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Model Report

Modeling Environment for Total Risk-2E

Last Revision Date: 07/11/2011 View as PDF
General Information Back to Top
Model Abbreviated Name:

MENTOR-2E
Model Extended Name:

Modeling Environment for Total Risk-2E
Model Overview/Abstract:
MENTOR-2E uses an integrated, mechanistically consistent source-to-dose-to-response modeling framework to quantify inhalation exposure and doses resulting from emergency events. It is an implementation of the MENTOR system that is focused towards modeling of the impacts of releases of chemical and biological agents. MENTOR-2E uses, as one of the options, the USEPA’s Stochastic Human Exposure and Dose Simulation (SHEDS) approach.

MENTOR-2E calculates exposure and dose profiles, while providing the ability to focus on mechanism-relevant time scales, specific administrative areas, and subpopulations of interest. This is achieved by combining information on release characteristics, demographic characteristics of the population that can be potentially impacted, indoor/outdoor air exchange rates, time-activity diaries, and biologically based dosimetry. It uses the two dimensional Monte-Carlo methodology to quantify variability and uncertainty in model inputs and outputs.

MENTOR-2E has been applied to date to simulate potential casualties resulting from hypothetical releases of anthrax. It has also been applied for studying secondary exposures in hospital emergency rooms.

Plans for Future Model Development

Keywords: Modeling ENvironment for TOtal Risk studies (MENTOR) for Emergency Events
Model Technical Contact Information:
EPA Contact:
Dan Vallero
USEPA, NERL
Vallero.Daniel@epamail.epa.gov
919-541-3306

Developer Contacts:
Dr. Panos Georgopoulos
panosg@fidelio.rutgers.edu
732-445-0159

Dr. Sastry Isukapalli
sastry@fidelio.rutgers.edu
732-445-0171

Dr. Paul Lioy
plioy@eohsi.rutgers.edu
732-445-0393

Computational Chemodynamics Laboratory
(www.ccl.rutgers.edu), EOHSI, a joint Institute of UMDNJ – R.W. Johnson Medical School and Rutgers University, 170 Frelinghuysen Rd., Piscataway, NJ 08854.

Model Homepage: http://www.ccl.rutgers.edu/mentor/ Exiting the EPA Site
Plans for further model development: Enhancements focus on modules for real-time estimation of exposures and risks, and to incorporate multiple levels of dynamics and mixings in different microenvironments such as hospitals. Enhancements also focus on incorporating approaches for facilitating real-time application of the model (e.g. by performing some stages of simulation a priori and using the saved outputs).

User Information Back to Top
Technical Requirements
Computer Hardware
Operational on multiple, alternative hardware platforms: Intel/AMD based PCs, Sun Workstations (e.g. Sparc), Linux servers or clusters, and Apple Macintosh computers. Minimum requirements: 10 GB free hard drive space, 512 MB RAM, and 500 MHz processor.
Compatible Operating Systems
Any of the following: Windows 2000/XP/Vista, Linux, Solaris, Mac OS X.
Other Software Required to Run the Model
Matlab version 6.5 or higher for Windows/Linux/Solaris/Mac OS X (Matlab statistical toolbox needed). Local or remote installation of Access or MySQL databases are needed. Depending on the application, SAS 8.0, C, or Fortran compilers may be needed. ArcGIS 8 is required for visualization.
Download Information
This model can be downloaded here exit EPA
Using the Model
Basic Model Inputs
Primary or secondary source characteristics (e.g. magnitude, location, and time-profile of sources), or concentration profiles (e.g. those obtained through atmospheric dispersion models)
Basic Model Outputs
Potential casualties, statistical measures of exposures and doses, etc.
User Support
User's Guide Available?
Not currently available; technical documents on the formulation and applications of MENTOR-2E are available at http://www.ccl.rutgers.edu/mentor/.exit EPA

Other User Documents
Selected publications describing the system and applications:

Georgopoulos P.G. and Lioy P.J. (2006). From theoretical aspects of human exposure and dose assessment to computational model implementation: The modeling environment for total risk studies (MENTOR). Journal of Toxicology and Environmental Health - Part B, Critical Reviews 9(6): 457-483.

Stenchikov G., Lahoti N., Diner D., Kahn R., Lioy P. and Georgopoulos P. (2006). Multiscale plume transport from the collapse of the World Trade Center on September 11, 2001. Environmental Fluid Mechanics 6(5): 425-450

Lioy P.J., Vallero D., Foley G., Georgopoulos P., Heiser J., Watson T., Reynolds M., Daloia J., Tong S. and Isukapalli S. (2007). A personal exposure study employing scripted activities and paths in conjunction with atmospheric releases of perfluorocarbon tracers in Manhattan, New York. Journal of Exposure Science and Environmental Epidemiology 17(5): 409-425

Georgopoulos P. (2008). A multiscale approach for assessing the interactions of environmental and biological systems in a holistic health risk assessment framework. Water, Air, and Soil Pollution: Focus 8(1): 3-21

Isukapalli S.S., Lioy P.J. and Georgopoulos P.G. (2008). Mechanistic modeling of emergency events: Assessing the impact of hypothetical releases of Anthrax. Risk Analysis 28(3): 723-740.

