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Om te bepalen of de kwaliteit van een bodem geschikt is voor (her)gebruik, wordt een risicobeoordeling uitgevoerd. Daarmee wordt onder meer beoordeeld of de aanwezige metalen een risico vormen voor mens, plant en dier. Momenteel wordt hiervoor de totale concentratie van de aanwezige metalen gemeten. Bekend is echter dat niet al het aanwezige metaal schadelijke effecten veroorzaakt. Door de hoeveelheid metalen te bepalen die effecten kan veroorzaken, wordt de risicobeoordeling van metalen in land- en waterbodem verbeterd. Aanbevolen wordt een meetmethode met verdund salpeterzuur toe te passen waarmee dit kan. Het RIVM heeft een visiedocument opgesteld, waarin staat waar, hoe en waarom dit in het bodem- en waterbodembeleid mogelijk is. Het heeft de voorkeur de nieuwe werkwijze in de eerste stap van de risicobeoordeling voor land- en waterbodem te gebruiken. Met de voorgestelde methode wordt nauwkeuriger het deel van de metalen bepaald dat verantwoordelijk is voor effecten op organismen. Voor kwik in beide bodemsoorten blijkt deze methode vooralsnog niet geschikt. Geadviseerd wordt om uit te werken welke concentraties voor land- en waterbodem toelaatbaar zijn. Ook wordt aangeraden de consequenties van de voorgestelde methode in de eerste stap van de risicobeoordeling voor de uitvoering van het bodembeleid in de praktijk in beeld te brengen. De nieuwe werkwijze kan wel direct worden gebruikt als aanvullende risicobeoordeling (tweede stap) van land- en waterbodem en binnen het beleid voor de diepe plassen van de aankomende Omgevingswet.

Soils contaminated with volatile substances can affect the air quality in buildings located in the vicinity of these substances. This guidance describes measurement techniques and the corresponding risk assessment of volatile substances in air caused by soil pollution. The results form the basis for soil decision-making on remediation by the local authorities. The guidance describes in seven steps how health risks from volatile substances in contaminated soil can be assessed using air measurements in and around the house. Possible areas for taking measurements are the living room, the area under the ground floor and in the soil itself. For this, an effective study strategy is important. Before risk assessors begin measuring, they need to first determine whether it is worthwhile. Subsequently, they need to determine target and pre-condition prior to proceeding with measurement. This method is more effective than first measuring and subsequently adjusting target and pre-conditions. The report provides general instructions for the interpretation of obtained data. This guidance is not meant as a rigid protocol but as an aid for all who have to carry out the measurements and interpret results. Furthermore, the guidance can help those who have to decide about taking remedial measures based on risk assessment.

This report presents alternative emission limit values for inorganic components to be used in the revision of the Building Materials Decree (1999) in the Netherlands. Three key factors determine the emission limit value: (1) the environmental compartment under consideration, with its dimensions and the accounted for, (2) the desired level of environmental protection and (3) the scenario applying to the intended use of the construction material. Emission limit values have been derived here from modelled concentrations in soil, groundwater and surface water. The desired level of protection has been elaborated as a stand-still approach (based on quality target values and a risk-based approach (based on PNECs). Two exposure models were used for taking the effects of a time-dependent exposure of the soil to leached components into account, for vertical transport through the soil profile and for retardation of components in the soil profile. The PEARL model was used for binding described by equilibrium adsorption. The ORCHESTRA model was used for binding that also takes speciation into account. For surface water, a dilution factor was computed assuming a certain mixing zone, dependent on the size of the surface water. The consequences of the proposed alternative emission limit values have been estimated on the basis of information in a database containing results of leaching tests for construction materials. The alternatives proposed form the basis for a political decision-making process, where environmental protection will be balanced with other socio-economic concerns.

The aim of this study was to support the policy on preventive soil protection with information concerning potential sources of local soil pollution. This study was an extension to earlier inventories on (potential) sources of soil pollution (e.g. industrial areas, landfills, oil-storage tanks). The emissions to soil were determined for eight potential sources and, following, potential soil concentrations in the top layer of the soil were estimated. Where possible these calculated concentrations were compared with measurements. The following sources were selected: public sewerage systems, pipelines (for oil products), roads and motorways, railways, tramways, galvanised power pylons, surface treatments and building activities. The study focused on heavy metals, pesticides, polycyclic aromatic hydrocarbons, chlorinated hydrocarbons, aromatic hydrocarbons and oil products.Conclusions have been made on (1) the contribution of the sources to the total emissions to the soil and (2) to the expected exceedance of the target values of pollutants in soil near sources mentioned. The contribution of the eight sources to the total emissions to soil is between 1 and 15% for heavy metals, about 41% for PAHs and maximally 15% for mineral oil. From the point of view of soil protection, the following sources and substances warrant further attention: emissions of chlorinated hydrocarbons from public sewerage systems ; emission and dispersion of lead, zinc, PAHs and oil along motorways ; emission of copper along railways and tramways ; potential leaching of PAH's and oil from railways ; emission of dichloromethane to the soil during the cleaning of buildings or removal of paint ; and copper, chromium and PAHs leaching from impregnated wood to the soil.

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.

This report describes the research into the methodology of the indirect human exposure models using two risk assessment tools, EUSES and CSOIL. Alternatives are proposed to the methodology of the indirect human exposure models, considering that their validity often remains unclear. The current plant model proved to function as an appropriate exposure route from air and soil to crops. However, improvements such as adding the particle-bound transport to leaves and using separate parameters for roots and leaves are recommended. The two equations describing the indirect exposure via fish seem sufficiently valid. Nevertheless, measured data is uncertain and the equation for hydrophobic substances leaves room for improvement. Large uncertainties for meat and milk are to be expected in the model, especially for hydrophobic chemicals. The method estimating the purification factors for the ingestion of drinking water can be seen as being rough and near worst case in its application. This method must also be updated, preferably with more European experimental data. The ingestion of soil should also include the ingestion of house dust, because part of this dust originates in the soil. In addition to the mentioned improvements, this report proposes further research for the different exposure routes.