Tradescantia micronucleus test indicates genotoxic potential of traffic emissions in European cities

Urban atmospheres contain complex mixtures of air pollutants including mutagenic and carcinogenic substances such as benzene, diesel soot, heavy metals and polycyclic aromatic hydrocarbons. In the frame of a European network for the assessment of air quality by the use of bioindicator plants, the Tradescantia micronucleus (Trad-MCN) test was applied to examine the genotoxicity of urban air pollution. Cuttings of Tradescantia clone #4430 were exposed to ambient air at 65 monitoring sites in 10 conurbations employing a standardised methodology. The tests revealed an elevated genotoxic potential mainly at those urban sites which were exposed to severe car traffic emissions. This bioassay proved to be a suitable tool to detect local 'hot spots' of mutagenic air pollution in urban areas. For its use in routine monitoring programmes, however, further standardisation of cultivation and exposure techniques is recommended in order to reduce the variability of results due to varying environmental conditions.     

Ökologische Kriterien der Technik- und Stoffbewertung: Integration des Vorsorgeprinzips

The development of criteria for the comparative assessment of technologies and substances beyond the toxicological approach and the development of an integrated pattern of criteria is still at the beginning. The criteria presented here for integrating the precautionary principle into the substance and technology assessment have to be further operationlised and completed, in the same way as the criteria which have been discussed and developed within the framework of

- the poisoning and pollutant paradigm

- the equilibrium paradigm

- the sustainability and “Mitwelt” paradigm

- the energy and the general technology assessment debate.

The resolution of the criteria has to be improved and their range (which is certainly limited) has to be explored more precisely. The application of the criteria should never occur mechanically. Technology assessment and substance assessment are not only scientific, but essentially social and, hence, discursive processes. It is not so much the assessment of individual substances which should be in the center of the debate, but rather the comparative assessment of competing techniques, substances and substancerelated development pathways (see vonGleich andRubik, 1966 as a first approach to assess the environmental effects of old and new materials). According to the example of the energy strategies, only the development of competing strategies in the substance field could create the necessary prerequisites for a broad public discourse and thus for a democratisation of the basic substancerelated policy decisions. This discourse is a duty which science and economy have toward society.     

Eine Apparatur zur kontinuierlichen Respirationsmessung an marinen Organismen

Measurements were made with a Clark electrode in a closed system under conditions of different, regulatable water current velocities. Six simultaneous parallel measurements are possible with only one electrode. The volume of respiration chambers amounts to 80 ml for small animals and 300 ml for larger ones. Technical details of the apparatus and measuring procedures are described. The accuracy amounts to 0.5 μl O₂ for the 80 ml chamber, and 2 μl O₂ for the 300 ml chambers. The apparatus has been successfully used on various marine evertebrates and algae.     

Die ökologische Bewertung von Seeufern in Deutschland

Goal and Scope

Details about the ecological function of lake shores as ecotones between land and lakes are not well-known. These ecotones are also heavily exploited and, in part, considerably changed. Whereas anthropogenic nutrient loading is decreasing, structural changes are increasing. Unfortunately, there is a deficit in methods of evaluation and decision processes.

Main Focus

Even the EU-water framework directive was no remedy for this deficit, as lake shores were included only implicitly. In this article several evaluation methods and their conceptual groundwork are presented. However, these methods were not developed for lake shore research. Therefore, criteria are proposed which could fulfill the specific demands of lake shore assessments. The management of lakes shores should consider structural and biological parameters, and be agreeable to local residents.

Results and Conclusions

In addition to conventional biodiversity methods, the ecology of lake shores could also be represented by a functional food net, for example in benthic invertebrates. But even quantification of biodiversity alone creates many problems. A simple biodiversity index cannot meet all the demands placed on a method of evaluation in complex situations, especially when coupled with additional information on structure, practicability, costs, etc. For these reasons, assessments for future management cannot be based on such an index.

Outlook

A possible approach to include this complexity in assessments is to apply mathematical models and theoretical order concepts.     

