comparison of the exhalation rate of radon using theoretical calculations based on one-dimensional and three-dimensional models. Measurements of the activity concentration of radon in air was performed by AlphaGuard radon detector. Furthermore, obtained results were compared with the measurements performed inside the concrete test cells. These test cells were built with the aim of simulating a dwelling in small dimensions and to evaluate indoor radon activity associated with concrete. Consequently, the obtained results of radon exhalation rate, in becquerel per meter squared per hour, for the concrete was 2.55 ± 0.03 Bq·h−1·m−2 for the 1D model and 0.461 ±0.008 Bq·h−1·m−2 for the 3D model. The exhalation rate of radon, for the cement mortar was 1.58 ± 0.03 Bq·h−1·m−2 for the 1D model and 0.439 ± 0.011 Bq·h−1·m−2 for the 3D model. The indoor concentration of 222Rn from the test cell was 112 ± 9 Bq/m3. These values were below the limit of 300 Bq/m3 recommended by the International Commission on Radiological Protection (ICRP) and <148 Bq/m3, the limit recommended by the US Environmental Protection Agency (US EPA). Even so, these values should be the subject of concern since that activity is related only to the contribution of concrete walls.

Radon Footprint From the Phosphogypsum Waste Stack Near Zgrpolci Locality, Veles, Republic North Macedonia

“…We obtained very similar findings when comparing the results for the exhalation of radon from phosphogypsum from the tailings near Zgrpolci compared to some building materials originating in Italy (tuff, pyroclastic flow, lapilli and cement; Tuccimei et al, 2009), where our measured values were higher in the range of 3 to 18 times. Without going any further into separate comparisons we would like to emphasize that the values of radon exhalation rates reported in Table 3 correspond well with the values reported by other authors (Rawat et al, 1991;Porstendörfer, 1994;Stoulos et al, 2003;Righi and Bruzzi, 2006;Perna et al, 2018). Also, we would like that radon exhalations from sampled phosphogypsum waste stack at Zrgopolci were approximately two times higher then respective ones in coals and related fly ashes from some part around the World (Singh et al, 2016) In regards to exhalation measurements of thoron from the phosphogypsum samples we are emphasizing that they showed range of values going from 7408.1 up to 20385.4 mBq • kg -1 h -1 and averaging 14457.5 mBq • kg -1 h -1 , from more than of 1530 cumulative measurements, also.…”

Radon and thoron exhalation rate, emanation factor and radioactivity risks of building materials of the Iberian Peninsula

“…No. of samples (Rawat et al, 1991;Porstendörfer, 1994;Stoulos, Manolopoulou & Papastefanou, 2003;Righi & Bruzzi, 2006;Perna et al, 2018). The variation in radon exhalation rates (one order of magnitude, in some cases) can be attributed to variations in radium concentrations, porosity, and surface crystallography.…”

Measurement of 222Rn Exhalation Rate from Natural Rubber Latex Pillows Randomed from Online Market in Thailand

“…Because radon exhalation rate is controlled by two main parameters: radon generation (containing radium in the sample) and transport through the solid matrix its porosity, grain size, material sample geometry, etc., one of the possible ways to measure the rate of exhalation from the material sample is by the measuring of the radon concentration in a closed chamber or container [5,[13][14]. The radon exhalation rate, E, which expresses per unit surface area (Bq m -2 h -1 ) of a natural material and radon concentration, C (Bq m -3 ) measured in a closed-chamber system are described by several authors [4,[15][16], according to Eq.…”

“…It is one of the potential dangerous radioactive elements, known to be the second cause of lung cancer in the general population after smoking [1]. It emits ionizing radiation and decays its short-lived progeny which are heavy metals such as polonium-218, lead-214, bismuth-214, polonium-214, lead-210, bismuth-210, polonium-210, and stable lead-206 [1][2][3][4][5][6][7]. When radon gas and its progeny attracted to particulates in air are inhaled by human beings, they are exhaled and remain in the lungs.…”

“…The radon is a major contributor to the annual effective dose from natural ionizing radiation [2,[5][6]. Because radon results from the natural decay of uranium, the main sources of which are in soils, rocks, plants, water, air, building materials, home accessories etc.…”