It is possible to change relative, local concentrations of progeny in the uranium chain by chemical reactions and precipitation. Samples of soil, rock, and water have non-equilibrium concentrations of longer-lived progeny.
Progeny with half-lives on the order of minutes or less can not maintain unsupported disequilibrium in a sample.
A disequilibrium is the result of migration in an inhomogeneous context, the progeny being found in a place more or less distant from where it was produced. The migration might be the consequence of a chemical action, but this is really not necessary for Ra progeny. An efficient and well-known migrator is radon, especially in porous materials. It is able to travel over several meters. Rn222 will almost certainly travel before it decays into Po218 and then into Pb214/Po214.
A Ra-poor material close to a Ra-rich one will receive some Rn and will be enriched in Pb214/Po214.
A house built with Ra-poor material may well be contaminated by Rn coming from the subsoil, and have Pb214/Po214 deposits on the walls, in the cushions, etc...
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