Maximum acceptable or maximum tolerable ecotoxicological risks are usually derived from alimited number of studies concerning single species under laboratory conditions. Laboratoryconditions may be very different from actual conditions in the field, and thus findings in thefield are often at variance with laboratory studies [35]. In field studies it has been found thatseveral factors which tend to be neglected in laboratory studies may strongly impact toxiceffects of soil pollutants. These include among others: density and adaptability of populationsof affected organisms, the presence of other environmental stress factors and the presence orabsence of specific landscape elements such as buffer strips [35].