The Feds have made 10 micrograms per deciliter of blood the maximum safe level. Even 5 micrograms are too much. This is not new, but the articles still come and probably will do so for another decade or two, unfortunately. Click for the latest article I have read. Here is an excerpt from the article:
"Some doctors say that the C.D.C. could act more aggressively to identify poisoning cases by lowering the threshold at which lead levels are considered elevated. That threshold is 10 micrograms per deciliter of blood in children under 6. But Dr. John Rosen, who founded the lead program at Montefiore Medical Center in the Bronx in 1972, said research had established that even at levels as low as 5 micrograms per deciliter, lead could cause irreversible impairment to intelligence quotient, motor skills and behavior."