Correlations between three methods for determining the toxicity of chemicals to earthworms

Abstract

Abstract Three different laboratory methods for determining the toxicity of chemicals to earthworms were tested with a variety of pesticides and other chemicals. These methods, proposed by the EEC (Determination of Ecotoxicity of Chemicals), were: the Contact Filter Paper Test, in which the skin contact toxicity is tested by placing the organisms on treated filter paper; the Artificial Soil Test, in which the toxicity by skin and gut uptake is determined by adding the earthworms to an artificial soil made of sand, clay mineral and peat; and the Artisol Test, in which the toxicity by skin and gut uptake is determined by placing the worms in an artificial substrate consisting of silica, water and glass balls. (In the Artisol Test, the earthworms ingest the silica paste as they do soil.) With several chemicals, the Artificial Soil Test was conducted as described in an early guideline of the BBA. This test is similar to that proposed by the EEC. Results from the Contact Filter Paper Test were poorly correlated to those obtained by the other two methods (correlation to the Artificial Soil Test, r=0.55; correlation to the Artisol Test, r=0.48). In contrast, there was a high correlation between the Artificial Soil Test and the Artisol Test (r=0.91). This indicated that the mode of uptake of the chemicals (skin uptake and/or gut uptake) may be the same. As the Artisol Test seems to be readily handled and standardised, it could be useful for obtaining reproducible data on the ecotoxicity of chemicals to earthworms.