The people working on the project are Randy Maddalena, Tom McKone, Deborah Bennett, and Agnes Bodnar
The Office of Air Quality Planning and Standards (OAQPS) of the U.S. Environmental Protection Agency (EPA) has the responsibility for the hazardous and criteria air pollutant programs described by sections 112 and 108 of the Clean Air Act (CAA). In response to aspects of these programs that require evaluation of health risks and environmental effects associated with air pollutant exposures, as well as scientific recommendations of the National Academy of Sciences (NRC, 1994), the Presidential/Congressional Commission on Risk Assessment and Risk Management (CRARM 1997), and Agency guidelines and policies, the OAQPS recognized the need for improved fate and transport, exposure, and risk modeling tools.
To support evaluations with a scientifically sound, flexible and user-friendly methodology, the Total Risk Integrated Methodology (TRIM), a time series modeling system with multimedia capabilities for assessing human health and ecological risks from hazardous and riteria air pollutants, is being developed. The TRIM design includes three modules: the Environmental Fate, Transport, and Ecological Exposure module, TRIM.FaTE; the human Exposure-Event module, TRIM.Expo; and, the Risk Characterization module, TRIM.Risk.
The first TRIM module to be developed, TRIM.FaTE, is a spatial compartmental mass balance model that describes the movement and transformation of pollutants over time, through a user-defined, bounded system that includes both biotic and abiotic compartments. TRIM.FaTE, the emphasis for which is air pollutants for which non-inhalation exposures are important, generates both media concentrations relevant to human pollutant exposures and exposure estimates relevant to ecological risk assessment. The Exposure-Event module, TRIM.Expo, can receive input from TRIM.FaTE or from air quality models or monitoring data. In TRIM.Expo, human exposures are evaluated by tracking population groups referred to as "cohorts" and their inhalation and ingestion through time and space.
For More Information...
A Status Report, which describes the current status of TRIM development activities, and draft Technical Support Documents for two of the three TRIM modules are available on the OAQPS web site at the following address:
1 Hazardous air pollutants (HAPs) are those pollutants listed under CAA section 112(b); currently, there are 188 HAPs. Criteria air pollutants are air pollutants for which national ambient air quality standards have been established under the CAA; at present, they are particulate matter, ozone, carbon monoxide, nitrogen oxides, sulfur dioxide, and lead.