Download Human Exposure Model (HEM)
1. General Information
For general information about and documentation on the release of HEM-3, please see the HEM page.
2. Installation Instructions
- Hardware/Software Requirements. You can use HEM-3 (and the RTR summary programs) on any Windows™-based personal computer running Windows 98™ or later. Disk space requirements will depend on the number of census and meteorological files that you use. The zipped files of nationwide census and meteorological data are approximately 375 megabytes (MB). If using HEM-3 to model only plants in a single state, then only the census and meteorological data for that state need to be extracted from the zip file, and the model would require much less disk space. To use all the nationwide Census and meteorological files, 2.2 gigabytes of disk space are needed. The model also will need a minimum of 132 megabytes of RAM.
- Download documentation files from HEM home page, and review information on installing and configuring HEM-3.
- Download the executable zip file for either HEM-3 or Multi HEM-3 (or the RTR summary programs). (See Section 3 below).
- Select the directory into which to install HEM-3 and unzip/extract the executable file into that directory. This directory may be referred to as the default directory. An installation program allows the user to choose an installation directory, and the basic files needed to run HEM-3 will be placed in that directory. A number of subdirectories will also be created.
- To complete the installation of HEM-3, the Input Files provided in Section 3 below must be downloaded to your PC. Each .ZIP file needs to be unzipped, and the contents placed in a particular subdirectory of the installation directory. Place the Toxicity Value Files in the "Reference" subdirectory, the Census Files in the Census subdirectories (“Census_2010” or “Census_2000), and the Meteorological files in the "Metdata" subdirectory.
3. Software available for download:
Please read installation instructions below before installing files.
4. Input Files for HEM-3
Please read installation instructions above before installing files.
Toxicity Value Files (12/18/2018)(86 K) - These include a set of acute and chronic dose-response values compiled by OAQPS for purposes of RTR screening-level analyses; for some chemicals, surrogate values, identified based on policy considerations for these specific purposes, have been included. Users should review and confirm values are appropriate for their uses, making corrections or updates as needed prior to using. An accompanying file identifies the target organs associated with the chronic values.
- Census Files
- Meteorological Files