Country

Average activity concentration (Bq/kg)

References

226Ra

232Th

40K

Yemen

14. 28

25.78

566.05

Present study

India

45.68

17.11

1535.44

[9]

Saudi Arabia (Al-Qassim)

9.3

12.3

535

[10]

Nigeria

12.12

60.117

426.51

[11]

Malaysia

57

68

427

[12]

Egypt

16.4

7.1

102

[13]

Turkey

21.0

23.5

363.5

[14]

Jordan

57.7

18.1

138.1

[15]

World average

30

35

400

[8]