ELSEVIER International Biodeterioration & Biodegradation, Vol. 39, No. 1 (1997) 55-59 0 1997 Elsevier Science Limited All rights reserved. Printed in Great Britain PII:SO964-8305(96)00064-9 0964-8305/97 $17.00+0.00 Effect of Storage Conditions of Soil on Ecotoxicological Assessment H. Ehrlichmann, A. Eisentriiger, M. Mdler & W. Dott zyxwvutsrqponmlkjihgfedcbaZY Institut ftir Hygiene und Umweltmedizin der Rheinisch- W estjiilischen Technischen Hochschule Aachen, PauweIsstr.30, D-52057 Aachen, Germany (Received 22 December 1995; accepted 27 November 1996) The bacterial bioluminescence and the Daphnia tests were used to assess toxicity of three different soil samples stored under various conditions. Depending on the kind of contaminants, e.g. heavy metals or hydrocarbons, on the nature of the vessel walls and on the storage temperature and time, non-uniform, but distinct differences in the results of ecotoxicological tests were observed. Soil samples contaminated with organic pollutants showed a decrease of toxicity along with a decrease of volatile organic compounds with time. In contrast, samples containing heavy metals showed an increase of toxicity with time. Results indicated that more attention should be given to storage conditions of soils used in ecotox- icological investigations. 0 1997 Elsevier Science Limited INTRODUCTION The area of chemical wasted soil in Europe is estimated to be approximately 210,00Okm* (Anonymous, 1995). Therefore, methods to assess toxic effects and, subsequently, restoration concepts are required. Besides the chemical analysis to identify the kind of soil contaminants and to determine their concentrations, a valid assessment also requires detailed information about toxicity and bioavailability. Established analytical and toxicological protocols are in use for the examination of water and waste water samples. However, little is known about the application of bioassays for the estimation of the toxic or ecotoxic effects of soil pollutants. Biological and ecological effects cannot be predicted on the basis of the concentrations of the pollutants in soil samples alone without an estimation of bioavailability. Thus, bioassays represent effective instruments to assess risk potentials by integrating the overall effects of all contaminants as well as the matrix effects of the sample. Our knowledge of the alterations undergone by soil samples during their storage or during the sampling procedures is inadequate. Considering that wasted soils remain more or less active when they are stored outside the original deposit, different storage conditions are likely to cause soil alterations, influencing the toxicity assessment. These alterations are attributed to either microbial activities or physico-chemical reactions (Biickle et al., 1991). Furthermore, interactions between biological and physicochemical reactions are also possible. In this present study we investigated the effect of soil storage conditions when they were tested for ecotoxicological assessment. MATERIALS AND METHODS Three different soils were selected for this study: ‘heavy metal soil’, soil contaminated with heavy metals, taken form a sewage-irrigation field (Rieselfeld Berlin Buch), ‘fuel oil soil’, contaminated with fuel oil, obtained from AFU (soil de-contamination company, Berlin), and ‘forest soil’, intact forest soil (Bucher Forst, Berlin). The soils were sieved, ground to pass a 1Omm screen and then ground another two times to pass through a 2mm screen. After homogenization, the soil samples were characterized for several physical and chemical 55