Abwasserbehandlung beim kontrollierten Rückbau einer Pflanzenschutzmittelfabrik

During the demolition of an industrial building contaminated with chlorophenols and polychlorinated dibenzodioxins (from Boehringer & Sohn in Hamburg-Moorfleet, Germany), several measures must be taken in order to protect the surroundings. Since these compounds are strongly adsorbed by particulate matter, a mist is continuously sprayed over the whole building. The waste water is expected to be highly contaminated and must therefore undergo extensive purification procedures. The primary goal of the existing study is to examine whether or not the present effluent reprocessing unit, a system which is comprised of a charcoal filter, is able to clean the waste water according to legal requirements. Secondly, the main factors that influence the clean up of the effluent were investigated in order to design a suitable precleaning unit for the contaminated water should the present reprocessing unit not fulfill these requirements. By means of the factorial design technique, the effect of three factors (flow velocity of the water, amount of charcoal and the pH-value) on the efficiency of the cleaning process and with regard to chlorophenols was examined. Surprisingly, the pH-value does not have a significant effect on the efficiency. In addition, the results of the experiments show that a precleaning of the effluent is not required.     

Analytische Schnellerkennungsmethoden: Bewertung abzulagernder Abfälle und Kontrolle von Deponien

Rapid test methods have been developed to classify waste. These procedures includes rapid elution and analytical determination methods for the detection of such elements as copper, nickel and zinc. Test kits for matter analysis (with a time requirement of about 30 minutes) have been modified with regard to the matrix waste. A comparison between such rapid testing methods and standard procedures using real samples leads to a similar waste classification. The reduction in time and costs via rapid assay methods allows multiple determinations of wastes to consequently increase the reliability of results from heterogeneous samples. The simple and rapid employment of these tests also makes an “on-site” performance possible.     

Estimating the complexity of bird song by using capture-recapture approaches from community ecology

Repertoire size, the number of unique song or syllable types in the repertoire, is a widely used measure of song complexity in birds, but it is difficult to calculate this exactly in species with large repertoires. A new method of repertoire size estimation applies species richness estimation procedures from community ecology, but such capture-recapture approaches have not been much tested. Here, we establish standardized sampling schemes and estimation procedures using capture-recapture models for syllable repertoires from 18 bird species, and suggest how these may be used to tackle problems of repertoire estimation. Different models, with different assumptions regarding the heterogeneity of the use of syllable types, performed best for different species with different song organizations. For most species, models assuming heterogeneous probability of occurrence of syllables (so-called detection probability) were selected due to the presence of both rare and frequent syllables. Capture-recapture estimates of syllable repertoire size from our small sample did not differ significantly from previous estimates using larger samples of count data. However, the enumeration of syllables in 15 songs yielded significantly lower estimates than previous reports. Hence, heterogeneity in detection probability of syllables should be addressed when estimating repertoire size. This is neglected using simple enumeration procedures, but is taken into account when repertoire size is estimated by appropriate capture-recapture models adjusted for species-specific song organization characteristics. We suggest that such approaches, in combination with standardized sampling, should be applied in species with potentially large repertoire size. On the other hand, in species with small repertoire size and homogenous syllable usage, enumerations may be satisfactory. Although researchers often use repertoire size as a measure of song complexity, listeners to songs are unlikely to count entire repertoires and they may rely on other cues, such as syllable detection probability.Communicated by A. Cockburn     

Does song reflect age and viability? A comparison between two populations of the great reed warbler Acrocephalus arundinaceus

Song complexity is often regarded as a sexually selected trait that reflects the overall quality of a male. In many passerine species, old males possess larger song repertoires than younger males. This may be either because individual males improve their performance as they get older (longitudinal increase) or because poor singers have reduced viability and, hence, are underrepresented in old age classes (cross-sectional increase). We studied the age dependence of repertoire size and other song traits in a German and a Swedish great reed warbler (Acrocephalus arundinaceus) population. We found marked differences between longitudinal and cross-sectional approaches, as well as between the two study populations. In the German population, we found that syllable switching, a measure of immediate versatility and strophe length, increased with age in a cross-sectional analysis. This was not because birds improved with age (longitudinally) but because syllable switching was positively correlated with male longevity. However, in Sweden, syllable switching seemed to be unrelated to age and longevity. In the Swedish population, individual males increased their repertoire size as they got older (longitudinal increase), but this did not happen in the German population. Hence, two populations, even when belonging to the same subspecies, may differ in whether or not they show delayed song maturation.