Country

Average activity concentration (Bq/kg)

References

226Ra

232Th

40K

Yemen

45

106

1235

Present study

India

82

112

1908

[16]

Yemen

54

127

1743

[17]

Spain

84

42

1138

[18]

Saudi Arabia

75

71

987

[19]

Egypt

137

82

1082

[20]

Greek

74

85

881

[21]

Turkey

70

83

1234

[22]

Iran

74

69

1130

[23]

Italy

112

107

1063

[24]

Brazil

45

106

1320

[25]

Japan

43

72

1004

[26]

World average

50

50

500

UNSCEAR 2000 [8]