In this context the dose contributions of thoron (
220
Rn) and its
decay products can exceed the corresponding radon (
222
Rn)
values, as in the indoor environment thoron is considered more
likely to originate from exhalation of building materials rather
than from soils due to its shorter half-life. Consequently indoor
radon and thoron concentrations should be monitored and building materials should be classified on the basis of their radon and
thoron exhalation rates which can then be correlated with their
activity concentration index (I) value, based on
232
Th,
226
Ra and
40
K concentrations.
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journal homepage: www.elsevier.com/locate/apradiso
Applied Radiation and Isotopes
http://dx.doi.org/10.1016/j.apradiso.2014.10.007
0969-8043/&2014 Elsevier Ltd. All rights reserved