Table 1 Descriptive statistics of geochemical parameters of surface soil (0–20 cm) in the study area.

Cr (mg/kg)

11.73

77.29

973

103

126

122

95.9

Ni (mg/kg)

6.79

45.40

222

49.03

27.16

55.40

39.1

Cu (mg/kg)

5.51

33.80

446

46.77

59.27

126

32

Zn (mg/kg)

61.17

323

4004

617

760

123

99.5

Pb (mg/kg)

35.93

154

1891

309

364

117

35.2

Cd (mg/kg)

0.35

1.93

29.64

3.51

4.38

124

0.66

As (mg/kg)

10.41

35.26

160

41.65

25.07

60.20

20

Hg (mg/kg)

0.10

0.41

1.41

0.50

0.31

61.30

0.11

SiO₂ (%)

5.88

56.17

72.72

52.89

15.43

29.20

-

Al₂O₃ (%)

1.94

15.81

24.67

15.35

4.80

31.30

-

TFe₂O₃ (%)

0.98

6.66

17.19

7.06

2.93

41.50

-

MgO (%)

0.72

1.44

19.35

3.21

4.44

138

-

CaO (%)

0.10

0.75

26.8

3.67

6.67

181

-

Na₂O (%)

0.03

0.13

0.41

0.14

0.07

46.4

-

K₂O (%)

0.29

2.24

5.95

2.33

1.25

53.50

-

pH ^a

5.23

6.91

7.60

6.76

0.60

8.93

-

TOC (%)

0.09

2.39

6.20

2.45

1.43

58.50

-

CEC [cmol (+)/kg]

0.79

6.14

13.39

6.35

2.88

45.29

-

Texture (%)

Sand

0.18

8.16

89.48

17.83

24.47

137

-

Silt

0.68

69.78

95.40

61.60

23.13

37.60

-

Clay

2.74

17.51

65.39

20.57

13.60

66.10

-