Growth and reproduction of Pycnogonum litorale (Pycnogonida) under laboratory conditions

The complete life cycle of Pycnogonum litorale Ström was observed under laboratory conditions. At 15?°C and a 16?h light:8?h dark photocycle, the duration of embryonic development from oviposition to egg-hatching varied from 32 to 111?d. The onset of egg hatching ranged from 32 to 81?d after oviposition in different egg batches, and the period between the first and the last hatch within a single egg batch varied between 16 and 57?d. The larval period, consisting of five larval instars, lasted between 66 and 113?d. Juvenile development required seven (exceptionally 8 or 9) moults and lasted between 263 and 400?d. The average interval between successive moults in juveniles increased with increasing size from 24 to 82?d. Though females did not moult more often than their male conspecifics, they reached a size from 8.5 to 11.0?mm (average 10.1?mm) while adult males measured only 7.0 to 8.5?mm (average 7.7?mm). At low temperatures (2?°C) moulting was almost completely inhibited. After raising the temperature to 6?°C, the moulting frequency increased to a rate almost as high as at a constant temperature of 15?°C. Moulting was also retarded by starvation and accelerated by subsequent feeding. Adults lived for up to 9?years without further moults, with several periods of mating and oviposition at irregular intervals. In combination with previous long-term field observations, the present results provide a more complete picture of the life cycle of P. litorale in a natural habitat. The great variation in the duration of the different developmental stages, the ability to survive periods of cold and starvation, and the longevity of the adults are important for the survival of pycnogonid populations under changing environmental conditions.     

Ultrafine particles at workplaces of a primary aluminium smelter

The number concentration and size distribution of ultrafine particles in a S?derberg and a prebake potroom of an aluminium primary smelter have been measured using a scanning mobility particle spectrometer. The particle morphology was studied by transmission electron microscopy (TEM). The study shows the existence of elevated number concentrations of ultrafine particles in both potrooms. The main source of these particles is likely to be the process of anode changing. The ultrafine particles were measured directly at the source but could also be identified as episodes of high number concentrations in the general background air. Unlike the larger particles belonging to the 50-100 nm mode, the nanoparticle mode could not be detected in the TEM indicating that they may not be stable under the applied sampling conditions and/or the high vacuum in the instrument.     

Assessment of dietary exposure to PCDD/F and dioxin-like PCB in infant formulae available on the EU market

In infant period, human milk and infant formulae are the major sources of exposure to dioxins (polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (PCB). Since in many parts of Europe the mothers are increasingly reluctant to breastfeed their babies, the main objective of the present study is to assess the level of exposure of non-breast-fed infants during their early development. Consequently, the concentration levels of PCDD/F and dioxin-like PCB were determined in industrial infant formulae including "starting" (aged 0-4months) and "follow-on" (after 4months) products of milk formula, soy formula and hypoallergenic infant formula, available on the EU market. Furthermore, dietary exposure to dioxin of exclusively formula-fed infants was assessed at each month from 0 to 9months. The results suggest that dietary exposure to dioxins via formulae is higher when consuming "starting" than "follow-on" infant formulae on a body-weight basis. Estimated dietary exposure after 4months of age was always below the lowest range of the Tolerable Daily Intake (TDI) of 1pg WHO-TEQkg(-1)bwd(-1) and Provisional Tolerable Monthly Intake (PTMI) of 70pg WHO-TEQkg(-1)bwmonth(-1). The highest estimated cumulative dietary exposure to PCDD/F and dioxin-like PCB was obtained considering infants of 0-1months fed with the "starting" hypoallergenic infant formula (2.8pg WHO-TEQkg(-1)bwd(-1) and 84pg WHO-TQkg(-1)bwmonth(-1)). However, these elevated levels are much lower than those observed in some studies in breast-fed infants. The study can be used for further risk assessments in regard to infant exposure.     

Effects of 17alpha-ethinylestradiol on the reproduction of the cladoceran species Ceriodaphnia reticulata and Sida crystallina

Single-species tests allow the assessment of chronical effects of endocrine disruptors on organisms under laboratory conditions. In the current study, three-generation tests with Ceriodaphnia reticulata and Sida crystallina were carried out to examine the influence of the synthetic hormone 17alpha-ethinylestradiol (EE) on the reproduction of these cladoceran species. For each species, six different concentrations (10-500 microg/l EE) and two controls were tested with eight replicates for a duration of 4 weeks. The test was initiated by transferring one neonate individual into a test vessel which was incubated under standardized conditions. Every 2 days, the medium was renewed and life history parameters such as survivorship of the adults and juveniles, clutch size, first appearance and number of produced offspring were investigated. Acute toxicity tests showed that C. reticulata (EC50 (24 h) 1814 microg/l) was more sensitive towards the substance compared to S. crystallina (EC50 (24 h) >4100 microg/l). The juvenile phase of S. crystallina was significantly shorter at concentrations above 100 microg/l EE. For C. reticulata, 17alpha-ethinylestradiol caused a higher mortality of the newly hatched juveniles at EE concentrations above 200 microg/l. No effects were found for mortality of adult animals, birth rate, number of juveniles per female and net reproduction rate of S. crystallina and C. reticulata. Thus, sublethal effects on parental generation exposed to EE lead to disturbances in reproduction and to affection of their offspring. Negative consequences for the population dynamic cannot be excluded, e.g. the decrease of a population.     

