The HAPEM 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 relationships, population data, and human activity pattern data to estimate an expected range of inhalation exposure concentrations for groups of individuals.

Three versions of this model are currently available: HAPEM5 and HAPEM6, and the latest version, HAPEM7.

• Download Model

• User's Guides for HAPEM5, HAPEM6, and HAPEM7.

• Supporting Documents. 

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

  • Background information, including the development of model versions since HAPEM4.

  • EPA Science Advisory Board review of the use of HAPEM4 in EPA's National-Scale Air Toxics Assessment for 1996, and material associated with that review.