We we're just looking into this as well. I was horrified to realize I could be contaminating my soil. I have not tested our soil. We had a huge problem with voles digging into our raised beds from underneath and decimating the plants so we removed all the dirt so we could line the bottom with wire but definitely didn't want to line it with wire containing lead. We ended up buying stainless steel wire mesh instead of regular galvanized chicken wire. It was more expensive but I think it was worth it.