That would be "HOT DIPPED" hardware cloth which will contain some lead since it is used as a flow agent for the zinc galvanization process.
The amount of lead can vary from manufacturer to manufacturer, if it was going to be sold in California there would be a carcinogenic warning as well.
Lead is easily taken into good soils via bacterial enzymatic action.
You can tell if the mesh was hot dipped by visual inspection, there will be rather obvious
drip marks (it will look rough) at the weave intersections.
If your soil is more acidic than 6.8, there could be some leaching into the soil and it would then be picked up by the roots and move into the plant.
There are Electoplated hardware cloths out there that do not contain any lead.
Redhawk
