The use of invertebrate soil fauna in monitoring pollutant effects

A critical review of biological parameters used to indicate pollutant impac t on soil quality was conducted. These parameters mention some soil inverte brates. The value of an indicative organism depends on its life expectancy, life style and specific importance. Nematodes, mites, collembolans, enchyt raeids, earthworms, isopods and molluscs are good potential biological indi cators. Biological indicators of bioaccumulation and biological indicators of effects (toxicological and ecological) can bq distinguished. Bioaccumula tion studies are difficult to interpret, as wide variations could be found, depending on taxonomic group, habitat, organ studied, soil type or even po llutant type. Some groups, such as Collembola, require in depth bioaccumula tion studies. It is suggested to use a pool of macro-concentrators, includi ng at least some earthworm, isopod and gastropod species. Toxicological ind icators have been well studied and their lethal and sublethal pollutant eff ects are well known. However, studies have focused on only a few species, s uch as the earthworm Eisenia foetida or the collembolan Folsomia candida. T hese studies should be extended to other zoological groups, as well as to s everal species from the same group, to generate a representative test batte ry. Exposure biomarkers and physiological change studies should be emphasis ed, as they act as very early warning systems of contamination. Data are cu rrently lacking on how soil biological processes malfunction due to polluti on. We need to explore the links between pollutant effects on soil fauna an d pollutant effects on soil functioning. Concerning ecological indicators, studies should develop sampling techniques and parameters, which are specif ic to ecotoxicological goals. Before-after impact control procedures should be carried out, to eliminate the background noise of the study site and on ly evaluate the influence of pollutants. On the other hand, ecological indi ces, such as taxonomic diversity or richness, should be used carefully espe cially concerning chronic pollution. Effects of pollutants on biological cy cle studies seem very promising, but need further information on the life h istory strategies of many species. Furthermore, the pollutant tolerance of rare species should be considered. The different types of biological indica tors yield complementary information on pollutant effects. They all need st andard procedures. In this context, studies should be extended and diversif ied, and associate bioaccumulation, toxicological and ecological indicators to provide better information on soil quality. (C) 2000 Editions scientifi ques et medicales Elsevier SAS.