Untersuchungskonzept zur Charakterisierung toxischer Stoffe in belastetem Wasser

Simple biotests are frequently used for the ecotoxicological assessment of waste water. Unfortunately, and not too rarely, effects are detected and the question concerning water-polluting substances has to be answered. The latter are enriched by solid phase extraction (SPE), then isolated and fractioned by thinlayer chromatography using automatic multiple development (AMD). One strip of the DC-plate is separated and used without further atterations for the biological detection with microorganisms (Bacillus subtilis, luminous bacteria). With this system, toxic bands can be identified. From the other part of the DC plate, an UV-spectrum can be taken of the toxic bands using a DC scanner. Subsequently, the corresponding bands are scratched out and the toxic substance is eluted and analysed with infrared spectroscopy. The infrared spectrum can be characterised by comparing it with reference spectra. In this submitted work, a concept is presented with an example of a “nipple rubber” eluate. It shows that this rubber article liberates a vulcanization accelerator, 2-mercaptobenzothiazole.     

The influence of south Foehn on the ozone distribution in the Alpine Rhine valley—results from the MAP field phase

During the Mesoscale Alpine Programme (MAP) special observation period (SOP) between 7 September and 15 November 1999, ground-based and airborne measurements have been conducted in the Rhine valley south of the Lake of Constance to investigate the unstationary aspects of Foehn and related phenomena, like the impact of Foehn on the ozone concentrations in the valley. Foehn events occurred with above-average frequency and high diversity. Foehn induced ozone peaks in October and November are found to be much lower than the September Foehn case of the period. An inversion layer in the lake area with ozone concentrations below 10 ppb often shields the monitoring stations from the Foehn air aloft. Trajectory calculations for the Foehn period between 19 and 24 October 1999 reveal that the Foehn air originated from below 1 to 1.5 km above the Po Basin and the Mediterranean Sea. Tethered balloon soundings in the source area south of the Alps, ozone measurements at the mountain station Jungfraujoch (3580 m a.s.l.) and airborne measurements across the Alpine crests reveal that the ozone levels found in the Foehn air correspond to the concentrations just above the mixing height in the Po Basin and are transported across the Alpine crest within the lowest flow layer.     

Species-specific responses of herbivores to within-plant and environmentally mediated between-plant variability in plant chemistry

Allocation of resources to growth and defense against herbivores crucially affects plant competitiveness and survival, resulting in a specific distribution of assimilates and defense compounds within plant individuals. Additionally, plants rarely experience stable environmental conditions, and adaptations to abiotic and biotic stresses may involve shifts in resistance to herbivores. We studied the allocation of phytochemicals in Brassica oleracea (Brussels sprouts) due to leaf age, drought stress and herbivore damage and assessed effects on two lepidopteran herbivores differing in diet breadth: the generalist Spodoptera littoralis and the specialist Pieris brassicae. Glucosinolates as secondary defense compounds and total nitrogen and carbon were quantified and linked to plant palatability, i.e., herbivore feeding preference. Herbivore responses were highly species-specific and partially related to changes in phytochemicals. Spodoptera littoralis preferred middle-aged leaves with intermediate levels of glucosinolates and nitrogen over young, glucosinolate and nitrogen rich leaves, as well as over old leaves, poor in glucosinolates and nitrogen. In contrast, P. brassicae preferred young leaves. Both species preferred severely drought-stressed plants to the well-watered control, although analyzed glucosinolate concentrations did not differ. Both S. littoralis and P. brassicae feeding induced an increase of indole glucosinolate levels, which may explain a reduced consumption of damaged plants detected for S. littoralis but not for P. brassicae. By revealing distinct, sometimes contrasting responses of two insect herbivores to within-plant and stress-mediated intraspecific variation in phytochemistry of B. oleracea, this study emphasizes the need to consider specific herbivore responses to understand and predict the interactions between herbivores and variable plants.     

