## 3 Results and Discussions
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Elements**} & \multicolumn{3}{c}{**Valdichiana Elephant Garlic (AdV)**} & \multirow{2}{*}{
\begin{tabular}{c} **Elephant Garlic from** \\ **Uncontaminated Soils** \\ \end{tabular} } \\ \cline{2-2} \cline{4-4}  & **Min** & **Max** & **Mean \(\pm\) std.** & **Uephant Garlic from** \\ \hline As & \textless{}0.001 & \textless{}0.001 & – & 0.07 \\ Cd & \textless{}0.001 & 0.29 & 0.07 \(\pm\) 0.09 & 0.02 \\ Co & 0.02 & 0.07 & 0.04 \(\pm\) 0.02 & — \\ Cr & 0.01 & 0.46 & 0.17 \(\pm\) 0.13 & 2.2 \\ Cu & 2.41 & 6.62 & 4.34 \(\pm\) 1.18 & 1.1–10 \\ Ni & 0.72 & 8.76 & 3.65 \(\pm\) 2.30 & 0.2 \\ Pb & 0.22 & 0.41 & 0.27 \(\pm\) 0.05 & 0.1 \\ Sb & \textless{}0.001 & 0.06 & 0.01 \(\pm\) 0.01 & – \\ Tl & \textless{}0.001 & \textless{}0.001 & – & – \\ U & 0.06 & 0.09 & 0.07 \(\pm\) 0.01 & – \\ V & 0.04 & 0.12 & 0.07 \(\pm\) 0.02 & – \\ Zn & 12.94 & 44.20 & 23.92 \(\pm\) 8.18 & 6.5–40 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Concentrations (mg/kg dw) of PTEs in bulbs of elephant garlic from the Valdichiana area (AdV). For the calculation of mean and standard deviation of Cd and Sb concentrations, the values \textless{}LOD (0.001 mg/kg) were considered equal to the limit of detection. For comparison, concentrations of PTEs in bulbs of elephant garlic grown in uncontaminated soils [11; 29; 30] are also reported. In more detail, DIPTE values for PTEs showed the following order (mg/kg/day): Zn \(>\) Cu \(>\) Ni \(>\) Pb \(>\) Cr \(>\) U \(>\) V \(>\) Cd \(>\) Co \(>\) Sb, from the most to the less relevant element from a biological point of view. Moreover, when DIPTE values are compared with their respective reference dose (R\({}_{\text{fd}}\); Table 4), the consumption of AdV closes resulted in an uptake of PTEs several orders of magnitude lower than the maximal oral reference dose which guarantees acceptable human exposure limits [43]. In addition, the HRI values of all the investigated PTEs (Table 4) were at least 100 times lower than the threshold of 1 (HRI \(<<\) 1), indicative of no risk for human health as well as the complete improbability to develop carcinogenic effects [44]. This is further confirmed by the fact that even using maximum concentrations, HRI values were all \(>\)35 times below 1. For comparison, garlic plants cultivated using questionable techniques or irrigated with wastewaters showed HRI values several times beyond the threshold of 1 (HRI \(>\) 1), indicating possible adverse effects for human health [17]. Concentrations of PTEs in AdV cultivation soils in the Valdichiana area (Table 5) are overall comparable with the respective background level in soils of Southern Tuscany [22,23] and Italy [24]. The Contamination Factor (CF) of PTEs calculated using their background levels in soils from Southern Tuscany (Figure 1a) indicated the absence of contamination or low contamination for most of the analyzed PTEs, as CF values were normally \(<\)1 in the investigated AdV cultivation soils [46]. Copper and Tl were the only exceptions since both elements frequently showed CF values between 1 and 3 (on average 1.5 and 1.2, respectively), suggesting a moderate soil contamination. The geo-accumulation index (I\({}_{\text{geo}}\))