title: Performance of the CalTOX fate and exposure model in a case study for a dioxin-contaminated site.
abstract: Soil with high levels of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) is found at contaminated sites all over the world. Transfer of PCDD/Fs from contaminated soil to the food chain could lead to elevated human exposure. As a complement to available monitoring data, multimedia fate and exposure modeling can be applied to support risk assessment of sites with PCDD/F contaminated soil. In this study, we evaluated the performance of the CalTOX fate and exposure model for 2,3,7,8-substituted PCDD/Fs against measured concentrations in air, soil, grass, carrots, potatoes, milk, meat, and eggs from a contaminated site in northern Sweden. The calculated total toxic equivalent (TEQ) concentrations agree with measurements within a factor of 10 for all exposure media but one. Results for individual congeners demonstrated that the model did not always perform well at describing key processes that mobilize PCDD/Fs out of soils, such as transfer into root crops and ingestion of soil by chickens. Uncertainty in only a small subset of input parameters affects the model output. Improved information and models describing transfer of soil particles onto leafy vegetation by rain splash and biotransfer factors for PCDD/Fs to milk, meat, and eggs are particular research needs to reduce uncertainties in model-based assessments.
authors.affiliation: ÅF Infrastructure, Linnégatan 9, SE-582 25, Linköping, Sweden.
authors.forename: Annika
authors.initials: A
authors.lastname: Åberg
authors.forename: Matthew
authors.initials: M
authors.lastname: MacLeod
authors.forename: Karin
authors.initials: K
authors.lastname: Wiberg
mesh_terms: D000818:Animals; D001572:Benzofurans / Q000032:analysis*; D002417:Cattle; D018552:Daucus carota / Q000737:chemistry; D000072338:Dibenzofurans, Polychlorinated; D004531:Eggs / Q000032:analysis; D004781:Environmental Exposure / Q000032:analysis*; D005506:Food Contamination / Q000032:analysis; D064371:Hazardous Waste Sites; D006801:Humans; D008460:Meat / Q000032:analysis; D008892:Milk / Q000737:chemistry; D008962:Models, Theoretical; D006109:Poaceae / Q000737:chemistry; D000072317:Polychlorinated Dibenzodioxins / Q000031:analogs & derivatives* / Q000032:analysis; D018570:Risk Assessment; D012989:Soil Pollutants / Q000032:analysis*; D011198:Solanum tuberosum / Q000737:chemistry; D013548:Sweden
chemical_list: D001572:Benzofurans; D000072338:Dibenzofurans, Polychlorinated; D000072317:Polychlorinated Dibenzodioxins; D012989:Soil Pollutants