Sample damage during X-ray fluorescence analysis--case study on ammonium salts in atmospheric aerosols

Atmospheric aerosols can consist of, amongst others, compounds like NH(4)NO(3) or (NH(4))(2)SO(4). Such components can suffer radiation damage and/or evaporate during EDXRF measurements, providing errors on successively applied analysis. The aim of this work is to investigate the influence of measurements using conventional EDXRF on the volatile compounds and to compare it with the influence of polarized beam EDXRF using secondary targets (and hence indirect irradiation). The effect of different parameters (acquisition time, accelerating voltage, current and medium) on the concentration loss was studied. The measurements performed in vacuum during a long period lead to the highest losses of volatile compounds. The influence of direct irradiation was proved to be larger than the indirect variant.     

A Native Species with Invasive Behaviour in Coastal Dunes: Evidence for Progressing Decay and Homogenization of Habitat Types

A new species has recently invaded coastal dune ecosystems in North West Europe. The native and expansive inland grass, Deschampsia flexuosa, progressively dominating inland heaths, has recently invaded coastal dunes in Denmark, occasionally even as a dominant species. A total of 222 coastal locations with 5,000 random sample plots have been investigated. These findings are in contrast to historical records, and D. flexuosa has never been considered belonging to coastal dune ecosystems. The occurrence of the typical inland grass in the coastal dunes is a strong indication of increase in nutrient level and that human influences may cause a native species to be invasive in new ecosystems. This could be a radical example of change in species composition due to a long lasting exceedance of critical load of nitrogen. The investigation also showed a general increase in cover of the most dominant species.     

Rheological Studies of Microfibrillar Cellulose Water Dispersions

The rheological behaviour of microfibrillar cellulose (MFC) water dispersions has been investigated. For the first time a detailed study of shear dependent viscosity at low and high shear rate is presented. A peculiar time dependent behaviour measured in the area between 0 and 1000 s⁻¹ was identified. The study shows a hysteresis loop in the shear rate–viscosity relationship at low shear rate. Additional time dependent shear rate measurements were performed, and a hypothesis for a mechanism of interaction and formation of a fibrils network was suggested. Higher temperature caused lower viscosity values, and this difference was increased at higher shear rate values. Oscillatory measurements showed how the closeness of the fibrils helps network creations. Data obtained from high shear measurements showed that 1% MFC water dispersions had a dilatant behaviour at ultra high shear rates with values increasing from 120 to 300 Pa s in the area between 180,000 and 330,000 s⁻¹ .     

Science and Society in Dialogue About Marker Assisted Selection

Analysis of a European Union funded biotechnology project on plant genomics and marker assisted selection in Solanaceous crops shows that the organization of a dialogue between science and society to accompany technological innovations in plant breeding faces practical challenges. Semi-structured interviews with project participants and a survey among representatives of consumer and other non-governmental organizations show that the professed commitment to dialogue on science and biotechnology is rather shallow and has had limited application for all involved. Ultimately, other priorities tend to prevail because of high workload. The paper recommends including results from previous debates and input from societal groups in the research design phase (prior to communication), to use appropriate media to disseminate information and to make explicit how societal feedback is used in research, in order to facilitate true dialogue between science and society on biotechnology.     

Can a key boreal Calanus copepod species now complete its life-cycle in the Arctic? Evidence and implications for Arctic food-webs

The changing Arctic environment is affecting zooplankton that support its abundant wildlife. We examined how these changes are influencing a key zooplankton species, Calanus finmarchicus, principally found in the North Atlantic but expatriated to the Arctic. Close to the ice-edge in the Fram Strait, we identified areas that, since the 1980s, are increasingly favourable to C. finmarchicus. Field-sampling revealed part of the population there to be capable of amassing enough reserves to overwinter. Early developmental stages were also present in early summer, suggesting successful local recruitment. This extension to suitable C. finmarchicus habitat is most likely facilitated by the long-term retreat of the ice-edge, allowing phytoplankton to bloom earlier and for longer and through higher temperatures increasing copepod developmental rates. The increased capacity for this species to complete its life-cycle and prosper in the Fram Strait can change community structure, with large consequences to regional food-webs.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01667-y.     

