Standard Guide for Conducting Laboratory Soil Toxicity Tests with the Nematode Caenorhabditis elegans

Importancia y uso:

5.1 Soil toxicity tests provide information concerning the toxicity and bioavailability of chemicals associated with soils to terrestrial organisms. As important members of the soil fauna, nematodes have a number of characteristics that make them appropriate organisms for use in the assessment of potentially hazardous soils. Bacterial-feeding nematodes such as C. elegans feed on soil microbes and contribute to the breakdown of organic matter. They are also of extreme importance in the cycling and degradation of key nutrients in soil ecosystems (9). Soil nematodes also serve as a source of prey and nutrients for fauna and microflora such as soil nematophagous fungi (10). A major change in the abundance of soil invertebrates such as nematodes, either as a food source or as organisms functioning properly in trophic energy transfer and nutrient cycling, could have serious adverse ecological effects on the entire terrestrial system.

5.2 Results from soil tests might be an important consideration when assessing the hazards of materials to terrestrial organisms.

5.3 The soil test might be used to determine the temporal or spatial distribution of soil toxicity. Test methods can be used to detect horizontal and vertical gradients in toxicity.

5.4 Results of soil tests could be used to compare the sensitivities of different species.

5.5 An understanding of the effect of these parameters on toxicity may be gained by varying soil characteristics such as pH, clay content, and organic material.

5.6 Results of soil tests may be useful in helping to predict the effects likely to occur with terrestrial organisms in field situations.

5.6.1 Field surveys can be designed to provide either a qualitative or quantitative evaluation of biological effects within a site or among sites.

5.6.2 Soil surveys evaluating biological effects are usually part of more comprehensive analyses of biological, chemical, geological, and hydrographic conditions. Statistical correlation can be improved and costs reduced if subsamples of soil for laboratory tests, geochemical analyses, and community structure are taken simultaneously from the same grab of the same site.

5.7 Soil toxicity tests can be an important tool for making decisions regarding the extent of remedial action necessary for contaminated terrestrial sites.

Subcomité:

E50.47

Volúmen:

11.09

Número ICS:

13.080.30 (Biological properties of soil)