Bestimmung von Spurenstoffen in Niederschlagsproben

A precipitation network consisting of 15 sites as part of the national project SANA was established to document and characterize the spatial and temporal changes of pollutants in the precipitation of East Germany. Long-term data records show a significant decrease of sulfate and calcium in the precipitation. The acidity and the nitrogen-containing ions have been remained unchanged up to now.     

Bestimmung und Bewertung der Emissionen von PCDD/PCDF,PAK und kurzkettigen Aldehyden in den Brandgasen von Kerzen

Exhaust fumes of paraffin, beeswax and stearin candles without any further paint or decorative element were analysed for the toxicological important substance classes of PCDD/PCDF, PAH and short chain aldehydes. The candle waxes and wicks were investigated for chlorinated dioxins, furans and some known precursors. Toxicological risk assessment shows that emissions of the investigated candles are much lower than all administrative limitation values — even under “worst case conditions”. Thus, they do not produce a toxicological risk for human health.     

Tonminerale als Katalysatoren bei der Umwandlung von organischen Verbindungen

Clay minerals show a variety of reactive properties, which make them used in industrial processes but are mostly neglected in soil science. In this overview these various properties of clay minerals are listed. Thereby it shall be pointed out, that these capabilities can also be of some importance in soils.     

Bewertung von Monitoringdaten der Umweltprobenbank des Bundes mit der Hasse-Diagramm-Technik

On behalf of the Federal Environment Ministry the Federal Environmental Agency operates the German Environmental Specimen Bank (ESB), which targets are to record and evaluate pollution data of selected ecological systems. Scope of the present study is to check the possibilities of the Hasse diagram technique (HDT) for the assessment of ESB data, mainly with regard to evaluations and conclusions. Xenobiotic body burden in Bream musculature (Abramis brama), measured in 1997, was exemplary used to answer these questions. Focus was put on ecosystemic assessment. The results clearly show that HDT is a valuable method for the graphical display, interpretation and comparative evaluation of pollution data. HDT visualises data qualitatively and in summary. Additionally, differences between pollution patterns are revealed, which suggest different contamination processes and entries. An ecosystemic approach of assessment is achieved by simultaneous consideration of different xenobiotics.     

Bestimmung und Bewertung adverser Effekte von Industriechemikalien im Umweltkompartiment Boden

The assessment of adverse effects in terrestrial ecosystems is of central importance to any Environmental Risk Assessment of Industrial Chemicals at an EU level. A conceptual proposal in this regard is clearly outlined in the ‘Technical Guidance Document’ which is currently undergoing revision; nonetheless, from an industrial point of view, there are still some unresolved questions: The design of ecotoxicological tests should not focus exclusively on reproducibility under defined laboratory conditions; of equal if not greater importance is the ecological relevance of tests, i.e. the ability of a (chronic) test system to adequately reflect substance-related effects on wild species at the population level. In readily biodegradable substances in particular, the choice of an appropriate test substrate and an optimized feeding regime as well as the analytical confirmation of nominal test concentrations is vital. Bioaccumulation of industrial chemicals in soil-dwelling organisms usually takes place via the pore water phase. Oligochaete worms such as Eisenia and Lumbricus have proven to be promising candidates for an experimental approach. However, there is still an urgent need for the development of a balanced understanding of how to evaluate the results of those studies. Variability is inherently high in terrestrial systems, making any differentiation between natural fluctuations of parameters and substance-induced effects on the structures and functions of ecosystems a difficult task. In order to strengthen their predictive value for population or ecosystem-related effects, any experimental study has to fulfill specific quality criteria (e.g. acknowledged test procedure; Good Laboratory Practice; appropriate methodological approach (including statistics); meaningful endpoints; clear linkage of results and experimental design). Only if these criteria are met can test results be used for regulatory purposes.     

