title: Uranium uptake and depuration in the aquatic invertebrate Chironomus tentans.
abstract: Evaluation of aqueous uranium (U) uptake and depuration in larvae of the midge Chironomus tentans were investigated in two separated experiments. First, a static-renewal experiment was performed with 10-d old C. tentans larvae exposed to 300 microg U/L. The animals steadily accumulated U (K(u) = 20.3) approaching steady-state conditions (BAF = 56) in approximately 9-11 d. However, accumulated U was readily depurated (K(d) = 0.36) with U tissue concentration decreasing rapidly within 3 d of the larvae being placed in clean water (t(1/2) = 1.9 d). Also, the growth of C. tentans larvae appeared to decrease after 6-11 d of U exposure, probably due to the reallocation of resources into U detoxification mechanisms. However, growth significantly increased once C. tentans were transferred to clean water. A separate short-term experiment was performed to evaluate the possible mechanism of U uptake in this invertebrate. Results suggested a passive mechanism of U uptake coupled with an active mechanism of U depuration but no details related to the type of mechanisms or pathway was investigated.
authors.affiliation: Toxicology Centre, 44 Campus Dr, University of Saskatchewan, Saskatoon, SK, S7N 5B3 Canada. jorgelina_muscatello@golder.com
authors.forename: Jorgelina R
authors.initials: JR
authors.lastname: Muscatello
authors.forename: Karsten
authors.initials: K
authors.lastname: Liber
mesh_terms: D000818:Animals; D002683:Chironomidae / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism*; D004784:Environmental Monitoring; D007814:Larva / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism; D014501:Uranium / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D014874:Water Pollutants, Chemical; D014501:Uranium