Exposure of Chironomus riparius larvae to uranium: effects on survival, development time, growth, and mouthpart deformities.
Among non-biologically essential metals, data concerning uranium effects on freshwater benthic macroinvertebrates are scarce. The effects of uranium on survival, development time, growth and mouthpart deformities of midge Chironomus riparius were investigated. A 10-day static laboratory bioassay was performed exposing first instar larvae to artificial sediment spiked with four concentrations of uranium (2.97; 6.07; 11.44; 23.84 microg U g(-1) dry wt). As uranium was released from the sediment to the overlying water during this bioassay, both the sediment and the water column act as contamination pathways in giving rise to the observed effects. Significant negative effects on survival, development time, and growth were detected at 6.07, 6.07 and 2.97 microg U g(-1) dry wt, respectively. An LC20 of 2.49 microg U g(-1) dry wt (95% CI=1.48-4.27), and an LC50 of 5.30 microg U g(-1) dry wt (95% CI=3.94-7.25) were estimated. With respect to effects of uranium on larvae mouthpart deformities, we found that the lower the concentrations, the higher the deformity rates. These results highlight the potential impact of uranium at population level in environmentally realistic concentrations.
Dias
Victor
V
Laboratoire de Radioécologie et d'Ecotoxicologie, Institut de Radioprotection et de Sûreté Nucléaire, DEI/SECRE, Cadarache bâtiment 186, BP 3, 13115 Saint Paul lez Durance Cedex, France. victor.dias@irsn.fr
Vasseur
Christophe
C
Bonzom
Jean-Marc
JM
D000818:Animals; D002683:Chironomidae / Q000187:drug effects* / Q000254:growth & development; D019015:Geologic Sediments; D007814:Larva / Q000187:drug effects / Q000254:growth & development; D014501:Uranium / Q000633:toxicity*; D014875:Water Pollutants, Radioactive / Q000633:toxicity*
D014875:Water Pollutants, Radioactive; D014501:Uranium