Izotope

²³⁸U

²³⁴U

²³²Th

²³⁰Th

²²⁸Th

²²⁶Ra

²¹⁰Pb

²¹⁰Po

Annual absorption

6.12

8.37

1.09

1.74

4.92

18.6

43.4

44.0