The use of respirometric measurements to determine the toxicity of textile dyes in aqueous solution and after oxidative decolourisation processes

Selected results from the degradation of reactive-dye hydrolysates after UV irradiation, ozonation and sodium peroxodisulphate (NaPS) treatment are presented. Reactive dyes with representative chromophores and anchor groups were chosen for the research project. Different stages of oxidative decolourisation were examined and determined by water parameters for biological degradation (BOD). The paper focuses on toxicity tests with Pseudomonas putida to consider whether the oxidative treatments result in products with a risk for the environment. Tests were performed with the AQUALYTIC^® Sensomat System, which measures biological oxygen demand (BOD). It was determined that the chosen oxidative treatments had as a rule no bearing on respiration of P. putida. Experiments with hydrolysates after short-term UV irradiation resulted in a slightly increased but not long-lasting toxicity in comparison with treatments with ozone or NaPS. Toxic effects were found in tests with hydrolysates of metalliferous dyes. During oxidative treatment, metals were liberated from the chromophores. This did cause complete inhibition of respiration of P. putida. Dye Blue E, a member of a dye class with chlorotriazine anchor groups, was itself found to be toxic, caused by the reactivity of the anchor group. The hydrolysate is only of minor toxicity.     

Determination of selected microbial volatile organic compounds by diffusive sampling and dual-column capillary GC-FID--a new feasible approach for the detection of an exposure to indoor mould fungi?

A new, analytically valid procedure is described to assess the exposure of human beings to the so-called microbial volatile organic compounds (MVOCs) in air. The method can be used routinely for large sample numbers and is especially valuable as a basis for further research on the correlation between single MVOCs and indoor mould growth. The procedure is based on the fact that fungi produce a variety of volatile organic compounds, such as 3-methylbutan-1-ol, 3-methylbutan-2-ol, fenchone, heptan-2-one, hexan-2-one, octan-3-one, octan-3-ol, pentan-2-ol, alpha-terpineol, and thujopsene, which they emit into the indoor environment. Using diffusive samplers, these MVOCs are adsorbed onto charcoal during a sampling interval of four weeks. The described method is thus superior to existing methods which use short-term active sampling. After desorption with carbon disulfide, the MVOCs were determined by dual-column gas chromatography with flame ionization detection using the large-volume injection technique for sample introduction. The detection limits ranged between 0.15 and 0.53 microgram m-3, within-series precision was found to range between 6.5 and 19.0%, and recovery was between 77 and 118%. The procedure has been successfully applied in the context of a large field study to measure the indoor MVOC exposure in children's rooms of 132 dwellings. The objective of the study was to examine the relation between indoor mould growth, the indoor MVOC exposure and the prevalence of adverse health effects. Information about mould formation has been obtained by a questionnaire and by the determination of colony forming units of mould fungi in mattress dust. With the exception of 3-methylbutan-2-ol, fenchone, nonan-2-one, octan-2-one, and thujopsene, indoor air concentrations of all MVOCs under investigation were significantly higher inside damp and mouldy dwellings. From the primary MVOCs under investigation, 3-methylbutan-1-ol, hexan-2-one, heptan-2-one, and octan-3-ol were found to be most reliable indicators for mould formation. A correlation was also found between selected MVOCs and the occurrence of mould species in mattress dust. Aspergillus sp. correlated with heptan-2-one, hexan-2-one, octan-3-ol, octan-3-one, and alpha-terpineol, while the occurrence of Eurotium sp. was correlated with higher indoor air concentrations of 3-methylbutan-1-ol, 3-methylbutan-2-ol, heptan-2-one, hexan-2-one, octan-3-ol, and thujopsene. Children living in dwellings with elevated MVOC levels had a higher prevalence of asthma, hay fever, wheezing, and irritations of the eyes. These positive associations persisted after controlling for confounding factors such as age, sex, body-mass index, number of siblings, social status, passive smoking, type of heating, and ventilation habits. However, they were not statistically significant. This lack of significance may be a result of the small number of investigated samples.     

Ecological Sanitation--a way to solve global sanitation problems?

Today about 2.4 billion people in rural and urban areas do not have access to adequate sanitation services. Within 20 years, it is expected that an additional 2 billion will live in towns and cities, mainly in developing countries, demanding sanitation. Still over 90% of sewage in developing countries is discharged untreated, polluting rivers, lakes and coastal areas. Conventional sanitation concepts, based on flush toilets, a water wasting technology, are neither an ecological nor economical solution in both industrialized and developing countries. The water-based sewage systems were designed and built on the premises that human excreta are a waste; suitable only for disposal and that the environment is capable of assimilating this waste. A sanitation system that provides Ecological Sanitation (EcoSan) is a cycle--a sustainable, closed-loop system, which closes the gap between sanitation and agriculture. The EcoSan approach is resource minded and represents a holistic concept towards ecologically and economically sound sanitation. The underlying aim is to close (local) nutrient and water cycles with as less expenditure on material and energy as possible to contribute to a sustainable development. Human excreta are treated as a resource and are usually processed on-site and then treated off-site. The nutrients contained in excreta are then recycled by using them, e.g., in agriculture. EcoSan is a systemic approach and an attitude; single technologies are only means to an end and may range from near-natural wastewater treatment techniques to compost toilets, simple household installations to complex, mainly decentralised systems. These technologies are not ecological per se but only in relation to the observed environment. They are picked from the whole range of available conventional, modern and traditional technical options, combining them to EcoSan systems. The paper presents an introduction to EcoSan principles and concepts including re-use aspects (available nutrients and occurring risks), and case studies of EcoSan concepts in both industrialized and developing countries.     

