research for RIJKSINSTITUUT VOOR VOLKSGEZONDHEID EN MILIEU man and environment NATIONAL INSTITUTE OF PUBLIC HEALTH AND THE ENVIRONMENT RIVM report 711701 023 Technical evaluation of the Intervention Values for Soil/sediment and Groundwater Human and ecotoxicological risk assessment and derivation of risk limits for soil, aquatic sediment and groundwater J.P.A. Lijzen, A.J. Baars, P.F. Otte, M.G.J. Rikken, F.A. Swartjes, E.M.J. Verbruggen and A.P. van Wezel February 2001 This investigation has been performed by account of The Ministry of Housing Spatial Planning and the Environment, Directorate General for the Environment (DGM), Directorate of Soil, Water and Rural Areas, within the framework of project 711701, Risk in relation to Soil Quality. RIVM, P.O. Box 1, 3720 BA Bilthoven, telephone: 31 - 30 - 274 91 11; fax: 31 - 30 - 274 29 71 page 2 of 147 RIVM report 711701 023 Abstract Intervention Values are generic soil quality standards used to classify historically contaminated soils (i.e. before 1987) as seriously contaminated in the framework of the Dutch Soil Protection Act. In 1994 Intervention Values were published for 70 (groups of) compounds. These values, based on potential risks to human health and ecosystems, are technically evaluated on the basis of recent scientific views and data on risk assessment. Serious Risk Concentrations (SRCs, formerly called SCC) are revised for soil and groundwater; in addition SRCs are derived for sediment. A policy phase will start in 2001 to determine how the results will be implemented for setting Intervention Values. Starting points for the derivation of SRCs, partly chosen because of the policy context in which the SRCs are used, are mentioned and discussed. The general procedure for deriving these risk limits is partly modified, especially for groundwater. The methodology for deriving SRCs for sediment is new, as sediment had not been considered separately earlier. All parts of the human and ecotoxicological risk assessment were evaluated and revised when necessary. For deriving the human risk limit (SRChuman) the model concepts for human exposure pathways (i.e. soil ingestion, crop consumption and inhalation of indoor air), the model input parameters (e.g. physicochemical data), and the human-toxicological Maximal Permissible Risk level (MPR) are revised. For deriving the ecotoxicological risk limits (SRCeco) the HC50s, the concentrations where 50% of the tested species/processes may encounter adverse effects, the procedure and data were revised. The lowest value for each of SRCeco and SRChuman is selected as the integrated SRC. Ecotoxicological risks more frequently determine the integrated SRCs for soil and sediment than human toxicological risks. For groundwater the integrated SRC is often based on ecotoxicological risks and on the maximum concentration in drinking water (when groundwater would be directly used for human consumption). The proposed risk limits for soil and sediment are higher and lower than the current Intervention Values for Soil/sediment. The proposed risk limits for groundwater are more often higher than lower compared to the current Intervention Values for Groundwater. It can be concluded that in the present report consistently derived human and ecotoxicological risk limits are given, which give a solid foundation for setting Intervention Values in the policy phase. RIVM report 711701 023 page 3 of 147 Preface The Intervention Values for Soil/sediment and Groundwater contamination were published in 1994 as part of the Dutch Soil Protection Act (VROM, 1994). To provide an up to date scientific basis for these values the Directorate General for the Environment commissioned the National Institute of Public Health and the Environment (RIVM) to carry out the project “Evaluation of Intervention Values for soil contamination”. This report represents an integration of the results obtained in subprojects, leading to revised human-toxicological and ecotoxicological risk limits for soil and groundwater, and newly proposed risk limits, especially for sediment. The reports providing the components for this integration are: • Ecotoxicological Serious Risk Concentrations for soil, sediment and (ground)water: updated proposals for first series of compounds (RIVM report 711701020; Verbruggen et al., 2001); • Re-evaluation of human-toxicological Maximum Permissible Risk levels (RIVM report 711701025; Baars et al., 2001); • Evaluation and revision of the CSOIL parameter set; proposed parameter set for human exposure modelling and deriving Intervention Values for the first series of compounds (RIVM report 711701021; Otte et al., 2001); • Evaluation of the most relevant model concepts for human exposure; proposals for updating the most relevant exposure routes of CSOIL (RIVM report 711701022; Rikken et al., 2001); • Risk assessment of historical soil contamination with cyanides; origin, potential human exposure and evaluation of Intervention Values (RIVM report 711701019; Köster, 2001); • Proposal for revised Intervention Values for petroleum hydrocarbons on base of fractions of petroleum hydrocarbons (RIVM report 711701015; Franken et al., 1999); • Accumulation of metal in plants as function of soil type (RIVM-report 711701024; Versluijs and Otte, in prep.). • Revision of the Intervention Value for lead; evaluation of the Intervention Values derived for Soil/sediment and Groundwater (RIVM report 711701013; Lijzen et al., 1999). We owe a debt of gratitude for the information, advice and remarks provided by the “expert group on ecotoxicological risk assessment” (J. Van Wensem, TCB-Secretariaat; D. Sijm and T. Traas, RIVM-CSR; J. Appelman, CTB; T. Brock, Alterra; S. Dogger, Gezondheidsraad; J.H. Faber, Alterra; K.H. den Haan, VNO/NCW-BMRO), M. Koene, Stichting Natuur en Milieu; A. Peijnenburg, RIKZ; E. Sneller, RIZA; W.J.M. van Tilborg, VNO/NCW-BMRO) and by the “expert group on human-toxicological risk assessment” (J. Vegter, TCB- Secretariaat; T. Crommentuijn, DGM-BWL; J.A. van Zorge, DGM-SAS; C.J.M. van de Bogaard, DGM-IMH; T. Fast ; D.H.J. van de Weerdt, GGD Regio IJssel-Vecht; R. van Doorn, GGD Rotterdam; J. Dolfing, Alterra; P.W. van Vliet, Gezondheidsraad; C. van de Guchte, RIZA; J. Wezenbeek, Grontmij; A. Boshoven, IWACO b.v.; W. Veerkamp, VNO/NCW-BMRO; Th. Vermeire, RIVM-CSR; J. Lijzen, RIVM-LBG). We are also indebted to the advice and critical remarks given by the members of the RIVM- Advisory Group Human-Toxicological MPRs: A.G.A.C. Knaap, G.J.A Speijers, and T.G. Vermeire. page 4 of 147 RIVM report 711701 023 Contents ABSTRACT ..............................................................................................................................2 PREFACE .................................................................................................................................3 CONTENTS ..............................................................................................................................4 SAMENVATTING ...................................................................................................................8 1 INTRODUCTION ..........................................................................................................13 1.1 Position of the Intervention Values in the Dutch Soil Protection Act 13 1.2 Evaluation of Intervention Values 14 1.2.1 Need for evaluation 14 1.2.2 Results in this report 14 1.2.3 Scientific and policy phases 15 1.3 Components of the evaluation 16 1.4 Starting points for the evaluation and derivation of risk limits (Serious Risk Concentrations) 17 1.4.1 Introduction 17 1.4.2 Realistic or worst case? 17 1.4.3 Protection goals for humans and ecosystems 17 1.4.4 Human exposure scenario and exposure routes 18 1.4.5 Exposure routes for ecosystems 19 1.4.6 Human background exposure 19 1.4.7 Other starting points 20 1.5 Reading guide 20 2 PROCEDURES FOR DERIVING SRCS FOR SOIL, AQUATIC SEDIMENT AND GROUNDWATER .................................................................................................................21 2.1 General procedure for deriving integrated SRCs 21 2.2 SRC for soil 22 2.3 SRC for aquatic sediment 22 2.4 Integrated SRC for groundwater 23 2.4.1 Introduction 23 2.4.2 Human exposure to groundwater 24 2.4.3 Ecotoxicological risks for (ground)water organisms and processes 25 2.4.4 Direct/indirect exposure to groundwater for plants and livestock 26 2.4.5 Equilibrium partitioning (EqP) 26 2.5 Soil type correction 26 2.6 Sum values for groups of compounds 28 2.7 Summary of the general procedure for deriving SRCs 29 3 REVISIONS OF PARAMETERS USED FOR EXPOSURE MODELLING ..........31 3.1 Introduction 31 3.2 Physicochemical parameters 31 3.2.1 Introduction 31 3.2.2 Molecular Weight, Solubility, Vapour Pressure, Henry’s law Constant and Acid Dissociation Constant32 RIVM report 711701 023 page 5 of 147 3.2.3 Octanol-water partition coefficient (logKow) 34 3.2.4 Organic carbon normalised soil-water partition coefficient (logKoc) 34 3.2.5 Bioconcentration factor crop/soil for metals (BCF) 36 3.2.6 Bioconcentration factor fish/surface water for metals (BCF fish) 37 3.2.7 Kp metals for soil 38 3.2.8 Kp metals for aquatic sediment 39 3.2.9 Permeation coefficient (Pe) 40 3.2.10 Relative oral absorption factor for soil (Fag) 40 3.3 CSOIL site and exposure parameters 41 3.3.1 Soil parameters 41 3.3.2 Site parameters 41 3.3.3 Exposure parameters 42 3.4 SEDISOIL site and exposure parameters 44 3.4.1 Sediment parameters 44 3.4.2 Exposure and site parameters 44 3.5 Principal revisions of input parameters