Toxizitätsänderungen in Photoreaktionen von Azaarenen

The azaarenes and the structurally analogous PAH accompany each other and occur ubiquitously in nature. Photochemical conversions like direct photolysis or the photoreaction with nitrate are important natural degradation reactions of azaarenes. Furthermore, photoreactions with chlorine and bromine radicals can be expected in nature. The reactions generate a large number of oxidized, nitrated and halogenated products with unknown toxicity. In this paper, a first screening of changes is reported in acute toxicity during the course of the photochemical reactions. As test system luminescent bacteria are used. For quinoline, isoquinoline and phthalazine the investigations show different changes of the toxicity of the reaction mixtures in dependence on the respective reaction type. The toxicity of the reaction mixtures of quinazoline and quinoxaline increases in all reactions investigated. Furthermore the reactions of bromine radicals with azaarenes also show an increase of the toxicity in all cases. Compared with the azaarenes in all reactions products with significantly higher toxicity are formed.     

GIS-basierte Modellierung von Gewässerimmissionen

Goal and Scope

Environmental assessment of aquatic micro pollutants should consider the spatial and temporal variability of emission, transport and transformation. Simulation models coupled with Geographic Information Systems (GIS) provide digital maps of concentration patterns caused by the overlay of multipoint and diffuse emissions and natural attenuation processes in river basins. The paper gives an overview on GIS-based models for river basins and demonstrates the applicability by using some illustrating examples with GREAT-ER.

Main Features

Georeferenced models have several advantages: visualization of concentration patterns, investigation of spatial and temporal concentration profiles, analysis of exceedance of environmental quality standards, embedding in integrated river basin management systems.

Results and Discussion

GIS-based models allow a more realistic assessment. Monitoring programmes should be designed to deliver appropriate measured data for the evaluation and improvement of models.

Recommendation and Perspectives

The combination of digital maps, simulation models and environmental monitoring would provide better approaches for the risk assessment and water quality management of aquatic micro pollutants.     

Bioassay zur Bestimmung von TCDD-Toxizitätsäquivalenten (TEQ) von Umweltproben und Reststoffen

Polychlorinated aromatic hydrocarbons (HAH) like 2,3,7,8-tetrachloro-p-dioxin (TCDD) elicit a multitude of toxic and biological effects. A common trait of these substances is their affinity for a cytosolic receptor protein and the subsequent induction of the synthesis of several gene products, including cytochrome P450 1A1 (CYP 1A1). In this publication we present a bioassay to determine the induction of CYP 1A1 as a sum parameter for the total toxic potential of critical halogenated compounds in complex environmental matrices. In order to eliminate compounds like polycyclic aromatic hydrocarbons (PAH) and naturally occurring substances which might interfere with the bioassay we developed a simple cleanup procedure. TEQ values derived from bioassay are in good agreement with those obtained from chemical analysis. This bioassay in combination with the simplified “single column” clean up represents a cost and time effective alternative to chemical analysis for the screening of large numbers of environmental matrices.     

Minderung von Lärmimmissionen des Kfz-Verkehrs

Although the permissible emission limits for new motor vehicles are continuously being reduced year after year, the proportion of citizens in the Federal Republic of Germany who are affected by such traffic noise continues to remain practically constant. Thus, aside from the innovations in motor-vehicle technology, the question must be raised concerning what other possibilities are actually available for achieving a reduction in the emission of traffic noises. In the following, planning possibilities are presented for the traffic routes themselves and for their direct vicinities. An evaluation is also made concerning their efficiency. In addition to the prognostic tools of the guidelines which have been introduced in Germany and Austria, the application of modern research must also be taken into consideration.     

Bewertung der Umweltgefährlichkeit von Stoffen

By sending a questionnaire to all companies of the pulp and paper, textile finishing and leather industries in Germany a study ascertained wastewater data concerning the general situation, treatment processes and specific amounts. With these data standard figures used in the EU for the assessment of chemical substances were checked. The volume flows of the industrial sewage treatment were determined for the facilities of all three branches which discharge their wastewater directly to the receiving waters. The 10 percentile score of these facilities amounted to only a quarter of the EU standard figure of 2,000 m³/d. This value is related to a standardised waste water treatment plant within the EU, which treated the wastewater of 200 l/d from 10,000 inhabitants. The analyses of the entire branch in each case yield dilution factors of 20–70% of the EU standard value of 10. Only the full tanning leather companies yielded a dilution factor of 10. The volume flows of the sewage treatment plants of the facilities discharging to the sewer system exceeds 2,000 m³/d in call cases.     

