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Models
EPA scientists often use models to recreate the ways that pollutants, chemicals, and other substances affect human beings and the environment. Using models, researchers can estimate how a change in an element of the environment would affect the rest of the system. Scientists use the following models as part of EPA’s exposure research program:
- Dietary Exposure Potential Model
A downloadable model using existing food databases to estimate exposure to chemical residues. The model was developed for personal computers with data files designed in dBASEIV with FoxPro for Windows query and reporting applications. Though not intended for risk analysis, the model has proven to be a suitable tool for designing and interpreting exposure measurements, identifying data gaps, and establishing priorities for dietary exposure research. Updated April 2003. - Exposure Related Dose Estimating Model (ERDEM) for Assessing Human Exposure and Dose
ERDEM is a PC-based modeling framework that allows for using existing models and for building new physiologically-based pharmacokinetic (PBPK) and pharmacodynamic (PBPK/PD) models. The ERDEM framework provides a modeling tool for characterizing exposures of susceptible subpopulations, including infants and children, and calculating estimated internal doses. - Community Multiscale Air Quality model (CMAQ)
EPA's third generation air quality modeling system. The primary goals for the Models-3/Community Multiscale Air Quality (CMAQ) modeling system are to improve 1) the environmental management community's ability to evaluate the impact of air quality management practices for multiple pollutants at multiple scales and 2) the scientist's ability to better probe, understand, and simulate chemical and physical interactions in the atmosphere. - EPA Positive Matrix Factorization 3.0 (EPA PMF 3.0)
Receptor models such as EPA’s Positive Matrix Factorization (PMF) are used to support air quality standards by showing the sources for different air pollutants. The user provides a file of sample pollutant concentrations, which the model uses to calculate the number of source types, profiles, relative contributions, and a time series of contributions. The mathematical formulas used in EPA PMF to compute profiles and contributions have been peer reviewed by leading air quality management scientists and shown to be scientifically robust. - Ecosystems Research Environmental Simulation and Modeling
EPA scientists studying ecosystems use an array of models to learn how chemicals and compounds travel through and amass in ecosystems, and how these affect humans, animals, and plants that depend on them. - Center for Exposure Assessment Modeling (CEAM)
CEAM provides scientists with proven exposure models for accessing multi-pathway movement of contaminants in aquatic and terrestrial environments. CEAM distributes models and data base software for assessing exposure in groundwater, surface water, the food chain and in multiple environments (i.e., aquatic and terrestrial).
- Regulatory Environmental Modeling
EPA’s Council for Regulatory Environmental Modeling (CREM) was established in 2000 to promote consistency and consensus among environmental model developers and users. CREM’s website includes current models and guidance for environmental model development.