Income Group

Sample No.

Heavy metal (mg∙kg⁻¹)

As

Pb

Cd

Cr

Cu

Zn

Hg

Lower

1

0.09

4.58

0.03

1.91

0.004

15.90

0.12

2

1.17

7.90

0.09

2.98

0.001

21.23

0.14

Lower middle

1

1.98

11.09

0.04

4.78

0.004

32.90

0.21

2

4.58

16.73

0.93

15.98

0.007

34.85

0.92

Middle

1

8.90

16.73

3.23

56.83

0.007

43.11

0.12

2

11.46

14.79

2.62

54.71

0.02

51.11

0.13

High

1

16.78

16.77

3.33

61.67

0.06

67.55

0.22

2

21.34

15.96

4.24

74.19

0.09

65.46

0.01