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This document on iron foundries has been published within the SPIN project. In this project information has been collected on industrial plants or industrial processes to afford support to governmental policy on emission reduction. This document contains information on the processes, emission sources, emissions to air and water, waste, emission factors, use of energy and energy factors, emission reduction, energy conservation, research on clean technology and standards and licences.

Six laboratories in four European countries (GER, GB, S, NL) have conducted an interlaboratory comparison study on the analysis of dioxins in cow's milk. The study comprised a cross comparison of standards and the analysis of the 2,3,7,8-substituded congeners of have used their own procedures and methods for fat and dioxin determination in biological samples, all using non-polar gas chromatography and medium to high resolution mass spectrometry (RP = 3.000-10.000). Quantification was preformed by the use of a common quantification standard mixture of the native PCDD/Fs (4 labs) or the own quantification standards (2 labs). Within- laboratory reproducibilities for the determination of the major toxic isomers and the total TCDD toxicity equivalence (TE) level were between 2 and 16% (relative standard deviation (RSD)) with a mean of 8%. The interlaboratory variability in TE values was less than 12% (RSD) for TE values between 2.8 and 10.4 pg/g milk fat. The reliability of participant standards was difficult to assess and probably less good than expected. Deviations between found and expected concentrations in these standards were on average within 25% and for some congeners to 50% in some laboratories, when quantified against a common standard.

The mineralization of 14-C Acetate was studied in bottles with fresh soil and groundwater. Addition of toxicants inhibited the formation of 14-CO2 and dose effect curves were obtained. The acetate mineralization was not inhibited by zinc, cadmium, K2CR2O7, chloropyrifos, and paraquat in an acid sandy soil at 1000 mg/kg dry soil. The IC10 is the toxicant concentration which inhibits 10% of the initial mineralization rate. The IC10 concentrations for 3,4-dichloroaniline, triphenyltin, and orthoxylene were 48, 96 and 730 mg/kg, respectively in the acid sandy soil. The IC10 of pentachlorophenol was measured in samples from the acid sandy soil and in several other soil and subsoil samples. The geometrical mean of the thirteen IC10 values was 16 mg pentachlorophenol/kg. A statistical method was used to calculate the PCP concentration above which 5% of the most sensitive acetate mineralizing communities in all soils are influenced. The best estimate of this concentration is 0.3 mg PCP/kg but to be on the safe side the 95% confidence level of this concentration is 25 mug/kg.

The effects of five compounds on the endogenous methane production of sediment samples of the river Rhine were examined. The concentrations of a toxicant that inhibited the methane production for 10% and 50% are called EC10 and EC50. Benzene, 1,2- dichloroethane, pentachlorophenol and chloroform had EC10 values of >10000, 860, 140 and 5.5 mg/kg dry sediment, respectively. These values are well above the actual field concentrations, so the methane production is not inhibited. In one experiment, added zinc was toxic at concentrations far below the present background concentration in the sediment (800 mg Zn/kg) with an EC10 of 48 mg Zn.kg. In a second experiment with another sediment, however, the EC10 value was 1780 mg/kg. The difference in sensitivity is probably due to a different availability of zinc in the two experiments. Factors that govern the speciation of zinc in the sediment (e.g. the concentration of sulfide) are thus important when considering possible effects of zinc on microbial activity. Insight in these mechanisms, which also apply for other heavy metals, is needed as it was shown that zinc can be toxic at very low concentrations.

The toxic effects of 5 toxicants on 5 anaerobic microbial processes in fresh water sediments were measured. Four 14-C labelled substrates were mineralized to 14-CO2 at concentrations from 1-4 mug/l in fresh sediment microcosms. The half-lives of the substrates acetate, benzoate and 4-monochlorophenol were 12-30, 24, and 84 min. respectively. The chloroform mineralization was much slower with a half-life of 4.5 - 12 days. The natural methane production in the sediment was also used to measure the toxic effects. A dangerous Concentration 5% (DC5) can be calculated from the toxicity data using methods previously adapted for single animal species toxicity tests. Above this toxicant concentration more than 5% of the possible mineralization reactions can be partly inhibited. The HC5 concentrations for benzene, pentachlorophenol, 1,2-dichloroethane, chloroform and zinc are 1, 0.39, 0.0004, 0.0001 and 270 mg/kg sediment dry weight respectively. The chlorinated alkanes are much more toxic for anaerobic micro-organisms than for aerobic fish.

