We've made some changes to EPA.gov. If the information you are looking for is not here, you may be able to find it on the EPA Web Archive or the January 19, 2017 Web Snapshot.

Human Exposure Modeling - Hazardous Air Pollutant Exposure Model (HAPEM)

The HAPEM model has been designed to estimate inhalation exposure for selected population groups to various air toxics. Through a series of calculation routines, the model makes use of ambient air concentration data, indoor/outdoor microenvironment concentration relationship data, population data, and human activity pattern data to estimate an expected range of inhalation exposure concentrations for groups of individuals.

Two versions of this model are currently available; HAPEM5 and HAPEM6.

  • Supporting Documents.  Development of microenvironmental factors for hazardous air pollutants in 37 microenvironments.

  • Search the EPA Archive for technical details about HAPEM4.Search EPA Archive
    • To read background information, including the development history for HAPEM use the search term: "Further Technical Details about HAPEM4"

    • Peer review of HAPEM4 is available in Appendix-K:  HAPEM4 Results of the National-Scale Air Toxics Assessment for 1996, DRAFT for EPA Science Advisory Board Review. To read it, use the seacrch team:   "NATA 1996 Science Advisory Board"