In vitro-Screening von Gefahrstoffen in der Arbeits- und Umweltmedizin

Chromium, especially the metal and its trivalent and hexavalent compounds, are of great industrial interest. As a matter of fact, chromium workers have an occupational risk. While trivalent chromium compounds are of low toxicity, the hexavalent compounds are strong oxidants which cause not only a direct tissue damage (=acute toxicity), but also possess a carcinogenic, mutagenic and teratogenic potential (=chronic toxicity). Since the kidney is the main target organ after oral and/or dermal uptake of hexavalent chromium is the kidney, tubular necrosis might be the result of an acute toxification. This report presents anin vitro assay with cultured renal epithelial cells which allows the evaluation of the acute toxicity not only of trivalent and hexavalent chromium compounds, but also of various hazardous substances used in industrial production process. As shown here, an acute toxic effect was not detectable for the trivalent chromium (chromium (III)-chloridehexahydrate) within 24 h of exposure to concentrations as high as 200 μmol/l. In contrast, renal epithelial cells which were exposed to hexavalent chromium (potassium chromate) for the same time period exhibited marked signs of toxicity such as a rounding and detachment of the cells from the floor of the culture plates, an elongation and perinuclear development of vacuoles in the vital cells which were still attached, as well as a cells swelling and cellular fragments caused as a result of necrotic cell death and subsequent lysis. This toxic effect was already observed at concentrations above 5 μmol/l. In conclusion, thein vitro assay might be a good tool for the screening of hazardous substances in industrial medicine. More-over, by using additional tests, the chronic toxicity of such substances can also be examined. The selection of specific cell strains such as hepatocytes, neural cells etc. also allows the evaluation of toxic effects in individual organs. Thein vitro assay can not only be applied for the investigation of basic mechanisms of toxification and detoxification of specific compounds, but also delivers a basis for the screening of the reactivity of individual hazardous substances. Finally, the assay would allow a reduction in animal experiments as well as the simultaneous testing of a reactivity to multiple, hazardous substances.     

Die Bedeutung des organischen Kohlenstoffs im Unterboden

The organic carbon distribution among holorganic, topsoil, and subsoil horizons was determined for a series of 103 forest soils. The results show that only 25% and 36% of total organic carbon are stored within holorganic layers and topsoil, respectively. Subsoil was found to be the most significant compartment representing 39% of the carbon pool. This kind of distribution emphasizes the great importance of future research on structure and stability of subsoil organic carbon.     

Zur Problematik der Anwendung von Hintergrundwerten beim Vollzug des Bodenschutzrechts

The knowledge about background levels of heavy metals in soils is essential for the use of the precautionary values for heavy metals as provided by the German Soil-Protection-Act. In the northeast of Bavaria the 90th percentiles in the back-ground levels of heavy metals in the soil exceed the precautionary values in many cases. Background levels were determined separately for soils of different parent materials of rocks, soil horizons and land use (agricultural or forest soils), with the parent material of rock having the strongest influence on the content of heavy metals in different soils. Precautionary values are highly exceeded by chrome and nickel in basic and ultrabasic rocks. High variability of heavy metal contents was found even in soils of the same parent material (C-horizons), which is due to the natural geochemical variability of rocks and the mixing of different parent materials during the Pleistocene. For an effective use of the German Soil-Protection-Order, areas must be defined where the probability is high that the 90th percentiles of the background levels of heavy metals exceed the precautionary values. It has to be determined, how the risk of mobilisation of heavy metals can be estimated within these areas and what has to be done if heavy metal contents in soils exceed not only the precautionary values but also the background levels.     

Blei- und Cadmiumbelastung Zähne als Indikatoren der Blei- und Cadmiumbelastung des Menschen

The levels of lead and cadmium were determined in deciduous teeth of children from different areas of Northrhine-Westfalia, Germany. The children were born in 1968–1973 and 1979–1986. The levels of lead and cadmium in deciduous teeth show a significant decrease within this time interval. Lead decreases about 50 %, cadmium about 60 %. Since tooth lead and tooth cadmium may be used as indicators of the lead and cadmium body burden, the results of this study indicate a significant decrease of population exposure to lead and cadmium in West-Germany during the past 20–25 years, which is a consequence of pollution control and the increasing use of unleaded fuel.