By Janet Raloff
From Chicago, at the EPA Emerging Pollutants Workshop
The standard test to evaluate whether metal-laden products are hazardous fails to flag high concentrations of lead in some discarded electronics equipment, new studies show.
“It was a surprise,” says Timothy Townsend of the University of Florida in Gainesville. On the other hand, the data are consistent with findings by others for certain metal-foundry wastes, he says.
Under the acidic conditions in many landfills, electronic gadgetry can leach lead and other toxic metals. To test an object’s potential to leach metal, federal guidelines require that it be crushed into pieces smaller than 1 cubic centimeter and soaked for 18 hours in a vinegar-strength acid bath. Products that leach at least 5 milligrams of any toxic metal per liter of solution must be designated as hazardous waste when discarded. That usually requires keeping them out of municipal landfills.