Desire for Levels: Background Study for the Policy Document 'SettingEnvironmental Quality Standards for Water and Soil'

摘要

The report is meant to provide scientific support for setting environmentalquality objectives for water, sediment and soil. No quality criteria are being set in the report. Only options for decisions are given. Starting point is the policy document 'Omgaan met risico's' (Premises for Risk Management), in which long term quality objectives are chosen to be set equal to the 'Verwaarloosbaar Risico' (Negligible Risk) levels which, in turn, are chosen to be set equal to 1/100th of the 'Maximaal Aanvaardbaar Risico' (Maximum Acceptable Risk) levels. The report is restricted to the derivation of the maximum acceptable risk levels for 45 chemicals. Maximum acceptable risk levels for water are primarily derived from available chronic toxicity data, following an extrapolation procedure recommended by the 'Gezondheidsraad' (Health Council). For sediment no toxicity data are available. Maximum acceptable risk levels for sediment are derived indirectly from maximum acceptable risk levels for water, using the equilibrium partitioning method. To derive maximum acceptable risk levels for soil, ecotoxicological extrapolation methods similar to those used for water are used. In addition, maximum acceptable risk levels for soil are derived from maximum acceptable risk levels for water with the equilibrium partitioning method. The appendix to the document can also be obtained (PB91-198887).