## 3 Results and Discussion
### Pedological and Chemical Properties of the Homogeneous Zones (HZs)
Therefore, considering that a decrease of radionuclide activity is generally measured in correspondence of limestone, carbonic layers and stoniness, the presence of C layers, like those observed in P4 of HZ3 and P5 of HZ4a, could be related to the low values (71-77 nGy/h) of \(\gamma\)-rays dose rates in HZ3 (the lowest of the whole site) as well as those measured in proximity to P5 (86 nGy/h) in HZ4a. This would be in addition to the effects of the waste disposal. On the contrary, in area P7, where no stones were identified but evidence of volcanic soil was found, higher \(\gamma\)-rays dose rate values (110 nGy/h) were measured (Figure 5B). These results were consistent with data reported from Tuscany for soils formed by different parent materials and characterized by different stoniness levels. Soil reaction was generally neutral to slightly alkaline (from 6.7 to 8.2), while higher values (pH = 8.3-8.4) were measured for the massive topsoil and C horizon of P4. However, P1 and P4 showed the highest average pH values (7.9), as well as the highest total carbonates content (4.5-8.5%). P1 showed the highest electrical conductivity values. Soil organic C content had a general decreasing trend with depth, but when buried A horizons (Ab) were encountered, increasing content was measured. Correlation between CEC and OC was not strongly significant (0.419 *) because of the highly anthropized context. On the contrary, when the regression was calculated between CEC and OC, taking into account only the buried (Ab and Bwb) yellow-red (YR) and anodic-like soils, a very high coefficient of determination was found (\(r^{2}\) = 0.88, respectively), suggesting the major role of organic matter in soil charge for these natural soils. This result was consistent with the highest values of CEC (from 31.2 to 53.0 cmol (+)/kg) measured for these buried soils. It is known that Andosols and anodic soils frequently show high values of CEC when measured with the BaCl\({}_{2}\) (pH 8.2) and triethanolamine methods, due to their peculiar highly variable and pH-dependent cation exchange capacity (CEC increasing with pH). This is caused by the presence of variable charge minerals, such as allophane and imogolite [72], and organic matter. In situ measurements of PTEs are reported in Table 4. All the topsoils (from the surface to 20-35 cm) except P7 were widely contaminated by Pb, from 1 to 10 times the CSC3; however, for P1, contamination reached 100 cm of depth (Table 4A). Cadmium was found to exceed CSC3 for the same horizons contaminated by Pb. Then, among the possible interelement interferences, the Olympus factory indicated that high levels of Pb could interfere with low levels of As. This element content, measured by XRF, was recalculated considering aqua regia (AR)--ICP-MS measurements [22] below 200 mg/kg, the maximum value reached by As in the profiles (Table 4A,B). Per the results, surface horizons were generally the most contaminated by As: in P3 and P4, As content exceeded CSC2 in depths ranging from the surface to 25 cm, while in all the other profiles, As exceeded CSC3 in the same range, but P1 showed As contamination exceeding CSC1 up to 150 cm (Table 4A,B). For Cu and Zn, several topsoils were found to exceed CSC1 and CSC2, while no CSC exceeding value was found for Cr. P7 was the only profile that did not exceed CSC3 for Pb content (Table 4B). It also showed the lowest As and Cd content (below CSC1) found among all the analyzed soil profiles. Significant correlations between PTE and chemical-physical soil properties were found between OC and Cu (0.475 **), Pb (0.446 **) and Zn (0.480 **), and between electrical conductivity (EC) and As (0.534 **), Cu (0.479 **), Pb (0.559 **) and Zn (0.556 **). No correlation was found between PTE and CEC. These results were consistent with findings that the most contaminated were generally the uppermost OC-enriched horizons, while the PTE correlation with EC was likely attributable to higher contents of soluble salts in these anthropogenic materials, primarily made by different types of batteries.