Elements concentration (μg/g)

Ca

Cu

Fe

Pb

Zn

Cr

Cd

Mg

Ni

Average

1501

5.8

55.8

10.2

22.2

<0.1

<0.1

186.5

<0.04

Maximum

4970

58.8

667.8

14.3

92.0

<0.1

<0.1

236.8

<0.04

Minimum

97.1

0.29

0.1

7.1

0.17

<0.1

<0.1

18.1

<0.04