Missouri is the Saudi Arabia of lead, and our last lead mine closed a few years ago. The reason is nearly all lead is recycled.or it could be that lead is a naturally occurring thing and any amount is not considered safe for developing people (commonly called babies). Soil can easily contain some amount of lead. And that's the tip of the iceberg.
Leads fun your body thinks it's calcium and tries to use it for the things calcium does. And the body like reusing calcium and not getting rid of it.
Even sixty years ago my father’s Grade A milk barn had no lead paint, which is somehow still good a half century after he died. Those walls got scrubbed twice a day. The milk was tested weekly or thereabouts, at random times by a milk inspector, who also inspected the barn and equipment. Everything was white, shiny and gleaming.
Third world countries can’t afford a complete system of food safety from field to table.