The element lead is rather harmless itself. I get a kick out of reading something like "Dust from lead wheelweights contaminates soils near roads, so don't get your herbs near roads". It isn't the dust from wheelweights, it years and years of tetra-ethyl lead deposited along the roadways. I had an old friend who was a mechanic for nigh 40 years. He washed his hands in leaded gasoline several times a day. Such lead builds up in the heart and other organs. It was his heart finally got him at 82, with a little help from doctors who opened him up when he had the flu. I can't see much of a connection between lead levels and lyme, other than the fact that high lead levels may hamper the immune system.
I just googled "lyme disease lead poisoning" and got a bunch of hits, but not sure what they are. Will keep an eye out, tho -- thanks for the comment. Let us know what you find out.