” Wash DC because it has no heavy industry has poop very low in heavy metals and so makes good fertilizer”
A pretty high percentage of the DC locals I’ve spoken with appear to have eaten large amounts of lead paint chips in their youth.
Just sayin’...
1. As an older city Wash, D.C. had many homes/apartments that were coated with lead based paint. The paint lasted very well but of course the side effects of breathing paint dust or eating paint chips is well known. Renovators painted over the old paint rather than remove it.
2. I used to finance renovation loans in D.C. literally by the hundreds. One thing always happened, which is the basement was dug out, usually to put a rental unit down there. As part of that process the water lead to the house was replaced, running to the main which is usually in the center of the street. All of the leads from the house to the main were made of LEAD piping.
May very well answer your point.