Pb

Cd

As

Zn

Ni

Cu

Hg

Pb

1

Cd

0.402*

1

As

−0.096

0.476**

1

Zn

0.619**

0.709**

0.330

1

Ni

−0.038

0.395*

0.278

0.319

1

Cu

0.139

0.200

0.256

0.158

0.457**

1

Hg

−0.029

0.131

0.511**

0.353*

−0.110

0.062

1