Locatiespecifieke ecologische risicobeoordeling - praktijkonderzoek met een kwantitatieve Triade-benadering

Current approaches for site-specific ecological risk assessment of soil pollution are based on the estimation of effects from the presence of contaminants in soil and biota, and literature toxicity data. Trends in assessment methods are directed to the application of biological tests, like bioassays and biological field observations. For this the framework of the Triad approach was adopted and transformed to fit quantitative data of different assessment tools. The Triad is composed of three elements, i.e. an assessment of risks from the presence of contaminants in the soil (substances directed approach), an assessment of risks from the results of bioassays with samples from the site, and biological field observations. In this report the results are presented from experimentally derived TRIAD data in order to test the applicability and expressiveness of the method. Four propositions were adopted: 1. a balanced Triad requires effort on all three Triad legs simultaneously, 2. parameters for risk assessment should be quantitative rather than integer expressions or text, 3. for efficient evaluation it is recommended to express all data on one scale, the so-called 'effects' scale, ranging from 0 to 1, and, 4. for efficiency reasons, a tiered approach is recommended, using 'simple' tests in the lower tiers and 'sophisticated' tests in the higher tiers. From the field investigations at contaminated sites, the conclusion was that the quantitative Triad approach is useful for structuring ecological risk assessment methods