EPA finalized revisions to the ambient monitoring requirements for measuring lead in the air on December 14, 2010. These amendments expanded the nation's lead monitoring network to better assess compliance with the 2008 National Ambient Air Quality Standards for lead. EPA required the continuation of monitoring at airports emitting at least one ton of lead per year. EPA also required the states to conduct a year-long monitoring study at 15 airports that emit less than one ton per year to determine how these sources impact air quality. The following documents are related to EPA's revisions to the ambient monitoring requirements for measuring lead in the air. In addition, materials are provided below on methods to calculate airport lead inventories, as well as air quality modeling of aircraft lead emissions.

• Fact Sheet: Program Overview on Airport Lead Monitoring (PDF) (4 pp, 215K, EPA-420-F-15-003, January 2015)
  This Program Summary provides a final summary of the data on concentrations of lead measured at 17 airport facilities in the U.S.
• Fact Sheet: Program Update on Airport Lead Monitoring (PDF) (4 pp, 210K, EPA-420-F-13-032, June 2013)
  This Program Update provided a summary of the data on concentrations of lead measured at 17 airport facilities in the U.S.
• Calculating Piston-Engine Aircraft Airport Inventories for Lead for the 2008 National Emissions Inventory (PDF) (22 pp, 738K, EPA-420-B-10-044, December 23, 2010)
  This Technical Support Document (TSD) provides the most recent methodology used to estimate airport-specific lead emissions for the 2008 National Emissions Inventory (NEI). 
• Development and Evaluation of an Air Quality Modeling Approach for Lead Emissions from Piston-Engine Aircraft Operating on Leaded Aviation Gasoline (PDF) (86 pp, 6.5MB, EPA-420-R-10-007, February 2010)
  This final report presents the results of EPA's study to develop a modeling approach to quantify how emissions from piston-engine aircraft affect ambient lead levels at the local scale.

• Memorandum on Selection of Airports for the Airport Monitoring Study (PDF)(40 pp, 15 MB, November 2010)