New developments in the toxicity testing of soil organisms – protecting soil biodiversity
The currently applied environmental risk assessment procedure for pesticides in the European Union (EU) is highly standardised. To assess effects on soil organisms at the lowest tier, just one test substrate is used, OECD artificial soil, a mixture of sand, kaolinite clay and Sphagnum peat. Moistened and adjusted to neutral pH, this substrate is used in standard tests with earthworms, springtails, and predatory mites. However, the use of this approach has been criticised mainly for two reasons:
(1) The standard OECD soil is not representative for European agricultural soils, since – due to its properties – the bioavailability of chemicals is lower than in natural soils. Hence, risks may be underestimated.
(2) The battery of tests with three soil invertebrate species does not cover the diversity (and thus the functions) of natural soil organism communities.
In addition, other uncertainties of the current ERA process may affect the outcome of regulatory decisions. These caveats will be addressed in the present project that will be performed in close cooperation with the German Environment Agency.