Within the framework of the project "Evaluation of decontaminated soil", the applicability of bioassays with earthworms and plants for the quality assessment of decontaminated soil is investigated. In order to establish a reference system for "normal" levels of metals in earthworms, radish and lettuce, bioassays with these organisms were applied to relatively unpolluted soils from nature reserve areas in the Netherlands. Such reference levels can be used to evaluate the results bioassays on decontaminated soils. Nineteen elements were analysed: As, Ba, Ca, Cd, Co, Cr, Cu, Hg, K, Mg, Mo, Na, Ni, Pb, Sb, Se, Sn, V, Zn. The concentrations of these elements (except for As, Cu, Hg, Ni en Pb) and the content of clay and the pH of the soils were lower compared to a study of Edelman (1983) on the same soils. The content of organic carbon was, however, higher. The soil concentrations of all elements appeared to be significantly correlated with the pH and the contents of clay and organic carbon of the soils. Also the availability, expressed as the concentrations in pore water sampled after the bioassays with earthworms, appeared to be correlated with a combination of these three soil characteristics. For most elements, bioavailability determined as the concentrations in earthworms, radish roots, radish tops and lettuce was also significantly correlated with a combination of these soil characteristics. The results of the Microtox-test, which was applied to the soil pore water, could not be explained by the pore water characteristics (pH, conductivity). These results and data gathered from the literature were used to formulate a proposal for a reference system of "normal" concentrations of elements in earthworms, radish roots and radish tops. Growth of lettuce was severely hampered, especially on acid soils; therefore lettuce was considered to be less suitable as a test plant. It is concluded, that the soil type correction presently used in the Dutch soil protection policy needs to be expanded with soil pH in addition to the contents of clay and organic matter presently used.

In the Netherlands a process of defining environmental standards is going on. These standards serve to protect the environment at the one hand, and to stimulate the reuse of rest-materials, e.g. ash from blast-furnaces, as building materials at the other hand. In order to come to an environmental legislation, quality-goals have been established for soil and (ground)water. Trustworthy and widely accepted testing methods are necessary to control the standards and to verify the quality-goals. Experimental verification has to be supported by theoretical modelling of physical and (bio-) chemical processes. Moreover, mathematical models are powerful tools for the prediction of the effect of the standards at the long range, when the duration or costs of experimental verification can be prohibitive. Therefore, a computer model that simulates the burden on an underlying soil of a reused waste-material has been developed. The model simulates coupled transport and behaviour of a set of chemical components. These components are assumed to be in mutual chemical equilibrium. Transport is assumed to occur by advection and dispersion. Equilibrium speciation of the components in aqueous solution is modelled by minimization of the chemical potential. The model code name is TRAMIN, from TRAnsport and MINeql. The MINEQL code, been attached to the transport module, MINimizes the chemical potential of a set of components in EQuiLibrium. The model has been used to simulate a laboratory experiment. From this application it appears that the existing data base should be extended with respect to complexation and precipitation and with respect to soil dependent sorption. Lack of a description for surface layer sorption prevented the modelling of iron-oxide, which was also a constituent of the percolate and the soil matrix. Further developments are continued, in close cooperation with the Agricultural University of Wageningen.

Scenarios are a way of creating alternative pictures of possible and desirable futures in the field of public health and health care. In preparing scenarios use can be made of models, especially mathematical models. Firstly, a review of the use of mathematical models in disease epidemiology studies by the STG is given. The STG is the Steering committee on Future health scenarios in the Netherlands. Secondly, an introduction in modelling, especially mathematical modelling, is given. The following topics are to be discussed: a system, a model, the cycle of building models, markov models and the validation of models. Thirdly, a review of models currently used in describing demography, disease epidemiology, risk and health care is presented. Finally, the link between mathematical modelling and the methodological aspects of scenarios is to be discussed.

Mathematical models play an important role in support of the preparation of policies and decision-making in health and environment. A major objective for the near future is to pay more attention to modelling quality assurance (MODQUA). Within the framework of the research project MODQUA the need of guidelines to the process of development and application of models has been investigated. This study revealed four main topics, which ask for the formulation of specific quality control criteria. Firstly, a software quality assurance plan is required. Secondly, the ease of use of the software package needs to be guaranteed. The administrative quality control of model calculations including input scenarios is another important item. Undoubtedly, the quality of the mathematical model itself is a key factor and makes the availability of methods, such as validation tools, for a systematic model analysis indispensable. It is recommended to start a pilot-study aimed at the integration and elaboration of criteria for these topics in practice.

