Kombinationswirkungen von Umweltchemikalien in der Ökotoxikologie

Ecosystems and biocoenoses are exposed to multiple mixtures of environmental pollutants, but the usual risk assessment of chemical toxicities is focussed only on the judgement of single substance toxicity. With the two biometrical models concentration-addition and independent action known from pharmacology and toxicology, a pragmatic way for the analysis of combined effects is possible using the experimental knowledge of single substance toxicity. A short introduction to the models is given and an appropriate experimental design for mixture toxicity analysis is outlined. The principal suitability of the concepts was verifed in two different bioassays (green alga; luminescent bacterium) with the analysis of binary and multiple mixture toxicities of environmental chemicals. In this paper we present the results obtained with the green algae bioassay. Congruent results from the bioluminescence inhibition assay can be found in Grimme (1998). The results obtained indicate that the toxicities of mixtures of chemicals can be studied experimentally, even at low concentrations of the individual components. Mixture toxicities were detected at low, statistically non-significantly acting concentrations of the single compounds. These results force one to take mixture toxicities into account when environmental standards are established.     

Morphologische Parameter als Biomarker in der Ökotoxikologie – natürliche und schadstoffinduzierte Variabilität

Background Ecotoxicology utilizes alterations of biological parameters of organisms as biomarkers of toxic exposure or effects. In environmental monitoring, biomarkers function as sensitive indicators of chemical pollution or as early warning signal of late effects Aim The pre-requisite for using a biological parameter as biomarker is the ability to unequivocally distinguish between the natural or normal and the induced or abnormal expression of the marker. This article discusses problems in discriminating between the normal and induce state, using morphological biomarkers as an example. Results and Discussion Morphological and/or anatomical parameters are intuitively considered to be rather invariable. This article shows for the example of gonad morphology of fish that this expectation is not always correct, but that morphological markers may display pronounced baseline variability. The reasons for this variability are often not understood. This is limiting the utility and interpretation of the biomarker response, in particular when organisms are not only exposed to chemical but to multiple stressors. Outlook The problem of discriminating between natural and induced variability of biomarkers is of particular relevance in low dose exposure scenarios, when stressors other than toxic chemicals may confound the toxicant-induced changes of the biomarker status. To better handle this problem and to be able to distinguish between adaptive and adverse changes, ecotoxicology has to set out for improved understanding of the phenotypic plasticity of organisms and genotypes,     

Ökologische Optimierungspotenziale der energetischen Nutzung von Palmöl

Aim and Background The use of palm oil for bioenergy has become increasingly important for Europe in the last years because of its favourable proportion of yield to area under cultivation. Thus, palm oil presents a low-priced alternative to other energy sources, e.?g. rapeseed oil. Currently, however, palm oil gets a bad press due to new studies about the negative environmental consequences of cultivation practices. Due to the high demand for palm oil, land is becoming scarce. This results in the clearing of primary forests and consequently in the loss of biodiversity and in an increase of greenhouse gas emissions. To reduce the latter, not only the process of oil palm cultivation has to be optimised but also the practice of establishing new plantations by clearing natural forests has to be questioned. The aim of this article is to disclose potentials for greenhouse gas reductions in existing as well as in newly-planned oil palm plantations. Results and Discussion For existing oil palm plantations, two main fields for possible optimisation can be identified: one is improving the plantation management, the other is increasing the efficiency of the utilisation of waste products such as fibres and husks or oil mill effluents. For newly-planned oil palm plantations alternative land use scenarios have to be considered. The results show a big potential for optimisation. Thus, the greenhouse gas balance improves slightly if plantations are run more efficiently. If the waste products are used to generate energy, there are significantly positive effects on the greenhouse gas balance, especially through the reduction of methane emissions. By running a plantation in a professional best-practice way, 4.8 t of greenhouse gases can be saved annually per hectare cultivation area, expressed as CO₂ equivalents. If newly-planned oil palm plantations are established on fallow land, greenhouse gas emissions can be further reduced by an additional 4.8 t of CO₂ equivalents per hectare and year. From an economic perspective, this may be more costly than clearing primary forest but it is advantageous for both the greenhouse gas balance and the biodiversity of the concerned areas. All in all, exploiting the whole potential for optimisation could result in the saving of 10.2 t CO₂ equivalents per hectare and year more than it is the case in the existing mode of cultivation. Conclusions and Perspectives Due to the high demand of palm oil by the world market, cultivation areas for oil palms are becoming increasingly scarce. Thus, it is vital to exploit the full potential of oil palm cultivation in an environmentally and economically sustainable way. The management of plantations has to be optimised and a generally valid waste management system must be implemented in existing and future plantations. New plantations should preferably be established on fallow land, not by the clearing of primary forests. It is essential for a sustainable palm oil production to tap the full potential for optimisation. This, however, is currently not happening due to the high start-up investments. It is thus recommended to introduce an internationally valid certification system which may provide an incentive for more sustainable and effective production methods.     

