*2.5. Statistical Analysis*

Statistical analysis was performed by using the statistical software SPSS® 20.0 (New York, NY, USA). Analysis of variance (ANOVA) was used to assess the influence of district and soil use on the PTE concentrations. The Student's t-test was performed to compare pseudo-total and Mehlich-3 extractable metals in soils with and without gleyic properties and in surface and subsurface horizons. Principal component analysis (PCA) was applied to the pseudo-total data set for identifying associations among metals. Varimax was used as the rotation method in the PCA. The Kolmogorov–Smirnov (K–S) test was applied to check the normal distribution of data. Correlation coefficients were determined to complete and support the results obtained by factorial analysis.
