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Environmental Modeling Community of Practice

Past Additions and Updates to Exposure Assessment Models

Listed below are some of the additions and updates on the Environmental Modeling Community of Practice website prior to 2006. The most current updates are listed on the recent additions page.

January 20, 2005

  • Version 1.0 of EXPRESS (EXAMS - PRZM Exposure Simulation Shell) has been released. Prior to the development of EXPRESS, PRZM / EXAMS simulations could only be performed for a single crop and single water body at a time. EXPRESS has been designed to increase the speed and consistency of aquatic pesticide exposure modeling by permitting simulation of an unlimited number of crops and multiple crop-specific modeling "scenarios" in a single computer run.

June 23, 2004

  • Version 3.1.1 of WhAEM2000 has been released and includes the following new features:
    • USGS Digital Raster Graphics files (DRGs) in GeoTIFF format are now supported as base maps.
    • A tool for adding simple Wellhead Protection Areas (WHPAs) has been included.
  • See the WhAEM2000 Release Notes for software modification details.

September 15, 2003

  • PRZM version 3.12.1 has been released and includes improvements to the irrigation routine and output reports. See the PRZM3 Release Notes for a complete list of software updates.

July 28, 2003

  • Version 1.0 of the Multimedia, Multi-pathway, Multi-receptor Exposure and Risk Assessment (3MRA) software system (formerly FRAMES-HWIR) has been released. The 3MRA technology provides the ability to conduct screening-level risk-based assessment of potential human and ecological health risks resulting from chronic exposure to HWIR chemicals released from land-based waste management units. For information on changes made to the system, see the 3MRA Release Notes.

June 16, 2003

  • The latest version of PRZM has been released. Version 3.12 includes numerous updates and enhancements to the previously released beta version. In addition, PRZM3 can now be run from the command prompt on a variety of Windows operating systems. See the PRZM3 Release Notes for a complete list of changes to the software.

June 5, 2003

  • WhAEM2000 version 2.1.0 has been released and includes the following enhancements:
    • Improved access to Binary Base Map (BBM) files via CD-ROM and the Internet
    • Tools for converting and exporting ESRI shapefiles
    • Updated GFLOW1 solver
    • Improved BBM viewer displays hypsography and elevation values.
  • The Parameter Estimation (PEST) software was updated to version 6.05 and now offers:
    • Increased optimization efficiency
    • Significant additions and enhancements to TSPROC
    • Automatic User Intervention (AUI) for improved performance
    • New regularization utilities.
  • See the WhAEM2000 Release Notes or the PEST Release Notes for a detailed list of software modifications.

April 14, 2003

  • The Exposure Analysis Modeling System EXAMS version 2.98.04 was modified to include the "instantaneous peak value", i.e., the value generated by event loadings. The instantaneous peak value may include run-off events transferred from the PRZM program or drift from aerial spray operations. See the EXAMS Release Notes for detailed information.

  • Binary Base Map (BBM) files for use with the Wellhead Analytic Element Model WhAEM2000 system were updated to include hypsography (i.e., topographic contours) for selected quadrangles in Nebraska and Ohio. Hypsography should be available for additional states in the future

December 13, 2002

  • CEAM now includes a link to the OnSite site assessment tool which is offered on-line. OnSite was developed to provide modelers and model reviewers with prepackaged tools ("calculators") for performing site assessment calculations.

November 19, 2002

  • The latest version of The Exposure Analysis Modeling System (EXAMS) software model has been released. Version 2.98.04 includes:
    • Improved integration with meteorological input data
    • Additional output files and more control of output file production
    • New user-specifiable exposure event durations
    • Updated user manual and source code.

August 23, 2002

  • CEAM is pleased to announce the publication of a new set of meteorological data files that are compatible with the PRZM3, EXAMS, and PATRIOT software models also distributed by CEAM. The meteorological data files contain measurements taken at 237 weather stations located throughout the United States for a period extending from 1961 to 1990.

  • The CEAM-USERS automated mailing system formerly accessed through has been replaced by the new Lyris ListManager system. The new system contains the same list of subscribers as its predecessor but requires new commands to post messages and change preferences. To learn more about the new listserv system, visit the CEAM-USERS Listserv page

June 30, 2002

  • In response to an Agency-wide initiative, the EPA Center for Exposure Assessment Modeling (CEAM) Web site has been redesigned. The title of the website has been changed to "Exposure Assessment Models" and the site has been reorganized. Each exposure assessment model is now found in one of the following categories which can be accessed from the side bar found on the left of the page:

    • Groundwater Models
    • Surface Water Models
    • Food Chain Models
    • Multimedia Models.

    The basic content (i.e. models and data) remains unchanged, however, emphasis was placed on standardizing and simplifying the presentation of the models. Let us know what you think.