Soil microarthropods (Acari,Collembola) from beach and dune: characteristics and ecosystem context

Soil microarthropods (Acari, Collembola) were analyzed along transects from shore to brown dune in two sandy coastal sites of the North Sea (Jutland, Denmark, and Spiekeroog, East Frisian island, Germany). Predatory mites (Acari: Gamasina) and Collembola were determined to species. The Jutland and the Spiekeroog sites each yielded 22 Gamasina species, 10 of which are common to both areas. Collembola were identified from the Spiekeroog samples only (also 22 species). Largest mite abundances were found in Jutland in primary dunes (419 tsd. ind./m²) and on Spiekeroog in old brown dunes (314 tsd.ind./m²). Compared to the mites, Collembola abundances are low, with maxima of 77 tsd.ind./m² in Jutland (yellow dune) and only 18 tsd. ind./m² on Spiekeroog (old vellow dune). The communities of predatory mites (Gamasina) and Collembola along transects from shore inland to brown dune are quite specific. High similarities are found for the predatory mites between the specific dune sites of the two North Sea areas, particularly for yellow dune. Additionally, preliminary data are presented for the southern Baltic Coast. The findigns are discussed in a broader context. Arguments focus on conservation and biogenic dune stabilization.     

Multi-scale scenarios of spatial-temporal dynamics in the European livestock sector

The European livestock sector has changed rapidly in the recent past and further changes are expected in the near future due to reforms in the European Common Agricultural Policy (CAP), increasing environmental concerns and changing consumer awareness. We developed a multi-scale modeling approach for exploring spatial and temporal dynamics of livestock distribution by accounting for drivers at different spatial scales. Such approach can provide a basis for environmental impact assessments of livestock farming at broad spatial scales. Assessment of change in both quantity and location was made for six livestock types. Four contrasting scenarios were applied ranging from globalization to regionalization, as well as from low regulation levels and dominance of market forces towards a higher degree of governmental regulation. National level livestock numbers as calculated by a macro-economic model were spatially distributed at the landscape scale according to the scenario assumptions considering biophysical, socio-economic, and political forces. Results indicate for most of the old European Union (EU) member countries a decrease in livestock numbers. In the new EU member countries sheep, goats and pigs are expected to decline while beef cattle and poultry are expected to grow. Livestock densities are expected to increase both within and outside current livestock hotspot regions in absence of environmental legislations. Environmental pressure as result of high livestock densities may, however, also remain in regulated scenarios where environmental policies are implemented and income support remains stable over time due to path dependencies in the livestock sector. But contrary to the non-regulated scenario it is less likely that new areas with high risk of negative environmental impacts due to livestock farming will develop.     

Sociogenetic structure in a free-living nocturnal primate population: sex-specific differences in the grey mouse lemur (Microcebus murinus)

The grey mouse lemur (Microcebus murinus) has a dispersed social structure, within which female sleeping associations are common. These sleeping associations have been hypothesised to confer anti-predatory and thermoregulatory benefits, especially when rearing offspring. The genetic composition of these associations was determined using microsatellite markers to test predictions derived from kin selection theory. 161 (99 males, 62 females) individual M. murinus belonging to a free-living population in Ampijoroa, north-western Madagascar, were genotyped and observed over a total of 13 months distributed over the dry seasons of 3 successive years (1995-1997). Kin selection theory predicts that these female associations should consist of closely related members, and that female philopatry and male natal dispersal should characterise the dispersal pattern within this species. These predictions were confirmed by the data. Five out of six female sleeping groups consisted of one or more closely related dyads. Females that slept alone did not have close female kin in the vicinity or within the population at all. Closely related female dyads lived in significantly closer proximity than closely related male dyads and closely related male-female dyads showed intermediate proximity. In combination with the result that females possessed significantly more relatives within the population than males, these findings support the behavioural hypotheses of female philopatry and male natal dispersal. Matrilinear grouping patterns and sex-biased dispersal are therefore genetically established in a dispersed primate social organisation for the first time. The results further indicate that several generations of mouse lemurs live together within a given area, implying both an effective mechanism of kin recognition to avoid father-daughter incest and the potential for social learning to ensure individual recognition.     

Geese and dietary allelochemicals — food palatability and geophagy

Summary The palatability of plants was studied in young, immature and adult geese of three species,Anser anser, Anser indicus andBranta canadensis, with respect to secondary plant metabolites. In their first 1–4 weeks of life, hand-reared goslings feed on a wide variety of plants, more or less irrespective of their allelochemical contents. Older birds become more selective, but still consume plants which are normally considered to be unpalatable or even toxic for other animals. Choice experiments were performed with pure secondary metabolites which were offered on otherwise highly palatable food items, such as leaves ofTaraxacum officinale. These experiments revealed a similar trend, in that very young goslings discriminate their food much less than older goslings or adult geese. In general, food contaminated with essential oils was rejected, whereas alkaloids, glycosides, amines and sulfur compounds were tolerated to a remarkable degree. In consequence, especially young, but also adult geese must have a high capacity to tolerate and/or to detoxify dietary allelochemicals. Another detoxification mechanism became evident during the experiments: geese ingest soil and mud quite regularly. It could be shown experimentally that the respective soil had a high capacity to bind alkaloids. We assume that geophagy is a means (besides a presumed active detoxification in the liver) to adsorb and thus reduce the contents of dietary allelochemicals.