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Total Risk Integrated Methodology (TRIM) - General Information
The TRIM design includes three individual modules:
The Environmental Fate, Transport, and Ecological Exposure module, TRIM.FaTE, accounts for
movement of a chemical through a comprehensive system of discrete compartments (e.g., media and biota) that represent possible locations
of the chemical in the physical and biological environments of the modeled ecosystem and provides an inventory, over time, of a
chemical throughout the entire system. In addition to providing exposure estimates relevant to ecological risk assessment, TRIM.FaTE
generates media concentrations relevant to human ingestion exposures that can be used as input to the ingestion component of the ...
... Exposure-Event module, TRIM.Expo. In TRIM.Expo, human exposures are evaluated by tracking either randomly
selected individuals that represent an area's population or population groups referred to as "cohorts" and their inhalation and
ingestion through time and space. The inhalation component is currently available.
In the Risk Characterization module, TRIM.Risk, (not yet available) estimates of human
exposures or doses are characterized with regard to potential risk using the corresponding exposure- or dose-response relationships.
The TRIM.Risk module is also designed to characterize ecological risks from multimedia exposures. The output from TRIM.Risk is
intended to include documentation of the input data, assumptions in the analysis, and measures of uncertainty, as well as the
results of risk calculations and exposure analysis.
The uncertainty and variability features (e.g., sensitivity & Monte Carlo analysis) augment TRIM's capability for performing
iterative analyses. For example, the user may perform assessments varying from simple deterministic screening analyses using
conservative default parameters to refined and complex risk assessments where the impacts of parameter uncertainty and variability
are assessed for critical parameters.
Given the modular design of TRIM, the user selects any one or more of the modules for an assessment depending on their needs.
- For example, when performing a human health risk assessment for an air pollutant for which multimedia distribution is
not significant, it is recommended that TRIM.Expo-inhalation be applied to ambient concentration data or the output from
an air quality model external to TRIM (i.e., not TRIM.FaTE). The output from TRIM.Expo may then be input to TRIM.Risk
(when available) to perform the desired risk analyses.
- In the case of a multimedia air pollutant, such as mercury, the user may choose to run all three TRIM modules (when
available) to assess ecological risks posed by multi-pathway exposures from multiple media, as well as human ingestion
risks posed by exposure from multiple pathways.
In the development of TRIM, existing models and tools are being relied upon where possible. For example, EPA has incorporated TRIM
into EPA's MIMS, a modeling framework that accommodates
linkages among multiple models and the sharing of common tools and data.
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