So long as the leaded steel is undisturbed, it poses minimal health concerns. But if workers weld, drill or otherwise manipulate the steel during installation or in repairs years from now, the lead in the coating may be released, posing serious health risks. These negative health effects include damage to the central nervous system, delayed reaction time and information processing, as well as digestive problems and nausea, according to Hugh Evans, a professor of environmental medicine at New York University.
And the lead can also leak into the environment, harming wildlife and potentially the general population by seeping into lakes and drinking water, Evans said.
American firms virtually never permit lead paint on their products mostly because the necessary health precautions make working with steel that contains lead paint prohibitively expensive.
There is an explicit ban on lead paint designed for consumer use or in retail products such as toys, Julie Vallese, a spokeswoman for the U.S. Consumer Product Safety Commission said.
Adley said that one of the importing firms had contaminated shipments from at least two different Chinese factories, and that leaded paint was also imported from factories outside China. He said there were at least three or four tainted shipments, each containing upwards of a dozen trucks carrying some leaded steel.
Adley said that before the shipments this year, in his 12 years working for KTA he cannot recall shipments of any substantial size containing such high amounts of lead.
The new presence of leaded steel may be rooted in changing global economics. In the past, American companies would order raw steel from China and paint it in the United States, nipping any lead paint issues in the bud. But today more products are being manufactured, painted and preassembled in China simply because it is cheaper.
The 2.6 tons of finished steel imported from China during the first half of 2007 represent 18 percent of all finished steel imports and an increase of 25 percent from the same period last year, according to an American Iron and Steel Institute report. Only Canada exports more steel to the United States, but that may soon change as well.
Whereas most of the consumer products like toys and toothpaste recalled this summer contained less than 2000 parts per million of lead – or about 0.002 percent lead – some samples of the Chinese steel contained up to 25 to 50 percent lead on the surface.
Lead paint was widely used in buildings in the United States through the 1980s and early 1990s, but has since been effectively banned because of the serious health hazards associated with it, both Adley and Damiano said.