Stabilitätsverhalten von ausgewählten anorganischen Spurenstoffen in Niederschlagsproben

The stability of H⁺, NH ₄ ⁺ , and PO ₄ ^3? ions in rainwater samples was in vestigated under different conditions cf storage and transport. Microbiological and physicochemical processes account for changes. Suppression of microbiological activities in deposition networks using conventional analyses may be achieved by adding AgCl-powder and by cooling to +4 °C.     

Bakterielle Biotestverfahren zur Bestimmung der Toxizität von Abfällen

For a risk assessment of wastes, fast and sensitive screening methods are required to detect possible toxic effects. In this study, different leachability methods (DIN 38414, part 4; EPA 1310; EPA 1320) were used to prepare aqueous leachates from different wastes; these leachates were rested in different bacterial toxicity test systems for possible toxic effects. As bacterial toxicity tests, the luminescent bacteria test and the growth inhibition test with activated sludge bacteria were used. The test systems showed a good agreement of the results from the different leaching methods, thereby indicating the reliability of the test systems used. The luminescent bacteria inhibition test showed a higher sensitivity than the growth inhibition test which is in good accordance with literature data. We conclude that both test systems are well suited to assess the toxic potential of aqueous waste leachates.     

Ökotoxikologische Wirkungen von Teeröl-imprägnierten Holzpfählen

Aim and Scope

This study was aimed at evaluating environmental effects of tar-oil impregnated (tanalized) tree stakes using simple and efficient biotests to obtain results of its ecological impacts during the tar-oil breakdown in the stake.

Results

1. Soil respiration was measured in-situ as an indication of soil microbial activity in two field trials. Soil respiration was measured in a 20 year-old apple orchard at various distances from the tar-oil impregnated tree stakes and also on soil mixed with chippings from pine stakes with tar-oil impregnation of different ages.
2. Cress germination tests were employed to evaluate tar-oil phytotoxicity in a field and laboratory trial. Cress was seeded close to tree stakes in the same 20 year-old apple orchard and germination rates related to tar oil-impregnation. Cress was also seeded in trays in sand mixed with pine chippings from stakes with tar-oil impregnation of different ages.
3. The portion of the carcinogenic benzoapyrene (BaP) ranged between 0.0015% in freshly tar-oil impregnated to 0.4% in tar-oil impregnated 20-year old trees stakes, i.e. irrespective of the overall PAK concentration and its degradation.
4. Kinetic analysis using DIXON plots showed a 50% breakdown of overall PAHs after ca. 2.7 years, i.e. km or Ki values of less than 3 years.

Conclusion

Germination tests of cress and endogenous seeds as well as soil respiration proved sensible indicators of the phytotoxicity and ecotoxicity of tar-oil impregnated tree stakes in fruit orchards. Soil respiration proved particularly sensitive to tar-oil ageing. Its combination with kinetic inhibition models resulted in parameters suitable for the interpretation of results.     

Schnelle Elementanalytik zur Abschätzung von Dioxinbelastungen: Ein neues Werkzeug zur Untersuchung von Brandschäden?

A car and a railway coach with an InterCityExpress interior were combusted in a tunnel. The deposition of pollutants could be detected by passive sampling devices over the distance of several hundred meters. Cotton passive collectors were analyzed for the elements Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Sb, Sn, V and Zn. A comparison with analytical results of PCDD/F and PAH (US EPA) showed a close similarity between the concentration profiles of some elements and the organic pollutants. As one outcome, Cd, Cu, Pb, Sb, Sn and Zn could be used as indicators for the estimation of surface contamination with PCDD/F or PAH in the event of such fires, thereby providing the advantages of faster results and lower costs.     