Laumbach R., Harris G., Kipen H., Georgopoulos P., Shade P., Efstathiou C., Isukapalli S., Galea S., Vlahov D. and Wartenberg D. (2009 – in press). Respiratory symptoms are not associated with estimated WTC plume intensity and respiratory symptoms among residents outside of lower Manhattan. American Journal of Epidemiology

User Qualifications
Bachelor’s degree in Environmental Science/Engineering, Chemical Engineering, Exposure Science, Meteorology, or related fields.

Model Science Back to Top
Problem Identification
There is a need for reducing uncertainty in computer models for estimating risks from exposures and doses resulting from emergency events. The reductions in uncertainty will enhance the use of these tools for planning and training purposes. Proper planning based on more complete interpretation and evaluation of available knowledge and experience can reduce public anxiety as well as increase confidence on behalf of the professionals responding to an adverse event.
The approach of MENTOR has been to develop, apply and evaluate state-of-the-art modeling methods for a wide range of environmental applications, that utilize existing models, when available, or provide new approaches to “fill gaps” in the source-to-dose sequence. MENTOR links state-of-the art predictive models of environmental fate/transport and of human exposure and dose; these models are coupled with up-to-date national, regional, and local databases of environmental, microenvironmental, biological, physiological, demographic, etc. parameters. Thus MENTOR is not a “new model”; it is an evolving open computational toolbox, containing both “pre-existing” and new tools, intended to facilitate consistent multiscale source-to-dose modeling of exposures to multiple contaminants, for individuals and populations.
Summary of Model Structure and Methods
MENTOR-2E uses the following eight steps in calculating exposures, doses, and potential casualties::

  1. Estimation of outdoor concentration levels of airborne contaminants.
  2. Estimation of local contaminant levels at the scale of interest (such as a census tract) or a conveniently defined grid..
  3. Characterization of attributes of populations (geographic density, age, gender, race, income, etc.).
  4. Development of activity event (or exposure event) sequences for each member of the sampled population or for each cohort for the exposure period.
  5. Estimation of personal exposure levels and temporal profiles of contaminants in various microenvironments (residences, offices, restaurants, vehicles, etc.).
  6. Calculation of appropriate inhalation rates for the members of the sample population by combining physiological attributes of study subjects and activities pursued during the individual exposure events.
  7. Calculation of target tissue dose through physiologically-based respiratory deposition modeling by estimating the intake of the contaminant.
  8. Estimation the probability of adverse impact (e.g. death, infection, etc.) for each simulated individual based on calculated dose and physiological attributes using existing dose-response relationships or biologically based dose response models
Model Evaluation
MENTOR-2E has been applied to study the impact of hypothetical releases of anthrax for the States of Delaware and New Jersey. The results were compared with those from other approaches and the output uncertainties resulting from a subset of uncertainties were characterized.

Peer reviewed journal publications and technical reports presenting the application of MENTOR-1A are available.

Key Limitations to Model Scope
The temporal extent of MENTOR-2E ranges from a few minutes to up to few days, depending on the type of emergency event scenario. The spatial resolution is currently up to a census block, and the extent can be up to regional scale.

Case Studies
Georgopoulos P.G. and Lioy P.J. (2006). From theoretical aspects of human exposure and dose assessment to computational model implementation: The modeling environment for total risk studies (MENTOR). Journal of Toxicology and Environmental Health - Part B, Critical Reviews 9(6): 457-483.

Stenchikov G., Lahoti N., Diner D., Kahn R., Lioy P. and Georgopoulos P. (2006). Multiscale plume transport from the collapse of the World Trade Center on September 11, 2001. Environmental Fluid Mechanics 6(5): 425-450

Lioy P.J., Vallero D., Foley G., Georgopoulos P., Heiser J., Watson T., Reynolds M., Daloia J., Tong S. and Isukapalli S. (2007). A personal exposure study employing scripted activities and paths in conjunction with atmospheric releases of perfluorocarbon tracers in Manhattan, New York. Journal of Exposure Science and Environmental Epidemiology 17(5): 409-425

Georgopoulos P. (2008). A multiscale approach for assessing the interactions of environmental and biological systems in a holistic health risk assessment framework. Water, Air, and Soil Pollution: Focus 8(1): 3-21

Isukapalli S.S., Lioy P.J. and Georgopoulos P.G. (2008). Mechanistic modeling of emergency events: Assessing the impact of hypothetical releases of Anthrax. Risk Analysis 28(3): 723-740.

Laumbach R., Harris G., Kipen H., Georgopoulos P., Shade P., Efstathiou C., Isukapalli S., Galea S., Vlahov D. and Wartenberg D. (2009 – in press). Respiratory symptoms are not associated with estimated WTC plume intensity and respiratory symptoms among residents outside of lower Manhattan. American Journal of Epidemiology


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