Raumbezug in der ökosystemaren Umweltbeobachtung

Using the example of the transboundary Biosphere Reserve Rhone, experiments were performed and expounded upon with regard to the concept of ‘integrated monitoring’. The paper describes the components of a step-by-step harmonisation of data sampling and analysis procedures. Special emphasis is given to topics dealing with suitable methods for a sound selection of areas and plots to be monitored, as well as on rules for the spatial integration and generalisation of sampling results. As tools for this purpose the concept of ‘integrated monitoring’ uses the federal ‘Classification System of Ecoregions’ (Standortökologische Raumgliederung) and geostatistical methods for the spatial integration of existing monitoring programmes and sampling grids. Further, the paper outlines how to judge the development of water catchment areas using existing data from hydrological analyses and by means of an ecosystem-oriented water balance model.     

Integration der monetären Kosten in Ökobilanzen

For assessing product system sustainability, ecological as well as economical and social criteria have to be considered. These are very different criteria and individual valuation plays an important role when they are being compared. This paper shows how the most important economic parameter, i.e. monetary cost, can be integrated into the ecobalances of product systems without individual valuation. To do this, the less costly of two different product systems is improved until it reaches the cost of the other. The two product systems are not compared on an equal technical basis (as is notmally the case), but on the basis of equal cost. The procedure can be explained using windows as an example, assessing their production, service life (with maintenance and heating) and recycling/disposal. Standard windows with good insulating properties made of PVC, wood and aluminium are taken as the starting point. When they are compared, the ecobalances of PVC and wood windows differ only slightly, with a little greater difference for aluminium windows. The ecobalance of the aluminium window, on the other hand, is significantly different from those of PVC and wood windows. The cost of the PVC window is much lower than that of the other two systems. Because of this, PVC windows are technically improved by introducing a more expensive but better insulating glass pane, leaving the PVC window system still cheaper than the other two systems, but with drastically improved ecobalance results. If product systems with different monetary costs are to be compared using ecobalances, we propose that this be performed on an equal economical rather than an equal technical basis. Monetary cost can thus be integrated into ecobalance studies.     

Biomonitoring zur wirkungsbezogenen Ermittlung der Schadstoffbelastung in terrestrischen Ökosystemen

Biomonitoring programmes provide relevant information, which may supplement ambient air pollution monitoring or modelling around emission sources. As a prerequisite, assessment scales for biomonitoring data have to be derived based on an objective evaluation of available data, as well as on a scheme of presentation, which is suggestive and easily understandable even for laymen. Based on an evaluation of numerous monitoring programmes, assessment scales for biomonitoring results are derived for plant biomonitoring, which also serve as a basis for the graphical presentation of monitoring results. This study is focussed on bioindicator plants like mosses (passive biomonitoring) and exposed lichens (active biomonitoring), in which 14 metal elements are investigated. As an example, data from a local biomonitoring network around a cement plant were used to demonstrate the use of the assessment scales derived and the presentation scheme developed. Data sets from about 15 moss and 24 lichen biomonitoring programmes, comprising more than 1000 specimens, were sorted by their pollutant characteristics in order to form the database. Data on the metal contents of species demonstrating similar values with respect to growth characteristics and habit, and representing background or low pollution levels, are aggregated and their statistical distributions are evaluated. Spacing of the assessment scales and their colour designations are derived from the 50-, 75-, 90- and 95-percentile values. Graphical presentation allows a comparison of the absolute values of metal contents and a relative association of measured values. Exemplary results from moss and lichen monitoring around a cement plant are generally below or slightly above the median values at background and low-pollution sites. Metal contents are higher in lichens compared to mosses for 7 elements (Cd, Cu, Hg, Pb, Sb, Sn, Zn), and are lower in lichens only for thallium. The assessment scheme presented is mainly aimed at the practitioner in the field of biomonitoring in order to provide a reliable and sound scale of assessment by comparison on an absolute scale rather than presenting the basis of ecological risk assessment. Differences in metal content of co-located samples of various moss species and possible correction procedures are briefly discussed- as well as the consequences of pooling monitoring data across various moss species for the quality of assessment scales. Further evaluations shall focus on species-specific rather than on pooled databases and will investigate the consequences of the use of correction factors when extrapolating metal data from one monitoring species to another.     

