title: Uptake, translocation, and elimination in sediment-rooted macrophytes: a model-supported analysis of whole sediment test data.
abstract: Understanding bioaccumulation in sediment-rooted macrophytes is crucial for the development of sediment toxicity tests using macrophytes. Here, we explore bioaccumulation in sediment-rooted macrophytes by tracking and modeling chemical flows of chlorpyrifos, linuron, and six PCBs in water-sediment-macrophyte systems. Chemical fluxes across the interfaces between pore water, overlying water, shoots, and roots were modeled using a novel multicompartment model. The modeling yielded the first mass-transfer parameter set reported for bioaccumulation by sediment-rooted macrophytes, with satisfactory narrow confidence limits for more than half of the estimated parameters. Exposure via the water column led to rapid uptake by Elodea canadensis and Myriophyllum spicatum shoots, followed by transport to the roots within 1-3 days, after which tissue concentrations gradually declined. Translocation played an important role in the exchange between shoots and roots. Exposure via spiked sediment led to gradual uptake by the roots, but subsequent transport to the shoots and overlying water remained limited for the chemicals studied. These contrasting patterns show that exposure is sensitive to test set up, chemical properties, and species traits. Although field-concentrations in water and sediment will differ from those in the tests, the model parameters can be assumed applicable for modeling exposure to macrophytes in the field.
authors.affiliation: Aquatic Ecology and Water Quality Management Group, Wageningen University , P.O Box 47, 6700 AA Wageningen, The Netherlands.
authors.forename: Noël J
authors.initials: NJ
authors.lastname: Diepens
authors.forename: Gertie H P
authors.initials: GH
authors.lastname: Arts
authors.forename: Andreas
authors.initials: A
authors.lastname: Focks
authors.forename: Albert A
authors.initials: AA
authors.lastname: Koelmans
mesh_terms: D004390:Chlorpyrifos / Q000032:analysis / Q000378:metabolism*; D019015:Geologic Sediments / Q000032:analysis; D031321:Hydrocharitaceae / Q000378:metabolism*; D008044:Linuron / Q000032:analysis / Q000378:metabolism*; D019684:Magnoliopsida; D008962:Models, Theoretical; D018517:Plant Roots / Q000378:metabolism; D018520:Plant Shoots / Q000378:metabolism; D011078:Polychlorinated Biphenyls / Q000032:analysis / Q000378:metabolism*; D012989:Soil Pollutants / Q000032:analysis / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000378:metabolism
chemical_list: D012989:Soil Pollutants; D014874:Water Pollutants, Chemical; D008044:Linuron; D011078:Polychlorinated Biphenyls; D004390:Chlorpyrifos