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.     

Longitudinal and vertical trends in stable isotope signatures (δ13C and δ15N) of omnivorous and carnivorous copepods across the South Atlantic Ocean

Stable isotope (SI) ratios of carbon (δ¹³C) and nitrogen (δ¹⁵N) were measured in omnivorous and carnivorous deep-sea copepods of the families Euchaetidae and Aetideidae across the Atlantic sector of the Southern Ocean to establish their trophic positions. Due to high and variable C/N ratios related to differences in lipid content, δ¹³C was corrected using a lipid-normalisation model. δ¹⁵N signals ranged from 3.0–6.9‰ in mesopelagic species to 7.0–9.5‰ in bathypelagic congeners. Among the carnivorous Paraeuchaeta species, the epi- to mesopelagic species Paraeuchaeta antarctica had lower δ¹⁵N values than the mesopelagic P. rasa and bathypelagic P. barbata. The same trend was observed among omnivorous Aetideidae, but was not significant. In the most abundant species P. antarctica, individuals from the western Atlantic had higher δ¹³C and δ¹⁵N values than specimens at the eastern stations. These longitudinal changes in δ¹³C and δ¹⁵N values were attributed to regional differences in hydrography and sea surface temperature (SST), in particular related to a northward extension of the Antarctic Polar Front (APF) at the easternmost stations. The results indicate that even in a mesopelagic carnivorous species, the changes in surface stable isotope signatures are pronounced.     

Trace element concentration in wheat grain: results from the Swedish long-term soil fertility experiments and national monitoring program

Concentrations of trace elements in wheat grain sampled between 1967 and 2003 from the Swedish long-term soil fertility experiments were analyzed using ICP-MS. The long-term effect of inorganic and organic fertilization on trace metal concentrations was investigated including the impact of atmospheric deposition and myccorhiza, whereas other factors such as soil conditions, crop cultivar, etc. are not discussed in this paper. Mean values derived from 10 experimental sites were reported. Significantly declining Pb and Cd concentrations in wheat grain could be explained by lower atmospheric deposition. Mean Se contents in all samples were 0.031 mg kg⁻¹ grain dry weight. No samples had sufficiently high Se concentrations for human (0.05 mg Se kg⁻¹) or animal demand (0.1 mg Se kg⁻¹). Concentrations of Co in wheat grain were extremely low, 0.002–0.005 mg Co kg⁻¹ grain dry weight, and far below the minimum levels required by animals, which applied to all fertilizer treatments. A doubling of Mo concentrations in grain since 1975 resulted in Cu/Mo ratios often below one, which may cause molybdenosis in ruminants. The increase in Mo concentrations in crops correlated with the decline in sulfur deposition. Concentrations of Cu and Fe declined in NPK-fertilized wheat as compared to unfertilized or manure-treated wheat. Very low concentrations of Se and Co and low concentrations of Fe and Cu require attention to counteract risks for deficiencies. The main characteristic of the study is that there are few significant changes over time between different fertilizer treatments, but throughout there are low concentrations of most trace elements in all treatments. In general, good agreement between concentrations in wheat from the long-term fertility experiments and the national monitoring program indicate that values are representative.     

Migration of aluminum from food contact materials to food—a health risk for consumers? Part II of III: migration of aluminum from drinking bottles and moka pots made of aluminum to beverages

Background

Drinking bottles and stove-top moka pots made of aluminum have become very popular. Storing drinks in bottles and preparing coffee in a moka pot may result in the migration of aluminum to the beverage.

Results/Conclusions

In a systematic study of aluminum drinking bottles, it has been shown that drinking a mixture of apple juice and mineral water in an aluminum bottle may reach 86.6% of the total weekly intake (TWI) for adults, and drinking tea from an aluminum bottle may exceed the TWI (145%) for a child weighing 15 kg. In contrast, preparing coffee in an aluminum moka pot results in a maximum of 4% to TWI, if an average of 3.17 L coffee is consumed per week, even if the pots are washed in the dishwasher, against the explicit instructions of the manufacturer.

     

Migration of aluminum from food contact materials to food—a health risk for consumers? Part I of III: exposure to aluminum,release of aluminum,tolerable weekly intake (TWI), toxicological effects of aluminum,study design,and methods

Background

In spite of the prevalence of aluminum in nature, no organism has been found to date which requires this element for its biological functions. The possible health risks to human beings resulting from uptake of aluminum include detrimental effects to the hemopoietic system, the nervous system and bones. Aluminum is used in many fields and occurs in numerous foodstuffs. Food contact materials containing aluminum represent an anthropogenic source of dietary aluminum.

Results

As a result of their frequent use in private households a study was undertaken to detect migration of this metal to foodstuffs from drink containers, coffee pots, grill pans, and camping cookware made of aluminum.

