Description

Rn-222 is the daughter of Ra-226 and is a noble gas with a half-life of about 4 days; it decays through a series of very short-lived radionuclides (half-life 27 minutes or less) to Pb-210 (half-life 21 years). In the biosphere, if Ra-226 is present in soil, then a fraction of the Rn-222 produced (a few to a few tens of %) would escape to the atmosphere and be rapidly dispersed. However, there is a potential for significant doses from Rn-222 and its short-lived daughters in conditions of limited air circulation. In buildings, Rn-222 emanating from Ra-226 in underlying soil and rocks, or in building materials, may accumulate.

OPA Category

Category as used in the OPA assessment

Biosphere

OPA Number

Number as used in the OPA assessment

3.27

NEA V1 IFEP Reference(s)

Related IFEPs from the NEA V1 IFEP list from 1999

3.3.08, 2.4.07, 3.2.10