The cockle <Emphasis Type="Italic">Cerastoderma edule</Emphasis> at Northeast Atlantic shores: genetic signatures of glacial refugia

The cockle Cerastoderma (Cardium) edule (L.) ranges from NW Africa to northern Scandinavia. Abundance in shallow coastal sediment is often high, and it attracts commercial harvest. In this study, a complex genetic pattern has been revealed by mitochondrial DNA in 383 individuals from 19 sampling sites. Parsimony network analysis of 79 haplotypes identified two dominant central haplotypes separated by low divergence. One is characteristic for a homogenous southwestern group of populations from Africa to the British Isles. The other is characteristic for a heterogeneous northern group with a deviant Arctic population. At the entrance of the Baltic Sea, a mixture zone of the dominant haplotypes was found. The estimated population expansion time for the northern haplotype group predates that of the southwestern one, suggesting northern glacial refugia and a subsequent southern expansion of C. edule populations.     

Nickel partitioning in formulated and natural freshwater sediments

A natural, field-collected sediment high in organic carbon (OC) and low in acid-volatile sulfide (AVS) was used to evaluate nickel (Ni) complexation to organic matter (OM) over a range of pH under anoxic conditions. It was found that OM strongly influenced Ni partitioning and that Ni complexation to OM was significantly influenced by pH, with complexation increasing with increasing pH (from pH 6 to 8). Using an equilibrium partitioning approach incorporating both [SEM(Ni)]-[AVS] and OC content, lethal and non-lethal toxicity test endpoints were calculated (predicted) and compared to observed toxicity test results using the amphipod, Hyalella azteca, exposed to four Ni-spiked natural sediments varying in OC and AVS content. Generally, lethal and non-lethal toxicity test endpoints were reasonably predictable in low AVS sediments. Due to the apparent lack of equilibrium between dissolved pore-water Ni and the pure Ni sulfide (likely the result of additional dissolved metal binding ligands), and the possible competition of liberated Fe2+ with Ni2+ for binding sites on organic matter, toxicity predictions (based on sediment OC and AVS content) overestimated the combined protective effects of AVS and OC in the sediments containing mid to high (27.87-44.05 micromol/g d.w.) AVS concentrations. Overall, it was found that equilibrium partitioning-based sediment quality guidelines can be improved through the incorporation of nickel complexation to sedimentary OM (in addition to AVS), although further research is required to fully describe nickel-OM interaction.     

Availability of radium isotopes and heavy metals from scales and tailings of Polish hard coal mining

Radium and heavy metal contaminated tailings and scales resulting from Polish hard coal mining were investigated for their mobilisation potential by using leaching methods. The main focus is set on a three-step extraction procedure proposed by BCR (Bureau Communautaire de Référence, now Standards Measurements and Testing Programme) of the European Union, which was used for investigating the availability of radium isotopes. In addition, the results of a Polish extraction procedure for the heavy metals' water solubility are presented for rough comparison. After a special treatment, the BCR-reagents were measured by gamma-spectrometry to define their radium activity concentrations; the heavy metal content in the water soluble fractions was determined by ICP-AES. The samples were collected at two different sites influenced by the discharge of pit water from hard coal mining. The tailings were taken from a former tailing pond, which now is no longer in use, but the settled material is still present. At another abandoned and meanwhile flooded tailing pond, the scales were scraped from the inside of a discharge tube. The results obtained show that there is different leaching behaviour between the radium isotopes. The tailings being characterised by surface adsorbed radium provide up to 25% of the initial (226)Ra content, (228)Ra is altogether leached up to 15%. The scales comprise stable radiobaryte (Ba[Ra]SO(4)) and can be considered as being unable to provide radium isotopes, since no trace of radium dissolution was observed. The leaching behaviour of heavy metals is similar to that of radium. Mn, Ni and Zn are dissolved by water from the tailings; the scales do not provide any.     

Overview of Traditional and Environmental Factors Related to Bone Health

Environmental Science and Pollution Research - Bone mass in adulthood depends on growth and mineralization acquired during childhood and adolescence. It is well known that these stages of life are...