Sample

Ash

N

Activity of radionuclide (Bq/kg)

K⁴⁰

Ra²²⁶

Th²³²

Po²¹⁰

Witbank (Present Study)

Fuel (Coal)

25%

9

88 ± 6

21 ± 1

22 ± 4

46 ± 1

Fly ash

9

348 ± 8

80± 3

88 ± 6

193± 8

Bottom ash

9

334 ± 8

63± 3

84 ± 6

41 ± 7

Waterberg (Present Study)

Fuel (Coal)

33%

9

91 ± 3

52 ± 5

21 ± 1

70 ± 5

Fly ash

9

319 ± 4

166 ± 8

63 ± 6

280 ± 8

Bottom ash

9

302 ± 5

150 ± 13

82 ± 8

3 ± 1

Sasolburg (Present Study)

Fuel (Coal)

41%

9

110 ± 4

24 ± 5

19 ± 3

83 ± 3

Fly ash

9

286 ± 4

65± 6

45 ± 6

265 ± 13

Bottom ash

9

242 ± 13

51± 6

44 ± 2

2 ± 1

Spain: Teruel UPT [25]

Fuel (Coal)

22%

2

66 ± 15

54 ± 3

21 ± 3

65 ± 11

Fly ash

2

306 ± 13

191 ± 9

74 ± 3

257 ± 30

Bottom ash

2

235 ± 11

149 ± 6

66 ± 3

57 ± 7

Spain: Litoral UPT [25]

Fuel (Coal)

16%

2

70 ± 16

15 ± 3

13 ± 3

33 ± 4

Fly ash

2

338 ± 16

107± 4

87 ± 4

300 ± 40

Bottom ash

2

278 ± 16

81 ± 4

64 ± 4

7 ± 1

Spain: Compostilla II [24]

Fuel (Coal)

37%

2

334 ± 13

34 ± 3

33 ± 3

118 ± 40

Fly ash

2

1109 ± 49

94 ± 4

93 ± 4

416 ± 57

Bottom ash

2

1077 ± 48

86 ± 2

89 ± 3

24 ± 12

Spain: Teruel [24]

Fuel (Coal)

28%

2

77 ± 32

56 ± 5

21 ± 2

65 ± 11

Fly ash

2

310 ± 14

190 ± 2

74 ± 2

257 ±30

Bottom ash

2

238 ± 13

149 ± 5

66 ± 3

57 ± 7

Spain: Litoral [24]

Fuel (Coal)

15%

4

62 ± 30

18 ± 4

20 ± 6

47 ± 20

Fly ash

4

250 ± 144

158 ± 48

154 ± 53

505 ± 321

Bottom ash

4

224 ± 105

144 ± 55

138 ± 61

9 ± 4