Juglone in harvested nettle roots a concern?

We have a thick stand of healthy nettles growing in proximity to a couple mature walnut trees. The trees are about 50 feet apart, and the nettle patch is not exactly between them, but off to the side.

I wanted to harvest the nettle roots and sell cleaned/dried roots for a little side income but I am wondering about the likelihood of toxins being passed to the end users of the nettle roots. The research I've done so far indicates there is no reason to be concerned. The roots I have harvested so far, about 10 ft. away from one of the trees, were not near any tree roots that I could see. But there is some amount of windfall of leaves and nuts on the nettle patch, which concerns me more than the possibility of root-to-root contact.

Anyone have some hard info on this?