Pearson correlation coefficients of soil heavy metals in the investigated area.

	As	Cd	Cr	Cu	Co	Pb	Zn	Mn	Fe	Ni	Al
As	1
Cd	−0.318a	1
Cr	−0.174	0.367a	1
Cu	−0.253	0.350a	0.617b	1
Co	−0.349a	0.374b	0.012	−0.028	1
Pb	−0.226	0.298a	0.600b	0.932b	−0.090	1
Zn	−0.178	0.493b	0.635b	0.874b	−0.033	0.883b	1
Mn	−0.300a	0.451b	0.172	0.015	0.642b	−0.034	0.078	1
Fe	−0.385b	−0.064	−0.020	0.137	0.628b	0.043	−0.047	0.486b	1
Ni	0.233	0.062	0.510b	0.455b	−0.108	0.488b	0.571b	−0.151	−0.152	1
Al	−0.593b	0.149	−0.132	−0.165	0.713b	−0.280	−0.280	0.539b	0.708b	−0.394b	1

^aCorrelation is significant at the 0.05 level (2-tailed).

^bCorrelation is significant at the 0.01 level (2-tailed).