More than 400 urban sites that may be highly contaminated with lead have remained unknown to local authorities for decades, a preliminary study suggests. If ingested or inhaled, tainted soil particles from such sites can be harmful, especially to children.
As part of his doctoral thesis at George Mason University in Fairfax, Va., William P. Eckel used old directories of factories and fire-insurance maps to locate the sites of 640 factories that smelted lead from car batteries and other sources between 1931 and 1964. Eckel, now with the Environmental Protection Agency, then cross-checked his list with records from state, regional, and federal environmental agencies.
The agencies were unaware of 430 of the sites, Eckel and his colleagues reported in San Diego on April 2 and in the April American Journal of Public Health. The researchers note that of the 170 similar smelting sites the EPA already knew about, 14 are on the Superfund National Priorities List for cleanup and 32 others have already been worked on.
Eckel took one soil sample at each of eight locations in Philadelphia and Baltimore neighborhoods and found that seven had concentrations of lead higher than 400 parts per million (ppm), the standard specified by the EPA for soil in residential areas. The soil from one site just two blocks from homes in North Philadelphia had a lead level of 2,550 ppm, more than 2 1/2 times the EPA’s accepted 1,000-ppm amount for industrial areas.
These few samples are “just the tip of the iceberg,” says team member Michael Rabinowitz of the Marine Biological Laboratory in Woods Hole, Mass. Determining whether any particular site actually poses health threats will require more extensive and rigorous testing, Eckel adds.