Element

Contents in sample ( mg. kg⁻¹)

Surface 1

Surface 2

Surface 3

Surface 4

Surface 5

Surface 6

As

3.1

10.5

5.3

14.1

4.1

1.9

Be

1.53

1.32

0.75

1.65

0.95

0.11

Cd

0.64

0.43

0.30

0.83

0.43

0.08

Co

14.9

16.1

19.1

21.3

9.9

4.2

Cr

44.5

48.9

21.5

55.4

36.2

8.1

Cu

33.8

44.2

26.1

53.2

32.8

4.6

Hg

-

-

-

-

-

-

Mo

2.66

3.01

1.98

3.25

1.66

0.18

Ni

31.4

28.6

16.4

33.6

18.3

6.25

Pb

28.6

35.2

22.5

46.8

32.8

9.3

V

23.9

28.6

9.7

31.5

18.6

8.5

Zn

63.2

88.5

23.6

86.2

24.7

11.2