title: Multimedia benchmarking analysis for three risk assessment models: RESRAD, MMSOILS, and MEPAS.
abstract: This paper is one in a series that describes results of a benchmarking analysis initiated by the Department of Energy (DOE) and the United States Environmental Protection Agency (EPA). An overview of the study is provided in a companion paper by Laniak et al. presented in this journal issue. The three models used in the study--RESRAD (DOE), MMSOILS (EPA), and MEPAS (DOE)--represent analytically-based tools that are used by the respective agencies for performing human exposure and health risk assessments. Both single media and multimedia benchmarking scenarios were developed and executed. In this paper, the multimedia scenario is examined. That scenario consists of a hypothetical landfill that initially contained uranium-238 and methylene chloride. The multimedia models predict the fate of these contaminants, plus the progeny of uranium-238, through the unsaturated zone, saturated zone, surface water, and atmosphere. Carcinogenic risks are calculated from exposure to the contaminants via multiple pathways. Results of the tests show that differences in model endpoint estimates arise from both differences in the models' mathematical formulations and assumptions related to the implementation of the scenarios.
authors.affiliation: Tetra Tech, Inc., Lafayette, California, USA.
authors.forename: W B
authors.initials: WB
authors.lastname: Mills
authors.forename: J J
authors.initials: JJ
authors.lastname: Cheng
authors.forename: J G
authors.initials: JG
authors.lastname: Droppo
authors.forename: E R
authors.initials: ER
authors.lastname: Faillace
authors.forename: E K
authors.initials: EK
authors.lastname: Gnanapragasam
authors.forename: R A
authors.initials: RA
authors.lastname: Johns
authors.forename: G F
authors.initials: GF
authors.lastname: Laniak
authors.forename: C S
authors.initials: CS
authors.lastname: Lew
authors.forename: D L
authors.initials: DL
authors.lastname: Strenge
authors.forename: J F
authors.initials: JF
authors.lastname: Sutherland
authors.forename: G
authors.initials: G
authors.lastname: Whelan
authors.forename: C
authors.initials: C
authors.lastname: Yu
mesh_terms: D000396:Air Pollutants, Radioactive / Q000009:adverse effects; D000465:Algorithms; D002273:Carcinogens / Q000009:adverse effects; D003246:Conservation of Energy Resources; D004781:Environmental Exposure; D005544:Forecasting; D006077:Government Agencies; D006207:Half-Life; D006262:Health; D006801:Humans; D008752:Methylene Chloride / Q000009:adverse effects; D008954:Models, Biological; D015233:Models, Statistical; D019212:Multimedia; D018570:Risk Assessment; D012989:Soil Pollutants / Q000009:adverse effects; D012990:Soil Pollutants, Radioactive / Q000009:adverse effects; D014481:United States; D014484:United States Environmental Protection Agency; D014501:Uranium / Q000009:adverse effects; D014875:Water Pollutants, Radioactive / Q000009:adverse effects
chemical_list: D000396:Air Pollutants, Radioactive; D002273:Carcinogens; D012989:Soil Pollutants; D012990:Soil Pollutants, Radioactive; D014875:Water Pollutants, Radioactive; D014501:Uranium; D008752:Methylene Chloride