MESIP∗: Modelling environmental scenarios in ponds

MESIP is a fugacity model which can predict the fate of organic hydrophobic chemicals in aquatic ecosystems. In this paper a short introduction to the mathematical model is presented together with a more detailed listing of the required input data. Comparison of the calculated and measured fate of a fluorescent whitening compound in an artificial outdoor pond is shown     

High-Velocity Stretching of Renewable Polymer Blends

Journal of Polymers and the Environment - We evaluated the influence of blending various renewable polymer grades and amounts to allow for high stretchability during stretching at 800 mm/s...     

Comparison of dioxin-like-response in vitro and chemical analysis of emissions and materials

Samples from industrial and domestic emissions and materials were investigated by using in vitro assays for dioxin-like-response (DLR) and chemical analysis. The results show a small part of persistent bioaccumulative toxicants (PBT) to be responsive in vitro. Clean-up procedures directed to persistence decrease the amount of inducing toxicants substantially. The comparison of biological in vitro (B) and chemical (A) analysis show ratios between B and A below 10 for DLR of persistent inductors. The consideration of PAH improved the knowledge about unknown less persistent agonists.     

Humanpharmakawirkstoffe in der Umwelt: Einträge, Vorkommen und der Versuch einer Bestandsaufnahme

Background

The presence of a large spectrum of pharmaceutical agents has been reported for aquatic environments (surface—and groundwater) and other aquatic media (influents and effluents of sewage treatment plants) in Germany and beyond, including their occurrence in drinking water. Considering the large number of pharmaceuticals produced for human use and released into the environment, various authors (Sattelberger 1999, Hanisch et al. 2004, Castiglioni et al. 2006, IWW 2006, Stockholm County Council 2006) tried to compile ‘priority lists’ focusing on those substances with environmental relevance. The following agents are included in all lists: ciprofloxacine, clarythromycine (antibiotics), carbamazepine (anti-epileptic agent), bezafibrate (lipid reducer), clofibric acid (lipid reducer metabolite), ethinylestradiol (sex hormone) and cylophosfamide (cytostatic agent). The agents erythromycine and sulfamethoxazole (antibiotics), ibuprofen, indometacine, propyphenazone (analgesics), atenolol (beta-blocker) and ifosfamide (cytostatic agent) can be found in three of four priority lists.

Results

Pharmaceuticals mainly enter the aquatic environment via effluent water, coming from wastewater treatment plants (including hospital and household sewerage), untreated discharges (e.g, secondary transfer of active agents into ground- and surface waters via sewage sludge application in agriculture and via landfill leachate) and leakages in the municipal sewer network.

Discussion

Potential activities towards a reduced release of pharmaceuticals into the environment should consider primarily the origin of the exposure to allow a separation of drug containing flows already at the source. Following the latter it would be possible to minimize the contamination of spring-, ground- and surface waters which serve as raw water resources for drinking water supply. However, considering the actual water pollution with pharmaceuticals and other substances, ‘end-of pipe’ techniques in the sewage and drinking water treatment are absolutely essential.

Conclusions

Sustainability criteria (e.g. protection of drinking water resources, habitats and biocoenoses, recycling and economizing use of resources) and economic aspects of modern sewage disposal concepts require a useful choice and combination of technical measures as components of centralized and decentralized sewage and drinking water treatment methods. It is though not realistic to cover and eliminate all pharmaceutical agents of environmental relevance equally effective even if a catalogue of potential technical treatment methods is elaborated thoroughly. Therefore, a concentration of efforts on selected drug agents, at least following initially some of the priority lists, is recommended.

Recommendations and Perspectives

The contamination of the water cycle with pharmaceuticals is nevertheless not exclusively to be solved via the application of technical methods. The BMBF (Federal Ministry for Education and Research) funded project start (Management Strategies for Pharmaceuticals in Drinking Water, www.start-project.de) therefore tries by implementation of a transdisciplinary approach to integrate technical-, behavioral-, and agent-orientated management strategies towards a more comprehensive and sustainable problem solution.     

Schadstoffbelastung durch Persorption von Bodenpartikeln

The term persorption describes the paracellular uptake of particles from the digestive tract. It has been shown that solid, hard microparticles such as starch granules, cellulose particles, fibres and crystals are incorporated from the digestive tract. It is likely that an uptake of soil contaminants may also occur via this mechanism, thereby increasing the health risks of children through soil ingestion. The aim of this study was to evaluate the significance of such soil contaminant absorption via this mechanism using data from the literature. Since no information was available on the persorption of soil particles, studies using other models had to be evaluated. The results of these studies show that a persorption of soil particles must be expected. The maximum persorption rate occurs for diameters of <35 μm which is in the range of diameters of street dust, clay and coarse clay. The persorption of these particles is therefore of significance. Data from the literature, however, does not allow an estimation of the magnitude of persorption of such soil particles. Basically, it is conceivable that a relevant ingestion of less mobile pollutants is possible through their persorption in the gastrointestinal tract. Aside from an increased internal exposure via the persorption of soil particles carrying contaminants, additional health risks may occur through the long-term deposit of such particles, the presence of potential allergens as well as through the embolisation of small vessels.