Risk assessment of dioxins and dioxin-like PCBs in food--comments by the German Federal Environmental Agency

Human health risk assessments for dioxins and dioxin-like PCBs (with the exception of the one by US-EPA) recommend health based exposure limits within the range of 1-4 pg WHO-TEQ/kg bw per day. As all humans are exposed to measurable levels of dioxins and related substances, the determination of the tolerated daily intake is a very significant decision and may influence limit values guiding risk reduction measures and target levels. The proposed TDI has to protect all human subpopulations. In the case of dioxin this is particularly important as the exposure of infants through breast-feeding may exceed the exposure of adults by one or two orders of magnitude. An overview of recently recommended limit values (WHO, SCF, JECFA) for PCDDs, PCDFs and dioxin-like PCBs using WHO-TEFs shows the common feature that the values were derived only from non carcinogenic endpoints. In November 2000 the Scientific Committee on Food of the European Commission published an 'Opinion of the SCF on the Risk Assessment of Dioxins and Dioxin-like PCBs in Food' [SCF, Scientific Committee on Food 2000. Opinion of the SCF on the risk assessment of dioxins and dioxin-like PCBs in food. European Commission, Brussels, Adopted on November 2000 http://europa.eu.int/comm/food/fs/sc/scf/out78_en.pdf]. On the basis of this extensive review of data and experimental results the Committee recommended a temporary tolerable weekly intake (t-TWI) of 7 pg WHO-TEQ/kg bw. Only six months later the SCF carried out a re-evaluation of its t-TWI from November 2000. The reconsideration of 'pivotal studies' led to the situation that the re-assessment is now based only on rat studies which investigated only reproductive effects only on male offspring and, in addition, three of these studies are single dose studies at gestational day 15. Applying an overall uncertainty factor of 10 to the LOAEL derived estimated human daily intakes (EHDI) the SCF concluded that 14 pg/kg bw per week should be considered as a tolerable intake for 2,3,7,8-TCDD. The SCF stated that on a body weight basis, the dioxin intake of breast-fed infants has been estimated to be one to two orders of magnitude higher than the average adult intake. Recent German data suggest that the body burden of formerly breast-fed children aged 9-11 is still about 30% higher than those of their formula-fed age-mates. As breast-feeding has measurable benefits for neurological and immunological development, formula feeding cannot be recommended as an alternative to lower dioxin intake. So the only remaining way to lower the dioxin uptake is to drastically reduce the background exposure of the general population. It is acknowledged that any recommendation of a precise number for a TDI is flawed by uncertainties and the possibility of different weight being given to the studies of relevance. The determination of the TDI has influence on all regulatory limit values that are based on the TDI value. A higher TDI lowers the level of protection for humans. It is proposed by the German Federal Environmental Agency that the TDI should be reassessed in a process transparent to the public and on the basis of all relevant endpoints from animal experiments and human epidemiology, including the assessment of cancer risks.     

Heavy metal toxicity to Lemna minor: studies on the time dependence of growth inhibition and the recovery after exposure

Environmental concentrations of toxic substances are not necessarily constant but fluctuate over time. Periods of intense exposure might be followed by episodes with a relatively low or no exposure, in principle allowing exposed organisms to recover from toxic injury. The growth reproduction assay with the limnic vascular plant Lemna minor allows for convenient studies on the time dependence of the aquatic toxicity of chemicals. Here we report on a study with four priority metals (Zn, Cu, Ni, Cd). Aims of the study were to determine the impact of the exposure duration on the observed toxicities and to determine the potential for recovery. The bioconcentrations of the test metals were recorded during the exposure in order to analyse, whether changes in the internal concentrations are a governing factor for the dynamics of toxicity. After an exposure of 7 days, Cd and Cu showed the highest toxicity to Lemna (EC50's of 1.9 and 9.7 microM respectively), while Ni and Zn had a slightly lower toxicity (EC50's of 56.3 and 46.1 microM respectively). Additionally, Zn showed a severely delayed toxicity and the exposed plants did not recover even 7 days after the exposure had ended. This is in sharp contrast to the other test metals, for which a considerable recovery was observed. These results indicate the necessity to more thoroughly consider the dynamics of toxicity, instead of recording toxic effects only after a constant exposure over a fixed time.     

Adaptive Capacity in Community Forest Management: A Systematic Review of Studies in East Asia

Environmental Management - This study investigated the indicators of adaptive capacity along with disturbances in community forest management systems in the East Asian countries, China, Japan and...     

The “social-physiology” of safety. An integrative approach to understanding organisational psychological mechanisms behind safety performance

This paper aims at contributing to a comprehensive perspective on occupational safety by integrating research on different specific organisational psychological concepts found to contribute to different types of organisational performance, and apply these to an occupational safety context. A second aim was to present perspectives on how occupational safety may be promoted within an organization. The following mechanisms are suggested. A leadership style promoting co-operation, inspiring, fostering group goals, as well as providing individualized support and empowering workers may intrinsically be expected to comprise rich and open communication and thus support the development of high-quality interactions between managers and employees. Such interaction and communication may promote the development of mutual trust, and the development of a good workgroup climate. Trust, in turn, may further promote communication and interaction. Mutual trust, high-quality relations, and a strong group climate may promote workers’ motivation and intentions to contribute to the organisational goals. Managers successful in demonstrating true and consistent priority of workers’ safety may promote the development of workers’ trust but also convince that safety is a prime organisational goal. This may promote workers’ motivation to behave safely. Trustful relations characterized by empowerment and participation are then likely also to support the realization of safety intentions into safe behavior.