Table 2.

Significance test (ANOVA) of subtracted results along with the gradient.

Heavy metal	Urban(n* = 5)	Suburban (n = 5)	Rural (n = 4)
Pb (mg/kg)	13.05	1.91	−1.74
Zn (mg/kg)	55.44	−2.72	11.1
Cr (mg/kg)	15.06	−1.75	−3.1
Hg (mg/kg)	0.087	−0.041	0.051
Cu (mg/kg)	6.68	−0.61	−4.39

^*n is the number of the sample.