Ökotoxikologische Charakterisierung von Nonylphenol Isomeren

Background, Aim and Scope

Acute toxicity and estrogenic potency of six nonylphenol isomers, with nearly the same chemical structure and the same physico-chemical properties, were investigated in this study. Thes datasets give some insight into how far structure activity relationships can be used for these modes of action.

Methods

The toxicity of the isomers was investigated by the daphnia immobilisation test as well as the duckweed growth inhibition test. The estrogenic potency of the p-NP isomers was analyzed by MVLN-Reportergen-Assay.

Results

No differences between the isomers were found for baseline toxicity, neither in the daphnia immobilisation test nor in the duckweed growth inhibition test. Estrogenic potency of the isomers in the MVLN reportergen assay was markedly different for the tested isomers. The highest estrogenic potency was found for p353-NP, whereas p262-NP and p22-NP exhibited no estrogenic, but partial antagonistic potency in this assay.

Discussion

The results from this study clearly indicate how far simplification and structure activity relationships can be used in risk analysis. For bioconcentration and baseline toxicity structure activity relationships are possible and will allow simplification of the risk analysis. For special modes of action simple structure activity relationships are per se impossible. This was shown especially for the estrogen receptor interactions, where only small structural differences can lead to different modes of action.

Conclusions

It seems possible to reduce the effort for risk analysis, using combinations of measured data and predictive models. At the moment it seems unlikely that predictive models alone will and can be used for risk analysis.     

Echolocation behavior of the bat <Emphasis Type="Italic">Vespertilio murinus</Emphasis> reveals the border between the habitat types “edge” and “open space”

We test the hypothesis that echolocation behavior can be used to find the border between bat habitats. Assuming that bats react to background targets in “edge space” but not in “open space”, we determined the border between these two habitat types for commuting individuals of the parti-colored bat Vespertilio murinus. We recorded sequences of bats’ echolocation signals while they flew parallel to the walls of large buildings and to the ground and determined the signals’ average bandwidth, duration, and pulse interval. These parameters varied systematically with the estimated horizontal and vertical distances between the bats and the background. A distinct effect of horizontal distance to the background on echolocation behavior was found for horizontal distances of less than 6 m, thus indicating the border between edge and open space. Only a few bats flew at vertical distances below 5 m. However, enough passages at vertical distances of 5 m and above indicated that the vertical border is somewhere below a distance of 5 m. Within edge space, V. murinus reacted to the background by reducing signal duration, increasing bandwidth at closer distances, and often emitting one signal per wing beat. In open space, signal parameters did not vary as a function of distance to the background. There, V. murinus emitted the longest signals with the narrowest bandwidth and often made one or two wing beats without emitting a pulse. With our data we support with statistical methods the hypothesis that echolocation behavior reveals the border between the habitat types “edge” and “open space”.     

The value of the environment – Is it a matter of approach?

This paper discusses why estimates of the benefits of reduced air pollution differ in accordance with the approach used. Estimates based on bottom-up studies of the damage costs related to air pollution usually turn out much lower than estimates based on assessments of the utility of reduced air pollution, obtained for instance by willingness to pay assessments. This is usually explained by the fact that the willingness to pay approach includes the utility aspect of non-market values, and for this reason, it is often preferred to the damage cost approach. This is, however, not the whole story. The paper shows why alternative approaches should not be considered as being in conflict, but rather as means to get supplementary information necessary to put a value on environmental quality. Information from bottom-up assessments of damage costs and from studies of the willingness to pay is used in a macroeconomic model to carry out an evaluation of the social costs of energy saving measures in Hungary.     

Behaviour of Rice-Byproducts and Optimizing the Conditions for Production of High Performance Natural Fiber Polymer Composites

This present study deals with evaluating some available rice by-products, such as rice straw and rice husks, as a fiber component in manufacturing of high performance natural fiber polymer composites (NFPC). The utilization of these undesirable wastes will contribute to the reduction of the environmental impact of waste disposal by burning. Two matrices (thermoset and thermoplastic) were used. Optimization of manufacture conditions of polyester-based thermosetting polymer composites was carried out through examine the effects of fibers to polymer ratio, amounts of catalyzed and initiator, fraction size of fibers and substituting one fibers by another, as well as time, temperature and pressure of pressing. The possibility of styrene containing polyester solution on improving the fiber interface via in situ grafting and enhancing the strength and water resistance of the produced NFPC was also evaluated, in comparison with that produced from using thermoplastic matrix (polypropylene) in presence of coupling agent. The production of this valuable product (NFPC) by this simple procedure, which not needs special devices (twin extrusion with heater), and chemicals to improve the compatibility between fibers and polymer matrix, will ensure reasonable profits and direct impacts on the Egyptian economy in general and rice growers in particular.     

Acute exposure to chemicals during ‘do-it-yourself’ activities: survey of enquiries to the Swedish Poisons Information Centre in 1996

In 1996 the Swedish Poisons Information Centre performed a follow-up study concerning poisonings related to ‘do-it-yourself’ activities. The study was supported by the National Institute of Public Health in Sweden. The objectives were to investigate and define monthly variations, route of exposure, type of products and, in particular, exposures to corrosives, age and sex groups, place of treatment, severity of symptoms, place of the accident, special risk products and risk situations. The Poisons Information Centre was contacted concerning 1609 cases, with a peak during the summer months. There was no or uncertain connection between exposure and symptoms in 117 cases. This means that 1492 cases were left to study. Inhalation and eye exposure were the predominant routes, followed by skin exposure and ingestion. Cleaning agents were the most common type of products involved. Of the 1492 cases included in the study 1033 were possible to follow up. Among these, 20–29 year olds and 30–39 year olds predominated, and there was a dominance for men. In total, 28% of those exposed were subject to medical attention, either in hospital or in outpatient clinics. According to the Poisoning Severity Score 78% had mild (grade 1) and 7% moderate (grade 2) symptoms. There were no severe intoxications and no deaths. Severity grade 2 occurred 3.6 times more often among those with exposures involving risk of corrosive damage than among others in the study population. Most accidents occurred in the home. Special risk products and risk situations were exposure to corrosive products, release of chlorine when mixing hypochlorite and acid, ‘fire-eating’, siphoning gasoline and diesel fuel, welding, and inhalation of carbon monoxide from exhaust gases. The Swedish Poisons Information Centre registered 1609 cases of poisoning accidents during ‘do-it-yourself’ activities, which means an average of four to five cases per day. Although this type of accidents is not uncommon, significant poisoning seems to be rare. Some special risk situations were identified.     

Further experiments on olfactory navigation and non-olfactory pilotage by homing pigeons

Summary Supplementary to a previous investigation (Wallraff and Neumann 1989), further experiments were conducted with homing pigeons that were either familiar of unfamiliar with the release area, and that had or lacked olfactory access to environmental odours. All four possible pairwise combinations of these factors were tested. The previous results were confirmed, showing that in an unfamiliar area olfactory inputs are necessary for home-related orientation, while in a familiar area both olfactory and non-olfactory information can be utilized and each is more or less redundant as long as the other kind of information is also available. The degree of redundancy of olfactory inputs varies, obviously depending on the pattern of individual local experience. Correspondence to: H.G. Wallraff     

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.