Bioavailability and toxicity of arsenic to earthworms in three soils

The acute toxicity of arsenate [As(V)] and arsenite [As(III)] to the earthworm Eisenia fetida was studied in three different soils in order to provide basic toxicity and bioavailability data for formulating risk characterization benchmarks. Arsenic biotransformation in earthworms was also investigated to understand the mechanisms by which these organisms mitigate arsenic toxicity. Arsenic was more toxic to earthworms in acidic soil than in the alkaline soil. Earthworms transformed As(V) to more toxic As(III) which has implications to soil health.