*3.2. Analysis of Variance*

The analysis of variance showed that the district significantly affected the pseudo-total concentrations of As, Co, Cr, Ni, Ti, V, Hg (p < 0.001), and Mn (p < 0.05) (Table 2). On the contrary, the pseudo-total concentrations of Cd, Cu, Fe, Pb, and Zn were not significantly different among districts.

The land use did not affect significantly the pseudo-total concentrations of the elements studied.

The district of Regla had the highest concentrations of pseudo-total Co, Cr, and Ni (Figure 2). The highest concentrations of As were found in Playa and Plaza de la Revolución, while the highest concentrations of Hg were found in Playa, 10 de Octubre, and Habana Vieja. Playa had the highest concentrations of Mn, and the highest concentrations of Ti and V were found in San Miguel del Padrón and Regla.


**Table 2.** Main effects of district, soil use, and interaction district x soil use on pseudo-total PTE concentrations (significance level).

Hg **0.00** 0.13 **0.01** Bold numbers indicate significance level ≤0.05.

**Figure 2.** Distribution of pseudo-total As, Hg Co, Cr, Mn, Ni, Ti, and V in the various districts. The limits of the boxes are percentiles 25 and 75. The horizontal lines inside the boxes are the medians. The whiskers indicate the 0th and 100th percentiles, excluding outliers.
