## 3 Results and Discussions
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Elements** & **DIPTE** & **R\({}_{\text{fd}}\)** & **HRI** \\ \hline As & \(6\times 10^{-8}\) & \(3\times 10^{-4}\) & \(2\times 10^{-4}\) \\ Cd & \(4\times 10^{-6}\) & \(5\times 10^{-3}\) & \(8\times 10^{-4}\) \\ Co & \(2\times 10^{-6}\) & \(5\times 10^{-3}\) & \(5\times 10^{-4}\) \\ Cr & \(1\times 10^{-5}\) & \(2\times 10^{-0}\) & \(1\times 10^{-5}\) \\ Cu & \(3\times 10^{-4}\) & \(4\times 10^{-2}\) & \(7\times 10^{-3}\) \\ Ni & \(2\times 10^{-4}\) & \(2\times 10^{-2}\) & \(1\times 10^{-2}\) \\ Pb & \(2\times 10^{-5}\) & \(4\times 10^{-3}\) & \(4\times 10^{-3}\) \\ Sb & \(6\times 10^{-7}\) & \(4\times 10^{-3}\) & \(1\times 10^{-4}\) \\ Tl & \(6\times 10^{-6}\) & \(3\times 10^{-4}\) & \(2\times 10^{-4}\) \\ U & \(4\times 10^{-6}\) & \(3\times 10^{-3}\) & \(1\times 10^{-3}\) \\ V & \(4\times 10^{-6}\) & \(9\times 10^{-3}\) & \(5\times 10^{-4}\) \\ Zn & \(1\times 10^{-3}\) & \(3\times 10^{-1}\) & \(5\times 10^{-3}\) \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Values of the Daily Intake (DIPTE, mg/kg/day), reference dose (R\({}_{\text{fd}}\), mg/kg/day), and Health Risk Index (HRI) for each PTE in bulbs of elephant garlic from the Valdichiana area. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Elements** & \multicolumn{3}{c}{**Valdichiana Soils**} & **Soil Background** & **Soil Background** \\ \cline{2-5}  & **Min** & **Max** & **Mean \(\pm\) std. dev.** & **Soil** & **Riley** \\ \hline As & 5.4 & 24.2 & \(10.9\pm 6.8\) & 18.0 & 41 \\ Cd & 0.12 & 0.23 & \(0.18\pm 0.04\) & 0.87 & 0.44 \\ Co & 9.0 & 25.7 & \(15.8\pm 5.5\) & 17.3 & 14 \\ Cr & 46.3 & 124.8 & \(87.6\pm 29.8\) & 132.5 & 95 \\ Cu & 29.8 & 90.1 & \(50.2\pm 18.8\) & 36.3 & 24 \\ Ni & 39.0 & 92.5 & \(66.8\pm 17.1\) & 74.6 & 50 \\ Pb & 20.8 & 51.4 & \(29.2\pm 9.7\) & 32.0 & 26 \\ Sb & 0.49 & 1.07 & \(0.66\pm 0.21\) & 2.1 & **0.77** \\ Tl & 0.26 & 0.63 & \(0.44\pm 0.13\) & 0.34 & **0.83** \\ U & 1.3 & 2.04 & \(1.68\pm 0.26\) & 2.4 & 3.17 \\ V & 62.6 & 110.7 & \(81.7\pm 16.2\) & 96.5 & 76 \\ Zn & 55.0 & 120.5 & \(78.5\pm 18.9\) & 116.7 & 68 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Concentrations (mg/kg dw) of PTEs in AdV cultivation soils in the Valdichiana area, along with their background levels in soils of Southern Tuscany [22,23] and Italy [24]. Values in bold were calculated from the concentrations of PTEs in 51 surface soil samples collected in Italy [45]. clearly indicated the absence of soil contamination by PTEs as all values were below the threshold of 0 (Figure 1b) [47]. Using as reference the PTE background levels in soils of Italy (Figure 1a,b), several PTEs such as Co, Cu, Ni, Pb, V, Zn, showed CF average values in the range 1-2 in the AdV cultivation soils in the Valdichiana area, indicating a moderate contamination [46]. Conversely, the results of Igo confirmed the absence of soil contamination for all PTEs (Igo\({}_{\text{geo}}\) < 0; absent contamination), except for Cu which showed an average value of 0.4, indicating a low to moderate contamination [47]. The above-reported results for the CF and Igo indices suggested that Cu is the only PTE for which there is some concern about its levels in agricultural soils of the Valdichiana area. On the other hand, it is well-known that Cu is present in somewhat high concentrations in agricultural soils of Tuscany, being Cu-based products such as the Bordeaux mixture, widely used in agriculture [48; 49]. According to soil concentrations of PTEs, the Ecological Risk Factor (ERF) and the Potential Ecological Risk Index (PERI) for the Valdichiana soils had average values below their respective lowest thresholds of 40 and 65 (Table 2; Figure 2), suggesting therefore a very low ecological risk [28].