Table 1.

Distribution of lymphocyte (%) across the four components in children and adults (ICRP Publication 89⁽⁷⁾).

Age	Mass (g)	Distribution of lymphocytes (%)
		Red bone marrow	Blood	Lymphatic organsa	Outside hematopoietic tissues
Newborn	150	5.0	0.3	16.0	78.7
1 year	650	3.0	0.2	12.0	84.8
5 years	650	3.0	0.2	12.0	84.8
10 years	900	4.5	0.2	9.5	85.8
15 years	1250	6.0	0.2	7.5	86.3
Adult female	1500	7.0	0.2	7.0	85.8
Adult male	1300	7.0	0.2	7.0	85.8

^aLymphatic organs include spleen, lymph node, thymus and small intestine.