Ökonomisch-organisatorische Betrachtung der Klärschlammverwertung: Kosten — Nutzen — Ausstiegsszenarien

Goal and Scope

The controversial issue of disposing municipal sewage sludge on arable farmland and growing demand on derived fuels could result in a total or partial abandoning of sludge recycling as fertiliser. Alternative disposal strategies like incineration will cause complex changes. A material flow management framework is used to determine the economic-organisational consequences for public authorities, farmers, rural contractors, disposal firms, and population in Schleswig-Holstein.

Methods and Focus

The study is based upon network analysis, analysis of agricultural and wastewater statistics and interviews. After structuring the disposal process, transaction are used to derive costs of different disposal strategies. The purification technique of sewage plant and application of metal salts for precipitation affect the fertilising quality of sludge. Therefore, all plants are classified into 4 different technical groups with decreasing fertilising effect. Now, the amount of sludge and corresponding fertilising benefit is calculated both state wide and for typical farms. Finally costs of different disposal strategies are derived.

Results

Referring to sewage plants sludge disposal in Schleswig-Holstein is characterised by a local structure since less than 10% of all 841 sewage plants produce almost the entire sludge where as many small plants especially in rural areas produce only little amounts. Usually enriched with lime, dewatered sludge fulfilling legal limits is used as organic fertilizer. The number of transactions indicates the costs.

Discussion

To reduce transaction costs, disposal firms try to offer high quantities of sludge to a limited number of farmers. Due to purification technique, the fertilising effect of half the amount of total sludge is reduced. Compared to the total demand on phosphorous, sludge can only substitute up to 4% of phosphorous. Farmers can substitute up to 50% of mineral fertiliser and increase marginal income per hektare. Although changing disposal strategy to incineration would double economic costs, fee for wastewater would remain almost constant.

Conclusions

Small wastewater plants, farmers and rural contractors would be particularly affected by ceasing sludge disposal. Small wastewater plants would have to invest in dewatering equipment, rural contractors would lose an important market segment and farmers (only a small percentage of all farmers uses sludge) would lose additional income. Changing waste management from sludge disposal with many involved parties to e.g. incineration would considerably reduce transaction costs for authorities. In case of partly changing waste management strategy, whereas sludge of small plants could be recycled, the authorities would still have to plan and control the disposal process even for small quantities of sludge. Transaction costs do not decrease proportionally to the decreasing amount of sewage sludge.

Perspectives

Quality management systems initiated by disposal firms should increase the acceptance and prevent a ban of sludge recycling. Nevertheless, the waste market develops from material to energetic use of waste. Significant resources will be lost without a phosphorous recovering from sludge as well as from other organic waste.     

Umwelteigenschaften von Produkten Die Rolle der Ökobilanz in ISO Typ III Umweltdeklarationen

Goal and Scope

Type III Environmental declarations (Environmental product declarations, EPD) are intended to inform interested parties about the environmental performance characteristics of products. They are based mainly on LCA according to ISO 14040ff, provide its results as inventory or impact category indicators and thus describe the product system under investigation. ISO 14025 is out for ballot as FDIS. The concept of EPD has found a market in particular in the construction sector. It has a considerable part in the European Integrated Product Policy, e.g. documentation of improvement in design for environment, documentation of compliance with green procurement requirements.

Main Features

EPD are a means to communicate the results of a LCA-study according to ISO 14040ff in a comparable and harmonised way. ISO (FDIS) 14025 describes how to develop and document consistent and comparable data sets. This report exemplifies three levels in the development of EPD for which the standard provides requirements. 1. Framework for the development of an EPD program including verification procedures for EPD. 2. Defining the rules for conducting the LCA according to ISO 14040ff as well as additional information for defined product categories (product category rules). 3. Development and documentation of EPD according to the PCR.

Results and Conclusions

After quite a few years of standardisation work the new standard ISO (FDIS) 14025 will provide a systematic approach to documenting and communicating LCA results in an EPD. This will support propagating LCA from its academic origin to a practical tool for the assessment of the environmental performance of a product system. An essential part will be the participation of LCA experts in EPD programs.

Recommendations and Outlook

An enormous effort for developing appropriate conventions will have to be taken by all interested parties to come up with consistent and comparable EPD in different branches. In some areas defining such conventions has been shown to be possible. An important part is the development of quality criteria for modelling as well as for the databases used to calculate the LCA. To find sufficient credibility at economically acceptable conditions with a minimum of bureaucratic effort more practical experience will have to be gained. This holds especially for the trust in the EPD results based on the independence of the review, transparency of procedures and the participation of interested parties. There is a demand on education for SME developing EPD for their products as well as for the users of EPD on how to document EPD transparently and apply them properly.