The concentration of metals in vegetables mainly depends on the texture of the soil or media on which they grow but this also depends on the type and nature of plant (Kabata-Pendias and Pendias, 1984).
The metal concentrations in leaves and fruit showed significant variations in the uptake by plants.
Leaves (non-edible) parts of the vegetables accumulated higher concentrations of heavy metals as compared to the edible parts.
This study also shows that there is a correlation between metals in soils
and vegetables, which transfers heavy metals into the food chain