Abstract not available

Abstract not available

This report contains general information on mixtures of polychlorinated dibenzo-p-dioxins and -dibenzofurans (dioxins) considering standards, emissions, exposure levels and effect levels. The document also discusses the need and possibilities to reduce the risks related to this group of compounds. Dioxins includes 210 tricyclic chlorinated organic compounds in total. International Toxicity Equivalency Factors (-TEFs) are used to describe to toxicity of dioxins, expressed in toxic equivalents (I-TEQ) based on 2,3,7,8-TCDD, the most known compound. Information to quantify dioxin emissions is scarce ; they are not commercially produced nor applied, being formed in incineration and industrial processes. Based on 1990 figures, direct emissions to air, water and soil amount approximately 600, 4 and 3 g I-TEQ per year, respectively. Deposition and sludge application contribute significantly to the load of soil (approx. 330 g I-TEQ), whereas, the contamination of water bodies is largely determined by deposition and trans-boundary emissions (approx. 100-125 g I-TEQ). In total the amount of dioxins in the soil and sediment compartments has been increased in 1990 with approx. 330 and over 65-90 g I-TEQ, respectively. Information on the occurrence of dioxins in the environment is very limited. Based on estimated exposure levels (approx. 1-3 pg I-TEQ.kg-1 b.w. per day by food, which contributes 90-95% to the total exposure) dioxins are considered not to present a risk to humans, the TDI being 10 pg I-TEQ.kg-1 b.w. However, information is lacking to evaluate the risks for sucklings during breast-feeding. Generally the risks to ecosystems is limited and only locally ecosystems may be at risk. However, secondary poisoning can not be ruled out and foodchain effects may occur in both the aquatic and terrestric environment. As a result of policy measures emission to air will decrease to approx. 125 g I-TEQ per year by 2000, those to water and soil will be the same as in 1990. The yearly increase in dioxin content of the soil will then amount 0.1 ng I-TEQ.kg-1. Additional measures are possible.

As a result of the increasing emission of complexformers like EDTA (ethylenediaminetetra-acetic acid) or NTA (nitrilotri-acetec acid), the speciation characteristics of metals will change. In this study the effect of EDTA (in a synthetic medium) on the speciation and biological activity of copper has been studied. The experimental set-up was three-fold: -the determination of the copper speciation electrochemically (Differential Pulse Anodic Stripping Voltammetry) in combination with UV-destruction and ion-exchange (Chelex), -the determination of the biological activity of the algae Selenastrum capricornutum (photosynthesis) and with the Microtox-test (light inhibition), -modelling of the speciation pattern. The calculated "not-EDTA" bound copper gives a better description of the photosynthetic activity than total copper concentrations, but it can not be used quantitatively. The experimentally determined "chelex- bound" copper fraction seems to be a good descriptor of the observed changes in the photosynthetic activity of S. capricornutum. More research to the validity of this relation for other water types is desired to enable the possibility to generalize and to improve the extrapolation methods.

This report is an addendum to report no 725201005, in which human toxicological guideline values and daily intakes for man are derived based on of a search of the toxicological literature in order to derive C-values for soil. Maximum tolerable risk levels for the total intake of genotoxic carcinogens and toxicologically tolerable daily intakes for threshold compounds have been determined for the following compounds or groups of chemically related compounds: sulfides, anthracene, naphthalene, PAH (total), chlorinated PAH, oxidized PAH, mineral oil, and tetrahydrothiophene. In addition, the maximum tolerable risk level for benzene has been revised.

Prognoses of possible effects and risks of chemical emissions into the environment and calculation of the effects of countermeasures are often produced using mathematical models. Most models are developed to describe a part of the total source-to-effect chain or to give results for specific compartments. In this study the models available at the RIVM have been examined for their usefulness in an integrated chain model for the total source-effect-risk chain of lead and lead-210 (a radioactive isotope of lead, Pb-210) in the Dutch environment. An integrated chain model is defined here as a set of relatively complex, deterministic stand-alone models, which have been independently developed and later linked. This report presents a short survey of the emission sources and effects of lead. Inorganic lead is emitted to the atmosphere in rather large quantities by traffic and industrial plants. The source-to effect chain is only partly covered by the available models. On a local scale the incompleteness is restricted to relatively small parts of the chain, like the contamination and transfer of lead from groundwater to terrestrial plants. The development of an integrated chain model is very time consuming, therefore should only be developed if there is a specific demand. Hence it would be advisable to start a follow-up project with an inventory of the demands for integrated models to answer specific questions on lead and to determine what is required: either the development of an integrated chain model or a less detailed but more encompassing integral model.

Based on the results of an inventory of possible dioxin sources other than municipal solid waste (MCW) incinerators, a number of sources not previously measured, are selected for additional measurements. The results of all measurements carried out in the Netherlands, partly supplemented with data from the literature were then elaborated into a total estimate of the dioxin emissions in the Netherlands. In total, the emission to air in 1991 was 484 g I-TEQ. Of that total, the MSW incinerators emit the largest quantity, i.e. 80% of the total. The remainder of the estimated yearly emission is distributed over 16 different process categories. As a result of emission regulating developments it is expected that the dioxin emission in the year 2000 will be descreased to 58 g I-TEQ.

Over 200 nuclear power plants for commercial electricity production are presently operational in Europe. The 1986 accident with the nuclear power plant in Chernobyl has shown that severe accidents with a nuclear power plant can lead to a large scale contamination of Europe. This report is focussed on an integrated assessment of probabilistic cancer mortality risks due to possible accidental releases from the European nuclear power plants. For each of the European nuclear power plants the probability of accidental releases per year of operation is combined with the consequences in terms of the excess doses received over a lifetime (70 years). Risk estimates are restricted to cancer mortality and do not include immediate or short term deaths in the direct vicinity (< 5-10 km) of the plants. Countermeasures to reduce radiation doses are not considered. Location specific risks are presented in maps of Europe. The excess mortality risk due to the combined operation of the European nuclear power plants is estimated to be about 10 x 10-8 per year in Western Europe. Going East the risks increase gradually to over 1000 x 10-8 per year in regions of the former Soviet Union, where reactors of the Chernobyl type are located. The nuclear power plants in the East European countries dominate the estimated risk pattern and contribute at least 40-50% to the average risk in the West European countries. Improving the reactor safety in eastern European countries could lead to considerable reductions in estimated excess mortality risks. In western Europe the mortality risk might be reduced by a factor of two, and in eastern Europe by a factor of 100 to 1000.

This document on plastics processing industry 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.

This document on Milk and milk-products industry 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.