Gabriel M. Filippelli of Indiana University-Purdue University Indianapolis conducted a literature review of studies of urban soils as a persistent source of lead poisoning, and also investigated the lead burden in the soils from a number of cities.

His findings reveal that older cities like Indianapolis have a very high lead burden resulting in a lead poisoning epidemic among their youngest citizens.

While acute lead poisoning from toys and direct ingestion of interior paint has received more publicity, these cases account for only a portion of children with lead poisoning, Filippelli said.

"These national numbers for chronic lead poisoning are staggering but the percentage of affected children in older urban areas is much higher than in rural areas or newer cities," Filippelli said in a statement.

"The blowing soil and dust young children ingest contains large amounts of lead from lead paint and leaded gasoline deposited decades ago, and from industrial contamination."

The study is published in the journal Applied Geochemistry.