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The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Ref ID : 5975

Laura S. Inouye, Robert P. Jones, and Anthony J. Bednar; Tungsten effects on survival, growth, and reproduction in the earthworm, Eisenia fetida. Environmental Toxicology & Chemistry 25(3):763-768, 2006

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To provide basic toxicity data for formulating risk characterization benchmarks, the effects of tungsten on survival, growth, and reproduction were investigated in the earthworm Eisenia fetida. Parallel studies with lead as a reference toxicant also were conducted. Although sodium tungstate (Na2WO4) was less acutely toxic than lead nitrate (Pb(NO3)2) in 14-day spiked field soil acute toxicity assays (lethal concentrations for 50% of organisms: W, 6,250 mg/kg; Pb, 2,490 mg/kg), tungstate completely inhibited reproduction in 28- and 56-day assays at all tested tungsten concentrations (>/_704 mg/kg). By comparison, cocoon production was not significantly reduced for lead concentrations until concentrations reached 766 mg/kg, and cocoon production was still observed at the highest concentration tested (1,650 mg/kg). These data indicate that tungsten is a reproductive toxicant for earthworms and that, by comparison, its sublethal toxicity is greater than that of lead. Toxicity data for other soil invertebrate species are required to fully establish benchmark levels/ecological soil screening levels for tungsten.