Identifying age-specific windows of vulnerability: a lifetime dose assessment of Ra-226 in drinking water

. In contrast to Ra-228, Ra-226 did not produce a comparable adolescent dose peak, reflecting faster dose saturation following intake and limited long-term contribution from short-lived progeny. These results demonstrate that adult-only screening does not capture the timing and distribution of Ra-226 ingestion dose and that age-dependent lifetime modelling provides a more realistic basis for assessing chronic exposure from drinking water.