PARENT SESSION
MA4 The Use of Ecological Models and Concepts in Aquatic Higher Tier Risk Assessment.
9:00 AM to 12:30 PM, Monday, 07 May 2001
Session Chair: Paul van den Brink
Room 4

(032) PERPEST a model to Predict the Ecological Risks of PESTicides.

Van den Brink, Paul¹, Roelsma, Jan¹, Van Nes, Egbert², Scheffer, Marten², Brock, Theo¹, ^{1 2}

ABSTRACT- PERPEST is an effect model that predicts the effects of a certain pesticide on various (community) endpoints. In contrast to most effect models PERPEST is based on real data. For this a literature review of freshwater model ecosystem studies with insecticides and herbicides was performed to assess the NOECecosystem for individual compounds, and to evaluate the ecological consequences of exceeding these standards. Effects on various endpoints (e.g. community metabolism, phytoplankton, macro-invertebrates) were classified according to their magnitude and duration. This literature review resulted in a database containing the effects of 18 herbicides and 21 insecticides. It total 90 experiments (42 herbicide, 48 insecticide) were evaluated, resulting in 317 cases (155 herbicide, 162 insecticide). This database was used to construct the PERPEST model. In this model one can enter the relevant properties of the compound, concentration and type of ecosystem to be evaluated. The PERPEST model searches for analogous situations in the database and calculates a prediction using weighted averaging of the effects reported in most relevant literature references. PERPEST results in a prediction showing the probability of effects on the various groups. The model is integrated in a user friendly user interface and its first version will be presented on this meeting. The scientific background of the model, its strengths and limitations will be presented.

Key words: effect model, community, risk assessment, pesticides