S/N

²²⁶Ra (Bq∙kg⁻¹)

²³²Th (Bq∙kg⁻¹)

⁴⁰K (Bq∙kg⁻¹)

1

59.3 ± 5.9

39.3 ± 6.6

331 ± 18

2

38.9 ± 4.2

41.7 ± 7.0

293 ± 16

3

52.4 ± 5.3

42.1 ± 7.1

299 ± 16

4

47.3 ± 4.9

41.0 ± 6.1

329 ± 18

5

40.6 ± 4.3

44.8 ± 7.5

321 ± 17

6

46.5 ± 4.8

61.0 ± 10.0

340 ± 18

7

21.5 ± 2.8

57.1 ± 9.4

316 ± 17

8

35.7 ± 3.9

33.6 ± 5.8

300 ± 16

9

42.5 ± 4.5

43.0 ± 7.2

313 ± 17

10

39.2 ± 4.2

40.6 ± 6.8

294 ± 16

11

47.6 ± 4.9

58.0 ± 9.5

320 ± 17

12

26.7 ± 3.2

48.7 ± 8.1

332 ± 18

13

44.4 ± 4.6

49.1 ± 8.1

318 ± 17

14

23.8 ± 3.0

42.3 ± 7.1

350 ± 19

15

27.5 ± 3.2

41.5 ± 7.0

309 ± 17

16

49.4 ± 5.0

54.5 ± 5.0

310 ± 17

17

41.6 ± 4.4

56.3 ± 9.2

356 ± 19

18

65.7 ± 6.4

62.9 ± 10.3

321 ± 17

19

28.5 ± 3.3

63.7 ± 10.4

330 ± 18

20

37.5 ± 4.0

61.1 ± 10.0

328 ± 18

Mean ± Std Dev

40.8 ± 11.6

49.1 ± 9.3

321 ± 17