title: Water-sediment interactions for Hyalella azteca exposed to uranium-spiked sediment.
abstract: Data on the toxicity of uranium in sediments to Hyalella azteca and the effect of overlying water chemistry are limited. This study exposed H. azteca to sediments spiked with U (0-10,000 microg U/g dry weight) and five different overlying waters, which varied independently in hardness and alkalinity. Water pH had a major effect on U bioavailability and uptake by H. azteca. Uranium toxicity was higher when overlying water pH was low, while desorption of U into the overlying water increased with increasing pH. There appears to be little effect of Ca on U uptake, other than its influence on U speciation. Experiments with caged animals indicate that U accumulation and toxicity occur mainly through the dissolved phase rather than the solid phase. Uranium bioaccumulation is a more reliable indicator of U toxicity than U concentration in water or sediment. Uranium bioaccumulation in the H. azteca and U adsorption to sediment can be satisfactorily explained using saturation models.
authors: Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1, Canada. Lara.Alves@ec.gc.ca
authors: L C
authors: LC
authors: Alves
authors: U
authors: U
authors: Borgmann
authors: D G
authors: DG
authors: Dixon
mesh_terms: D033304:Amphipoda / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism; D000818:Animals; D005618:Fresh Water / Q000737:chemistry*; D019015:Geologic Sediments / Q000737:chemistry*; D007928:Lethal Dose 50; D014502:Uranyl Nitrate / Q000378:metabolism / Q000493:pharmacokinetics / Q000633:toxicity*
chemical_list: D014502:Uranyl Nitrate