Within the framework of the project "Evaluation of decontaminated soil", the applicability of bioassays with earthworms and plants for the quality assessment of decontaminated soil is investigated. In the final phase of this project, bioassays with earthworms and plants (radish, lettuce) developed earlier, were applied to a number of polluted and decontaminated soils. As earlier studies demonstrated that bioavailability of metals increased due to clean-up operations, the decontaminated soils were inriched with some organic matter (compost) and incubated for some months. Finally, the Microtox-test was applied to all soils. The results show, that concentrations of the metals As, Cd, Cu, Pb and Zn in the test organisms were lower on decontaminated soil compared to polluted soil. Also the results of the Microtox-test showed a reduction of the toxicity for most decontaminated soils. Addition of compost to the soils led to a further quality improvement, as was demonstrated both by lower metal concentrations in the tests organisms and by the results of the Microtox-test. On these enriched soils, however, growth of lettuce appeared to be severely inhibited; this cannot be explained. In most cases the metal concentrations in earthworms and plants cultured on polluted soils exceeded the "normal" values, which were established on the basis of bioassays in relatively unpolluted soils. Sometimes, this was also the case on decontamintated soil; not the enriched soils. Bioavailability of metals, expressed as the concentration factor, appeared to increase due to soil clean-up, but decreased again in the enriched decontaminated soils. This confirms results of earlier studies.

Within the framework of the development of a risk assessment system for new chemical substances, estimation methods concerning exposure of man and environment through air have been investigated. The pathways through which exposure through air takes place in this risk assessment system are exposure of human beings by inhalation and exposure of soils by deposition. Previous research (Noordijk & De Leeuw, 1991) has shown that for new chemical substances the existing Operational Priority Substances (OPS) atmospheric transport model (Van Jaarsveld, 1990) is an appropriate tool for the estimation of atmospheric concentrations and deposition fluxes, if some additional parameter estimation procedures are added. This concerns the estimation of the partitioning between gas phase and aerosol, the wash-out ratio, the dry deposition velocity and the atmospheric reaction rate. This report focusses on the implementation of the reported estimation methods within the risk assessment system, using the OPS-model. For this purpose, a simple table has been constructed reflecting simulated concentrations and deposition fluxes as a function of substance characteristics. In order to obtain information on variance in the results, a sensitivity analysis has been carried out for the main parameters and some source characteristics. Ranges of uncertainty are obtained through this analysis.

This report describes the initial hazard and risk assessment process for new substances at the National Institute of Public Health and Environmental Protection (RIVM) in the Netherlands. This assessment pertains to both man and the environment and is performed within the framework of the European Community (EC) Directive 79/831/EEC and the ensuing Dutch Chemical Substances Act. The report is restricted to the assessment of substances on the basis of the tests required at a market or production volume up to 100 tonnes per year or 500 tonnes cumulative. It has been written as a reference guide for those involved in the hazard and risk assessment process at RIVM in the first place, but also for the risk managers responsible for the regulation and the overall dossier evaluation of new substances, and for others interested in this subject, e.g. industry, non-governmental organizations and the public at large. Step by step the essential elements of the hazard and risk assessment process are discussed: organizational aspects, data requirements, the determination of the acceptability of the data received, the scientific evaluation of the test methods and results, the exposure assessment, the comparison of exposure and toxicity data, and the uncertainty analysis. The report also discusses requirements for further testing following the initial assessment and concludes with a summary of recent and relevant developments in the European Community within the field of the assessment of new substances.

The usual methods to determine organohalogenic compounds such as extractable organohalogens (EOX), adsorbable organohalogens (AOX) and purgeable organohalogens (POX) do not measure all polar compounds. A procedure is developed for the coulometric measurement of polar compounds in water. Samples with polar compounds are acidified to pH 1,5 and adsorbed on the resin XAD-4. The inorganic halogens are removed by washing with nitrate solution. The XAD-4 columns are eluted with acetone. After combustion of the organohalogens in a furnace, the halogen content is measured coulometrically. The procedure is tested with trichloroacetic iced (TCA). The recovery by the AOX determination was about 25%, whereas the recovery by the new procedure was about 100%.

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