Table 5.

Pearson’s correlation matrix for the metal concentrations of sub-layer of soil.

	Urban				Suburban and rural area
Element	Pb	Zn	Cr	Hg	Pb	Zn	Cr	Hg
Pb
Zn	0.202				0.772 *
Cr	−0.590	0.011			0.885 **	0.553
Hg	0.903 **	0.057	−0.416		−0.176	0.026	−0.322
Cu	0.422	0.307	0.298	0.278	0.723	0.594	0.468	−0.010

The left lower part is the correlation coefficient; the right upper part is the significance level.

^*P < 0.05 (2-tailed);

^**P <0.01 (2-tailed).