Air Pollution Control Program

Airborne Lead Information

Sources | Health Effects | Missouri's Lead Legacy | Lead Standard Revision
Boundary Recommendations | State Implementation Plans
Monitoring Information | Related Links

Sources
Lead is a metal found naturally in the environment, as well as in manufactured products. The major sources of lead emissions have historically been motor vehicles and industrial sources. As a result of the permanent phase-out of leaded gasoline and other national and state regulations, airborne lead concentrations have decreased in the U.S. by 94 percent between 1980 and 2007. Industrial processes are now the major source of airborne lead emissions, including lead smelters, waste incinerators, utilities, and lead-acid battery manufacturers. 

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Health Effects
While lead emissions have been greatly reduced nationwide, scientific evidence about the impact of lead on health has expanded dramatically since the U.S. Environmental Protection Agency or EPA first issued a lead standard in 1978. Lead can be emitted into the air in the form of particles small enough to stay suspended in the air. Lead emitted into the air can be inhaled directly or ingested after it settles onto surfaces or soils. Once in the body, lead is rapidly absorbed into the bloodstream and accumulates in the bones. Lead exposure is associated with several health effects that have an adverse impact on the cardiovascular system, central nervous system, kidneys, and immune system. 

Children are more susceptible to the damaging effects of airborne lead than adults because they breathe in more air per minute, typically spend more time outdoors, and exhibit greater hand-to-mouth activity than adults. Children are also more vulnerable to the health effects of lead because their minds and bodies are developing rapidly. 

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Missouri’s Lead Legacy
Missouri’s long history of lead mining and processing can be traced back to French explorers in the early 1700s. Missouri continues to be a world leader in lead mining and processing. Historical lead mining areas include the Old Lead Belt around Park Hills in St. Francois County and the Tri-State Lead area around Joplin in Jasper and Newton Counties. Lead continues to be mined from the New Lead Belt, or Viburnum Trend, located in Iron and Reynolds Counties. Herculaneum, located in Jefferson County, is the site of the nation’s only primary lead smelter. Glover and Buick, both located in Iron County, had primary lead smelting operations at one time. The smelter in Glover is no longer operating and the Buick facility is now used for secondary smelting, where lead is recycled from lead-acid batteries, picture tubes, spent ammunition, and other lead-bearing material. 

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Lead Standard Revision
On Oct. 15, 2008, the EPA promulgated a revised National Ambient Air Quality Standard or NAAQS for lead. The revision strengthened the 1978 standard tenfold, decreasing the standard for airborne lead from 1.5 to 0.15 micrograms per cubic meter. The significantly lower standard has the potential to affect more areas of the state, which will be determined using data from the Missouri Department of Natural Resource’s expanded monitoring network that became operational in January 2010. 

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Boundary Recommendations
The EPA requires each state to determine which areas in the state will not meet the 2008 NAAQS for lead, known as nonattainment areas. Herculaneum is the only nonattainment area in Missouri under the 1978 NAAQS. Missouri also has two maintenance areas located near Buick and Glover.  Doe Run operates the secondary smelter near Buick and owns the inactive primary smelter near Glover. The Buick and Herculaneum areas will clearly have difficulty meeting the new standard. The department presented a draft nonattainment recommendation at a public information session on Sept. 16, 2009, and at a formal public hearing on Oct. 29, 2009. On Dec. 3, 2009, the Missouri Air Conservation Commission adopted the department’s final recommendations. Based on current monitoring and modeling data, the department is recommending areas around Doe Run’s Herculaneum and Buick (portions of Dent, Iron and Reynolds Counties) facilities as nonattainment.  Other areas of the state with former and active lead mines are recommended as unclassifiable, including portions of Jasper, Jefferson, Newton, Reynolds, and St. Francois Counties. In December 2009, the department submitted the recommendation to EPA, which has one year to approve or modify it. EPA has the authority to make the final determination of nonattainment area boundaries. The current nonattainment boundary recommendation can be found on the National Ambient Air Quality Standard Area Boundary Designations page.

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State Implementation Plans
After the nonattainment area designations are finalized, states are required by the federal Clean Air Act or CAA to develop and maintain a state implementation plan or SIP that provides the state's air pollution control strategy for meeting the requirements of the CAA. The SIP is submitted to the EPA and includes the specific state rules and state plans that make up the state's air pollution control strategies. The 2007 SIP and 2009 SIP Supplement for Herculaneum can be found on the State Plans Pending EPA Approval page.

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Monitoring Information
Herculaneum Area Air Monitoring Sites
Viburnum Trend and Old Lead Belt Monitoring Sites
Tri-State Area Monitoring Sites
Preliminary 3-month Rolling Average Data

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Related Links

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