Lead in Air: Adjusting to a New Standard

Autor: Charles W. Schmidt
Rok vydání: 2010
Předmět:
Zdroj: Environmental Health Perspectives
ISSN: 1552-9924
0091-6765
Popis: When it comes to industrial lead processing, The Doe Run Company’s smelter is in a class by itself. Perched on the banks of the Mississippi River in Herculaneum, Missouri, the smelter’s blast furnaces convert vast amounts of lower-grade ore into more than 125,000 tons of nearly pure commercial-grade lead every year. In operation since 1982, this is both the nation’s largest primary lead smelter and its largest point source for lead emissions, with just over 59 tons of lead released to the air in 2005, according to the most recent figures from the National Emissions Inventory of the U.S. Environmental Protection Agency (EPA). By comparison, that year’s next-highest emitter—a Missouri lead recycling facility also operated by Doe Run—released 12.4 tons. Doe Run’s smelter in Herculaneum may be the nation’s largest point source for air lead emissions, but it’s not the only one. The National Emissions Inventory, whose next release is expected 31 December 2010, lists 200 facilities emitting between one-half and 1 ton of the metal annually and 139 facilities emitting more than 1 ton. These facilities, which include smelters, battery recyclers, metal foundries, power plants, and airports, represent new and ongoing sources of lead air pollution that will soon draw additional scrutiny from the EPA. Among them, only one—Doe Run’s Herculaneum smelter—put its surrounding community out of compliance under the original National Ambient Air Quality Standard (NAAQS, usually pronounced “nax”) for lead under the Clean Air Act. That will soon change, however, for in 2008, the EPA dropped the lead NAAQS for the first time in 30 years, from 1.5 μg/m3 to 0.15 μg/m3. States have until 2017 to meet the new standard. But if 2005–2007 emissions data hold, up to 18 additional locations will be out of attainment with the new lead NAAQS, including communities in Alabama, Colorado, Florida, Illinois, Indiana, Minnesota, Missouri, New Jersey, Ohio, Pennsylvania, Tennessee, and Texas. Meanwhile, the emergence of new nonattainment areas puts a spotlight on point sources, or identifiable sources of concentrated emissions, which—in the EPA’s view—account for the dominant share of lead air risks in the United States today. “It’s appropriate to infer that point sources—especially now with the removal of lead from gas—are the main routes of exposure to lead in outdoor air, at least in this country,” says Lewis Weinstock, group leader of the EPA Ambient Air Monitoring Group. That view puts the EPA squarely at odds with the lead industry. David Weinberg, a lawyer with Battery Council International (BCI), a trade group in Washington, DC, argues that “legacy” contamination from old leaded gas and house paint contributes more to elevated blood lead than point-source emissions do. Exposure to legacy lead occurs both by ingesting contaminated soils and by inhaling resuspended road dusts and soils. “We’re making tremendous strides controlling industrial lead emissions with closed-loop cycles,” Weinberg says. “And as you lower ambient levels of concern, historic sources—i.e., residual paint and gas contamination—become increasingly important.” Philip J. Landrigan, a pediatrician and lead researcher at Mount Sinai School of Medicine, points out, however, that the dominant source of exposure for a particular child depends on where the child lives. “It is very important to document lead emissions from all of these sources,” he says, “because even the smallest exposures to lead are now understood to cause damage to the developing brains of young children.”
Databáze: OpenAIRE
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