Emanation of Radon From Household Granite

Abstract

Emanation of radon (222Rn) from granite used for countertops and mantels was measured with continuous and integrating radon monitors. Each of the 24 granite samples emitted a measurable amount of radon. Of the two analytical methods that utilized electret-based detectors, one measured the flux of radon from the granite surfaces, and the other one measured radon levels in a glass jar containing granite cores. Additional methods that were applied utilized alpha-scintillation cells and a continuous radon monitor. Measured radon flux from the granites ranged from 2 to 310 mBq m-2 s-1, with most granites emitting <20 mBq m-2 s-1. Emanation of radon from granites encapsulated in airtight containers produced equilibrium concentrations ranging from <0.01 to 11 Bq kg-1 when alpha-scintillation cells were used, and from <0.01 to 4.0 Bq kg-1 when the continuous radon monitor was used.

Radon exhalation from building materials for decorative use

“…It can be concluded that under normal ventilation in a kitchen granite countertops contribute very little to the radon concentration for the range of radon exhalation rates reported here. Similar assessments were reported in the literature (Kitto and Green, 2005;Allen et al, 2009;Alvarcz et al, 2009;Kitto et al, 2009).…”

A radiological study of some ornamental stones: the bluish granites from Extremadura (Spain)

“…Our findings agree with the fact that not all granites can be "demonized" as being highly radioactive, as several authors have suggested (e.g. Kitto et al, 2009). There are different kinds of granites and it has to be taken into account both the mineralogy of the granite and quantity that is used in house building (Pavlidou et al, 2006).…”

Assessing exposure to granite countertops—part 1: Radiation

“…In addition, the identity and geographic origin of the stones included in this study is not known precisely because naming practices for granite are not standardized (Anjos et al, 2005). Nonetheless, the activity concentrations for 40 K, and the 232 Th and 226 Ra series observed in these stones are within the range reported for granite building materials in the scientific literature (Mustonen, 1984;NCRP, 1987a;Mustapha et al, 1997;Chowdhury, Alam and Ahmed, 1998;European Commission, 1999;Lee, Kim, Lee and Kang, 2001;IAEA, 2003;Kumar, Sengupta and Prasada, 2003;Arafa, 2004;Ahmed, 2005;ICRP, 2005;Al-Saleh and Al-Berzan, 2007;El-Taher, Uosif and Orabi, 2007;Lu, Wang, Jia and Wang, 2007;Ghosh et al, 2008;Kitto, Haines and Diaz Arauzo, 2008;Mujahid et al, 2008). Therefore, these samples of granite intended for use as interior work surfaces contain amounts of naturally occurring radioactive materials that are similar to levels in other types of granite building materials reported in the literature for which larger numbers of samples have been examined.…”

“…A number of studies have reported on the concentrations of natural radionuclides (i.e., activity concentrations) for granite samples obtained from Egypt, Saudi Arabia, Pakistan, South Korea, China, Brazil, Kenya, and Finland (Mustonen, 1984;NCRP, 1987a;Mustapha et al, 1997;Chowdhury et al, 1998;European Commission, 1999;Lee et al, 2001;IAEA, 2003;Kumar et al, 2003;Arafa, 2004;Ahmed, 2005;ICRP, 2005;Al-Saleh and Al-Berzan, 2007;El-Taher et al, 2007;Lu et al, 2007;Ghosh et al, 2008;Kitto et al, 2008;Mujahid et al, 2008). Although the activity concentrations for the majority of those samples were below health-based screening levels and exposure guidelines used in the US, Europe, and elsewhere, a portion of the granite samples had a radiation hazard index that exceeded the European Commission (EC) screening value for limited use as superficial building materials (external dose of 0.3 mSv/a) (European Commission, 1999).…”