## 2 Results
### Concentrations at the Pods Stage  
The results indicate that for common bean, roots accumulate more metals than shoots and pod for Pb; whereas for Cu, shoots accumulate more metals than roots and pods; and for Cd, pods accumulate more metals than roots and shoots. For faba bean, in the case of Pb and Cd, roots recorded the highest concentration; while copper concentrations are the highest in the pods and lowest in the shoots (Table 7). The BAF is the highest for Pb for both the varieties of plants. Pb tends to concentrate in the roots, leading to a lower TF value, for both beans and faba beans, be it with respect to the shoots or the pods. The ratios TF\({}_{\text{shoots}}\) and TF\({}_{\text{pods}}\) are the highest for Cd in the case of common bean (values over 3). In the case of faba bean, Cu has the highest TF when it comes to pods, while Cd takes the first position when it comes to shoots (Table 8). Common bean and faba bean are thus hyper-accumulators for Cd and Cu, respectively.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Species** & **Treatment** & **BAF** & **TF\({}_{\text{S}}\)** & **TF\({}_{\text{H}}\)** \\ \hline \multirow{3}{*}{Common bean} & Lead & 2.42 \({}^{\text{a}}\)\(\pm\) 0.35 & 0.80 \({}^{\text{a}}\)\(\pm\) 0.003 & 0.05 \({}^{\text{c}}\)\(\pm\) 0.0005 \\  & Copper & 0.69 \({}^{\text{c}}\)\(\pm\) 0.05 & 0.32 \({}^{\text{c}}\)\(\pm\) 0.002 & 0.18 \({}^{\text{a}}\)\(\pm\) 0.004 \\  & Cadmium & 1.75 \({}^{\text{b}}\)\(\pm\) 0.004 & 0.52 \({}^{\text{b}}\)\(\pm\) 0.006 & 0.09 \({}^{\text{b}}\)\(\pm\) 0.0008 \\ \hline \multirow{3}{*}{Faba bean} & Lead & 1.19 \({}^{\text{a}}\)\(\pm\) 0.01 & 0.68 \({}^{\text{c}}\)\(\pm\) 0.007 & 0.82 \({}^{\text{b}}\)\(\pm\) 0.07 \\  & Copper & 1.08 \({}^{\text{a}}\)\(\pm\) 0.03 & 1.38 \({}^{\text{a}}\)\(\pm\) 0.18 & 1.48 \({}^{\text{a}}\)\(\pm\) 0.38 \\ \cline{1-1}  & Cadmium & 0.21 \({}^{\text{b}}\)\(\pm\) 0.005 & 0.94 \({}^{\text{b}}\)\(\pm\) 0.10 & 0.63 \({}^{\text{c}}\)\(\pm\) 0.05 \\ \hline \hline \end{tabular}
\end{table}
Table 6: Bafs and TFs for bean and faba bean plants at flowering stage.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Species** & **Treatment** & **RC (ppm)** & **SC (ppm)** & **FIC (ppm)** \\ \hline \multirow{4}{*}{Common bean} & Control & 1.31 \({}^{\text{d}}\)\(\pm\) 0.20 & 0.05 \({}^{\text{d}}\)\(\pm\) 0.0003 & 0.008 \({}^{\text{c}}\)\(\pm\) 0.0004 \\  & Lead & 20.73 \({}^{\text{a}}\)\(\pm\) 1.45 & 16.04 \({}^{\text{a}}\)\(\pm\) 0.10 & 1.00 \({}^{\text{b}}\)\(\pm\) 0.006 \\  & Copper & 13.13 \({}^{\text{b}}\)\(\pm\) 0.88 & 4.35 \({}^{\text{c}}\)\(\pm\) 0.45 & 2.51 \({}^{\text{a}}\)\(\pm\) 0.15 \\  & Cadmium & 9.96 \({}^{\text{c}}\)\(\pm\) 0.65 & 5.22 \({}^{\text{b}}\)\(\pm\) 0.55 & 1.01 \({}^{\text{b}}\)\(\pm\) 0.007 \\ \hline \multirow{4}{*}{Faba bean} & Control & 1.31 \({}^{\text{c}}\)\(\pm\) 0.008 & 0.05 \({}^{\text{d}}\)\(\pm\) 0.0004 & 0.008 \({}^{\text{d}}\)\(\pm\) 0.0003 \\  & Lead & 9.79 \({}^{\text{b}}\)\(\pm\) 0.70 & 6.72 \({}^{\text{b}}\)\(\pm\) 0.25 & 8.05 \({}^{\text{b}}\)\(\pm\) 0.32 \\  & Copper & 13.09 \({}^{\text{a}}\)\(\pm\) 0.91 & 17.99 \({}^{\text{a}}\)\(\pm\) 1.06 & 19.38 \({}^{\text{a}}\)\(\pm\) 1.05 \\  & Cadmium & 1.32 \({}^{\text{c}}\)\(\pm\) 0.005 & 0.94 \({}^{\text{c}}\)\(\pm\) 0.004 & 0.61 \({}^{\text{c}}\)\(\pm\) 0.0005 \\ \hline \hline \end{tabular}
\end{table}
Table 5: The HM concentrations in roots, shoots and flowers in common bean and faba bean at the flowering stage.