ASKING FOR THE INDICATOR FUNCTION OF BIOASSAYS EVALUATING SOIL CONTAMINATION - ARE BIOASSAY RESULTS REASONABLE SURROGATES OF EFFECTS ON SOIL MICROFLORA

In evaluating the biological effect of solid materials like soil a bac terial contact assay often shows higher sensitivity than elutriate tes ting. Results of the Bacillus cereus contact assay for some environmen tal important toxicants are presented in this article. A comparison wi th another heterotrophic soil bacterium, Arthrobacter globiformis, sho ws comparable sensitivity. In a bioassay approach organisms at the lev el of individuals or populations are exposed to soil material to deter mine the significance of contaminants. An investigation that incorpora tes community level processes in comparison with toxicity test results provides a better understanding of the indicator function of bioassay s. Comparison of soil bioassays (aqueous and solid phase) with ecologi cal parameters demonstrates the problems in predicting ecological effe cts of soil contamination. (C) 1998 Elsevier Science Ltd.