Respiratory Module Documentation for Inhalation Exposures Scenarios in the All Ages Lead Model (AALM)

The AALM respiratory module provides users with a means for estimating blood lead (Pb) concentrations and body Pb burden associated with exposures to Pb-laden aerosols. The module provides an introduction to human respiratory function, particle size characterization, particle deposition in and clearance from the human lungs, and absorption of Pb from particles into the blood. The module offers flexibility to handle for a wide range of inhaled particle characteristics (size, density, and solubility) and individual activities (rest, light exercise, and heavy exercise) during exposure. In SAB's August 2020 report, it was stated that, "Use of the model for scenarios with exposure to higher concentrations of larger, sometimes less soluble lead particles (e.g. at outdoor remediation sites or other occupational settings) is also desirable, and future development of the AALM should examine the utility of adapting the Multi-Path Particle Dosimetry Model (MPPD2 or subsequent iterations) to revise the respiratory tract model.” This respiratory module responds to the SAB recommendation with a new approach for assessing respiratory exposures to Pb-laden aerosols. 

Impact/Purpose

The AALM respiratory module provides users with a means for estimating blood lead (Pb) concentrations and body Pb burden associated with exposures to Pb-laden aerosols. This respiratory module responds an SAB review of AALM v2.0 recommendation with a new approach for assessing respiratory exposures to Pb-laden aerosols. 

Citation

Brown, James AND G. Diamond. Respiratory Module Documentation for Inhalation Exposures Scenarios in the All Ages Lead Model (AALM). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-24/224F, 2025.

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