WHEN AND WHY WAS THE INDICATOR DEVELOPED?

In the Netherlands, government policies have been aimed at reducing pesticide use by 50%. Related to this is the desire to correspondingly reduce the risk to aquatic systems of pesticide use. Both the Ministry of Agriculture and the Ministry of Environment have indicated the need for such inciators to measure environmental risk reduction over time. The Institute for Environmental Protection and Health (RIVM) has developed a pesticide indicator specific for acute aquatic risk (developed circa. 1997). Since the introduction of the Multi Year Crop Protection Plan in the Netherlands, the amount of pesticides used in the Netherlands has decreased by approximately 50%. One of the questions raised some years ago was: does a substantial decrease of the amount of pesticides used by the farmers have a proportional enhancement in the quality of the aquatic environment? To answer this question, an indicator for the acute risk of pesticides in the aquatic environment was developed. This indicator is the quotient of the predicted environmental concentration and the toxicity for a certain group of organisms, which is scaled for the area treated with a compound and includes all the pesticides used since 1984. The risk for algae and daphnids has declined by 40 % and for fish by 15%. Less than 20 pesticides accounted for approximately 85 % of the height of the indicator. The Ministry of Agriculture is also developing a set of overall environmental risk indicators that will be easy to communicate to politicians and, in 1999, published their first report. This report describes a group of indicators that are similar to the one described in the RIVM report. They are all acute indicators: Surface water- drift; daphnids, algae, fish and aquatic ecosystems Ground water- leaching; ground water organisms (e.g., crustaceans) or a 0.1 ug/L standard Soil surface- spraying (nomograms of Kenaga); bird