Conclusions

An estimate of the health risk to consumers is calculated, based on the tolerable weekly intake (TWI) specified by the European Food Safety Authority of 1 mg/kg body weight for all groups of people. In some instances the TWI is significantly exceeded, dependent upon the food contact material and the food itself.

     

Brood defense and age of young: a test of the vulnerability hypothesis

Summary In many altricial species including the great tit (Parus major) the intensity of brood defense against predators has been shown to increase with the age of the offspring. This effect has been ascribed amongst others to the young becoming more vulnerable as they age (vulnerability hypothesis). In a great tit population suffering heavy losses from brood depredation by the great spotted woodpecker (Dendrocopus major), we rendered first and second broods more vulnerable by artificially enlarging the entrance of the nest hole. Contrary to the vulnerability hypothesis, 16 experimental pairs defended their brood against a dummy great spotted woodpecker less vigorously than did 16 control pairs. Nest concealment behavior potentially compromising active defense was minimized by simultaneous playback of nestling distress calls, thus simulating the act of nest predation. This leaves the brood value hypothesis as an alternative functional explanation of the defense level — age effect. It predicts that parents should defend their brood in proportion to the reproductive value (or some more suitable cohortal equivalent measure) of their offspring. At present, this explanation pertains to one predator species. In first broods, but not in second broods, males defended them more vigorously than did their females. While this parallels previous experiments on brood defense against predators posing a much greater risk to the parents, two functional explanations previously put forward can hardly apply.     

Removal of hexafluoroarsenate from waters

Arsenic predominantly occurs in natural ground and surface waters as arsenate and arsenite. Other arsenic species can also be present in anthropogenically influenced waters. By means of a newly-developed speciation technique an arsenic compound was identified as hexafluoroarsenate at high concentration (about 0.8mgl(-1) as As) in a lake polluted by waste water from a former crystal glass factory. This compound shows a completely different behavior than common arsenite and arsenate in waters. However, respective literature data were little found regarding its environmental behavior as well as the applicable remediation technologies. Conventional arsenic treatment mechanisms, such as the well-known sorption to iron hydroxides, can not be used to remediate water with this compound. Hence, an effective method to remove hexafluoroarsenate from water was developed using its strong affinity to anion exchangers (strong basic exchangers with quaternary ammonium groups). The sorption can be described by a Langmuir isotherm and first-order kinetics with a half-life of about 10min. Interferences by sulphate and fluoride, present at much higher concentrations in the polluted lake water, might be expected due to the anion exchange mechanism, but were shown to be of minor importance.     

Environmental risks of farmed and barren alkaline coal ash landfills in Tuzla, Bosnia and Herzegovina

The disposal of coal combustion residues (CCR) has led to a significant consumption of land in the West Balkan region. In Tuzla (Bosnia and Herzegovina) we studied previously soil-covered (farmed) and barren CCR landfills including management practises, field ageing of CCR and the transfer of trace elements into crops, wild plants and wastewaters. Soil tillage resulted in mixing of cover soil with CCR. Medicago sativa showed very low Cu:Mo ratios (1.25) which may cause hypocuprosis in ruminants. Total loads of inorganic pollutants in the CCR transport water, but not pH ( approximately 12), were below regulatory limits of most EU countries. Arsenic concentrations in CCR transport water were <2microgl(-1) whereas reductive conditions in an abandoned landfill significantly enhanced concentrations in leachates (44microgl(-1)). The opposite pattern was found for Cr likely due to large initial leaching of CrVI. Public use of landfills, including farming, should be based on a prior risk assessment due to the heterogeneity of CCR.     

Investigation on the chemical structure of nonextractable residues of the fungicide cyprodinil in spring wheat using 13C-C1-phenyl-cyprodinil on 13C-depleted plants-an alternative approach to investigate nonextractable residues

13C-labelled cyprodinil was applied on 13C-depleted wheat plants with 27-fold field application rate. A control experiment applying same amounts of 14C-cyprodinil showed that main portions of the residues were detected in the cellulose (15% NER), hemicellulose (28.3% NER), and lignin fraction (23.3% NER). 16.7% were detected in water soluble polymers, 6% in both, pectin and protein fraction, and 4% in the starch containing fraction. Free cyprodinil was detectable by TLC in all fractions except lignin. A direct characterization of the residues in vivo by CP-MAS was not successful. Cell wall fractions were further analysed by liquid state NMR to determine the structure of the mobilized highly polymer/polar residues: Within lignin, where most of the residues were located at field application rate, neither intact cyprodinil nor its metabolites could not be detected. The 13C-label introduced was probably incorporated in the polymer as natural lignin monomers and thus are not considered as bound residues according to IUPAC definition.