Size (Inch)

Mean Activity Concentrations (Bq·kg⁻¹)

²³⁸U

²³²Th

⁴⁰K

$\frac{3}{4}$ inch

12.64 ± 1.89

16.93 ± 2.46

266.19 ± 35.53

$\frac{1}{2}$ inch

8.76 ± 1.28

13.69 ± 1.95

151.85 ± 25.09

Stone-dust

5.10 ± 0.77

8.97 ± 1.37

164.27 ± 23.51