Biomonitoring von organischen Luftschadstoffen mit Pflanzenblättern

In the paper some remarks concerning results in biomonitoring of organic air pollutants with plants are made. Temperature dependent sorption and concentration effects are the two most important factors leading to difficulties in data interpretation and comparing different studies. Using results of various studies in which the PAH accumulation in plants was investigated some conclusions are drawn and recommendations are made for the further study and use of plants as biomonitors.     

Photometrische Bestimmung der Zytotoxizität von Chemikalien

Two test methods are presented to assess the cytotoxicity of chemicals. On one hand the protozoonTetrahymena pyriformis and on the other the bacteriumPseudomonas aeruginosa is cultured in defined media containing the test chemicals. Test parameter is the quantity of living cells surviving exposure. The conversion of the tetrazolium salt MTT into formazan is equivalent to cell viability. A mixture of detergent and isopropanol is used to dissolve the blue formazan which is not soluble in water, prior to photometric measurement. For cetyltrimethylammonium bromide, benzyldimethyldodecylammonium chloride, dodecylbenzenesulfonic acid sodium salt, potassium dichromate, 4-toluenesulfonic acid sodium salt, and 4-nitrophenol the EC50-values (mol/l) in theTetrahymena pyriformis- (Pseudomonas aeruginosa) test system were: 10^?5,81 (10^?5,08); 10^?4,68) (10^?3,80; 10^?4,50 (10^?4,14); 10^?3,97 (10^?5,11); 10^?2,71 (10^?2,50) and 10^?4,00 (10^?3,64). — With the assays described here it is possible to measure a large number of samples by quick and simple means.     

Abschätzung der Einträge von polyzyklischen aromatischen Kohlenwasserstoffen in deutsche Gewässer

Background, aim, and scope Polycyclic aromatic hydrocarbons (PAH) result from incomplete combustion of almost every organic materials, e.?g. due to forest fires, residential heating, combustion engines, grilling, or smoking. PAH are predominantly distributed over the air-path. Their usage in products (e.?g. moth-balls) has been limited strictly or completely forbidden in the past. In the context of the EU Water Framework Directive (WFD), the single substances anthracene, fluoranthene and naphthalene, as well as PAHs as group of substances, are listed as “priority” substances. Background of this work is a first compilation of sources of PAH emissions, and in this context, the collection of all relevant data and information to calculate the total emissions into surface waters in Germany. Materials and methods Within the scope of diverse research projects, funded by the German Environmental Agency, the available data material concerning PAH input in surface waters has been analyzed by the Fraunhofer Institute for Systems and Innovation Research. On the basis of the collected data, a first evaluation of relevance of the different sources has been conducted using the model MONERIS. Results As a result of the atmospheric deposition, PAHs enter, to a large extent, surface waters directly or indirectly through surface runoff (e.?g. urban areas, wastewater treatment plants, erosion). Discussion Although there is still additional research need for some of the covered PAH sources, a noticeable distribution pattern of relevance emerges. Conclusions The scenarios, based on the currently known sources, show that the implementation or the neglect of emission reduction measures in the field of diffuse air-borne PAHs are crucial for the further development of the deposition of PAHs in surface waters. More far-reaching studies are necessary, e.?g. concerning emissions from inland navigation/motor boats, the inhomogeneous source “products”, or the path “erosion”. Recommendations and perspectives According to the EU-WFD, all depositions, emissions and losses of “priority hazardous” classified substances, such as the group of PAHs, have to be stopped or gradually finished in the long term. Until the year 2015, environmental quality standards (EQS) have to be met for all “priority substances”. Presently, the EQS often are not completely fulfilled for many substances of the PAH group, including benzo(a)pyrene. Reduction measures are necessary within diverse areas, especially concerning diffuse atmospheric emissions (e.?g. “residential heating”).     

Untersuchung von Abfällen mit biologischen Testverfahren zur Bewertung der Wassergefährdung

Wastes from three different types of waste treatment facilities (slag from a municipal waste incineration plant, slag granules from a pilot plant combining carbonization and incineration, mechanical and biological treated wastes) were examined to determine their hazard potential to different waters sites. The process temperature is seen to be the main difference between the three treatment processes. The wastes were extracted with water according to the German standard DIN 38414 S 4 and additionally at a constant pH value of 4. The leachates were investigated in a battery of aquatic bioassays and characterised physically and chemically. Every leachate revealed in a toxic effect at least in one test. The toxicity of the leachates prepared at a pH of 4 was significantly higher than the toxicity of the leachates prepared by extraction with water without pH adjustment. The leachates of the slag granules showed the lowest toxicity. On the basis of these experimental results, a scheme to derive Water Hazard Classes of wastes, which is presented in part II of this publication, was developed.     

