Trace Elements (ppm)

Mean

Range

MRL (ppm)¹

Ba

20

8 - 38

0.2

Co

76

65 - 88

0.01

Cr

2486

1772 - 3290

0.005

Cu

26

3 - 70

0.01

Ni

1246

833 - 1568

2 * 10⁻⁷

Pb

0.72

0.2 - 2

No safe threshold

Rb

2

0.3 - 10

-

Sr

12

5 - 35

2

V

48

33 - 65

0.01

Zn

16

6 - 34

0.3