## 4 Conclusions  
This study clearly demonstrates that heavy metals accumulated in the five vegetables that were planted in the contaminated soils, especially so for water spinach. Meanwhile, Cd accumulation of all vegetables planted in the contaminated soils was greater than Cu accumulation. In Cd-contaminated soils, there was a significant effect on the growth and yield of potato and sweet potato, and there was also a significant effect on the growth and yield of sweet potato in the Cu-contaminated soils. In addition, our findings also demonstrated that, when the concentration of vitamins C and E significantly increased in water spinach and sweet potato leaves while it was planted in heavy metal-contaminated soils, in contrast, it significantly decreased in sweet potato and tomato. The non-carcinogenic HI of Cd exposure from water spinach and sweet potato were \(>\)1, whereas those for Cu were \(<\)1. The current study suggests that vegetable consumers may experience health risks, and that children are the most vulnerable to the adverse effects of heavy metal ingestion. Meanwhile, the low accumulation rate that was seen in sweet potato leaf, potato, and tomato indicated their suitability for planting in suspected contaminated soil, such as at farms nearby metal industries, in replacement of other leafy vegetables with high accumulated character for metal contaminants, such as water spinach. The following are available online at [[https://www.mdpi.com/article/10.3390/app11093761/s1](https://www.mdpi.com/article/10.3390/app11093761/s1)]([https://www.mdpi.com/article/10.3390/app11093761/s1](https://www.mdpi.com/article/10.3390/app11093761/s1)), Table S1: Demographic data of soil property of experiment group with Cd and Cu contaminants, Tables S2-1 to S2-10: Spearman correlation (r) between metal levels in soil and different vegetables, and Vitamins in different vegetables. Methodology, W.-H.C.; formal analysis, H.-Y.L. ; resources, W.-L.H. and S.-F.C. ; writing--original draft preparation, H.-Y.L. and H.-L.C. ; writing--review and editing, H.-L.C. ; funding acquisition, H.-L.C. All authors have read and agreed to the published version of the manuscript. This research was funded by National Cheng Kung University (D108-F2523). **Institutional Review Board Statement:** Not applicable. **Informed Consent Statement:** Not applicable. **Conflicts of Interest:** The authors declare no conflict of interest. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Age** & **Water Spinach** & **Sweet Potato Leaf** & **Potato** & **Sweet Potato** & **Tomato** & **HI** \\ \hline
0–3 & 0.03–0.11 & 0.01–0.04 & 0.04–0.13 & 0.11–0.34 & 0.04–0.12 & 0.26–0.56 \\
3–6 & 0.03–0.10 & 0.01–0.04 & 0.03–0.08 & 0.02–0.06 & 0.05–0.15 & 0.16–0.31 \\
6–12 & 0.04–0.14 & 0.02–0.06 & 0.09–0.28 & 0.03–0.09 & 0.03–0.11 & 0.23–0.52 \\
12–16 & 0.02–0.07 & 0.01–0.03 & 0.06–0.19 & 0.01–0.03 & 0.02–0.08 & 0.14–0.30 \\
16–18 & 0.03–0.09 & 0.01–0.04 & 0.04–0.13 & 0.01–0.03 & 0.02–0.06 & 0.13–0.26 \\
19–65 & 0.06–0.17 & 0.02–0.07 & 0.02–0.07 & 0.01–0.04 & 0.04–0.11 & 0.17–0.33 \\ \(>\)65 & 0.08–0.23 & 0.03–0.09 & 0.03–0.09 & 0.02–0.06 & 0.03–0.08 & 0.21–0.40 \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Hazard index of Cu intake by age groups. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Age** & **Water Spinach** & **Sweet Potato Leaf** & **Potato** & **Sweet Potato** & **Tomato** & **HI** \\ \hline
0–3 & 1.40–4.36 & 0.09–0.28 & 0.09–0.29 & 2.70–8.69 & 0.15–0.45 & 4.80–11.6 \\
3–6 & 1.42–4.19 & 0.09–0.27 & 0.06–0.19 & 0.47–1.41 & 0.19–0.57 & 2.40–5.44 \\
6–12 & 1.81–5.82 & 0.12–0.38 & 0.19–0.65 & 0.68–2.26 & 0.12–0.39 & 3.18–7.77 \\
12–16 & 0.87–2.75 & 0.06–0.18 & 0.13–0.44 & 0.25–0.82 & 0.09–0.29 & 1.52–3.65 \\
16–18 & 1.27–3.96 & 0.08–0.26 & 0.09–0.29 & 0.27–0.85 & 0.07–0.21 & 1.88–4.74 \\
19–65 & 2.38–7.02 & 0.15–0.45 & 0.05–0.15 & 0.36–1.08 & 0.14–0.42 & 3.20–7.97 \\ \(>\)65 & 3.27–9.63 & 0.21–0.62 & 0.06–0.19 & 0.52–1.54 & 0.10–0.31 & 4.36–10.8 \\ \hline \hline \end{tabular}
\end{table}