Bewertung der potenziellen Grundwasserbelastung von deponierten Hochofengasschlämmen

Goal and Scope

Blast-furnace sludge is a waste originating from pig-iron production and contains contaminants such as lead, zinc, fluoride and cyanide assumably contaminating the groundwater by leaching.

Methods

We investigated the chemical composition of 27 samples of landfilled blast-furnace sludge in pore waters which were obtained by the centrifugation of fresh material and elution with water according to DIN 38414 part 4 (S 4).

Results

The pore waters as well as the eluates were neutral to alkaline (pH 7.3 to 10.7) and were dominated by alkali and alkaline-earth metals as well as sulphate and nitrate. The concentrations of all elements and compounds investigated were mostly clearly larger in the pore waters than in the eluates. The average concentrations of environmentally relevant constituents such as lead (0,18 mg?1), zinc (1,5 mg l?1), fluoride (10,6 mg l?1), and total cyanide (1.8 mg l?1) in the pore waters were distinctly larger than the inspection value of the German Federal soil Protection Ordinance for the pathway soil-groundwater. Lead, zinc, and total cyanide concentrations in the pore waters were largely underestimated by the eluates, as these concentrations were 70 to 90% lower in the eluates compared to the pore waters.

Conclusion

In the case of landfilled blast-furnace sludge, eluates according to DIN 38414 part 4 (S 4) provide low concentrations which are unrealistic to forecast concentrations in the seepage water.     

Auftreten von PCDD/PCDF in Brandfällen

Over the last years, polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/PCDF) have been identified in the soot of various accidental fires at concentrations which have made an extensive reconstruction of the buildings necessary. In these cases, dioxin precursors like polychlorinated biphenyls (PCB) or large amounts of other halogenated organic compounds like PCV cable coatings were involved. Dependent on the circumstances of the fire and the materials burnt, the levels of contamination and the congener pattern of the PCDD/PCDF in the soot were different. The analytical results from various accidental fires were evaluated and compared with laboratory data. A hierarchical cluster analysis supports the interpretation of the data and shows that the contamination of the soot from the fire in the Düsseldorf Airport in April 1996 was a mixed contamination primarily caused by PCB and PVC.     

Untersuchung von Abfällen mit biologischen Testverfahren zur Bewertung der Wassergefährdung

Wastes from three different types of waste treatment facilities were examined with bioassays to determine their hazard potential to waters (→Part I). All examined wastes showed toxic effects and have to be classified as hazardous to waters according to section 19g of the German Federal Water Management Act. The toxicity is probably caused by heavy metals in the leachates, especially copper. An evaluation pattern to classify wastes in the German system of Water Hazard Classes is presented. According to this proposal, a classification of the examined wastes into Water Hazard Class 1 seems to be appropriate. This classification does not describe the hazards resulting from the regular disposal on a landfill or from the utilisation of the treated wastes.     

Verteilung und Abnahme von bodennahem Ozon in städtischen und ländlichen Regionen

The compilation of ozone data for the federal states of Hesse and Northrhine-Westphalia (NRW) in Germany indicated that the concentration of ozone level slightly decreased during the years 1990–1998. The average concentration of ozone over forest areas is significantly higher than over cities. Only the maximum figures in the years approached one another. However, values passing the legal thresholds (180 μg ozone/m³) were two to three-fold higher over forests than over cities. The ozone concentration in air is inversely proportional to the traffic density. It is suggested that the lower NOx concentration over the forest than over cities is involved in the maintenance of the higher ozone-concentration over forest areas. In the cities, the ozone is reduced by NO to almost zero at night, whereas it is reduced by only about 50% over forests with lower NO concentrations. This reduction is only partially compensated in connection with the photolysis of NO₂ and the subsequent oxidation of O₂ to O₃ during the day. The ozone situation is principally the same in the federal states of Hesse and Northrhine-Westphalia.