年份

²³⁸U

²³²Th

²²⁶Ra

⁴⁰K

⁹⁰Sr

¹³⁷Cs

2012

26.7

61.3

40.1

631

0.27

0.52

2013

39.6

48.9

30.5

476

0.58

<0.32

2014

<22.8

49.5

30.2

524

0.55

<0.32

2015

34.2

43.7

33.3

554

-

<0.32

2017

39.0

47.0

29.0

494

-

<0.32

2018

30.0

41.0

24.0

607

-

0.70

2019

43.0

51.0

31.0

500

1.0

<0.32

2020

33.0

52.0

36.0

524

-

<0.32

2021

27.0

55.0

36.0

576

-

<0.32

范围

<22.8~43.0

43.7~61.3

24.0~40.1

476~631

0.27~1.0

<0.32~0.70

均值

34.1 ± 6.06

49.9 ± 6.0

32.2 ± 4.7

543 ± 53

0.6 ± 0.3

-