Exposure of Chironomus riparius larvae to uranium: Effects on survival, development time, growth, and mouthpart deformities
Résumé
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 μg 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 μg U g-1 dry wt, respectively. An LC20 of 2.49 μg U g-1 dry wt (95% CI = 1.48-4.27), and an LC50 of 5.30 μg 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. © 2007 Elsevier Ltd. All rights reserved.
Mots clés
Bioassay
Concentration (process)
Contamination
Growth kinetics
Development delay
Growth inhibition
Mouthpart deformities
Sediment toxicity test
Uranium
uranium
Bioassay
bioassay
growth response
inhibition
insect
larval development
physiological response
pollution effect
pollution exposure
sediment pollution
survival
toxicity test
water pollution
article
Chironomidae
controlled study
deformity
developmental stage
growth rate
larva
nonhuman
physical chemistry
sedimentation rate
survival rate
water contamination
Animals
Geologic Sediments
Larva
Water Pollutants
Radioactive
Chironomus riparius