Arsenic concentration and speciation in five freshwater fish species from Back Bay near Yellowknife, NT, CANADA

The concentration of total arsenic and five different arsenic species [As(III), As(V), monomethylarsonic acid (MMA), dimethylarsenic acid (DMA), and arsenobetaine (AsB)], were measured in the muscle, liver and gastrointestinal tract (GIT) of five different fish species [lake whitefish (Coregonus clupeaformis), walleye (Stizostedion vitreum), northern pike (Esox lucius), white sucker (Catostomus commersoni) and longnose sucker (Catostomus catostomus)] from Back Bay, Great Slave Lake, near the city of Yellowknife, NT, Canada. The total concentration (dry weight) of arsenic in muscle ranged from 0.57 to 1.15 mg/kg, in the liver from 0.42 to 2.52 mg/kg and in the GIT from 1.48 to 8.92 mg/kg. Among fish species, C. commersoni had significantly higher total arsenic concentrations in the GIT than S. vitreum, E. lucius and C. clupeaformis, and higher total arsenic concentrations in the liver than C. clupeaformis. The mean concentration of As(III) and As(V) in the muscle of all fish ranged from < or =0.01 to 0.05 mg/kg and < or =0.01 to 0.02 mg/kg, respectively, and together comprised < or =7.5% of the total arsenic measured in muscle. The concentrations of MMA were below detection in the muscle of all five fish species. However, AsB and DMA were measured in all fish species and nearly all fish tissues. The concentrations of AsB ranged from 0.01 to 0.13 mg/kg and the concentrations of DMA ranged from <0.02 to 0.45 mg/kg. The majority (>50%) of organic arsenic in almost all of the tissues from fish caught in Back Bay was not directly identified. Evidence from the literature suggests that most of these other organic arsenic species were likely trimethylated arsenic compounds, however, further analytical work would need to be performed to verify this hypothesis.     

Mechanisms to exclude local people from forests: Shifting power relations in forest transitions

Forest transitions may significantly contribute to climate change mitigation but also change forest use, affecting the local people benefiting from forests. We analyze forest transitions as contested processes that simplify multifunctional landscapes and alter local livelihoods. Drawing on the Theory of Access, we develop a conceptual framework to investigate practices of multifunctional forest use and the mechanisms that exclude local forest use(r)s during forest transitions in nineteenth century Austria and twenty-first century Lao PDR. Based on historical sources, interviews and secondary literature, we discuss legal, structural and social-metabolic mechanisms to exclude multifunctional forest practices, marginalizing peasants and shifting cultivators. These include, for example, the increasing enforcement of private ownership in forests or the shift from fuelwood to coal in Austria and restrictive land use planning or the expansion of private land concessions in Laos. By integrating political ecology and environmental history in forest transitions research we unravel shifting power relations connected to forest change.     

Kinetics of phenanthrene desorption from activated carbons to water

We determined the kinetics of phenanthrene desorption from three activated carbons to water using Tenax beads as an infinite sink for organic compounds in water. Desorption kinetic data very well fitted a biphasic kinetic model based on the presence of two different adsorption sites, viz. low-energy sites and high-energy sites. Rate constants for desorption to water from these two types of sites in the three activated carbons did not reveal a relation with activated carbon grain size. These rate constants were comparable to those for desorption of various organic compounds from hard carbon in various sediments.     

Environmental assessment of solid waste landfilling technologies by means of LCA-modeling

By using life cycle assessment (LCA) modeling, this paper compares the environmental performance of six landfilling technologies (open dump, conventional landfill with flares, conventional landfill with energy recovery, standard bioreactor landfill, flushing bioreactor landfill and semi-aerobic landfill) and assesses the influence of the active operations practiced on these performances. The environmental assessments have been performed by means of the LCA-based tool EASEWASTE, whereby the functional unit utilized for the LCA is "landfilling of 1ton of wet household waste in a 10m deep landfill for 100 years". The assessment criteria include standard categories (global warming, nutrient enrichment, ozone depletion, photo-chemical ozone formation and acidification), toxicity-related categories (human toxicity and ecotoxicity) and impact on spoiled groundwater resources. Results demonstrate that it is crucially important to ensure the highest collection efficiency of landfill gas and leachate since a poor capture compromises the overall environmental performance. Once gas and leachate are collected and treated, the potential impacts in the standard environmental categories and on spoiled groundwater resources significantly decrease, although at the same time specific emissions from gas treatment lead to increased impact potentials in the toxicity-related categories. Gas utilization for energy recovery leads to saved emissions and avoided impact potentials in several environmental categories. Measures should be taken to prevent leachate infiltration to groundwater and it is essential to collect and treat the generated leachate. The bioreactor technologies recirculate the collected leachate to enhance the waste degradation process. This allows the gas collection period to be reduced from 40 to 15 years, although it does not lead to noticeable environmental benefits when considering a 100 years LCA-perspective. In order to more comprehensively understand the influence of the active operations (i.e., leachate recirculation, waste flushing and air injection) on the environmental performance, the time horizon of the assessment has been split into two time periods: years 0-15 and 16-100. Results show that if these operations are combined with gas utilization and leachate treatment, they are able to shorten the time frame that emissions lead to environmental impacts of concern.     

Work–family conflict and neck and back pain in surgical nurses

Objective. Surgical nurses’ work is physically and mentally demanding, possibly leading to work–family conflict (WFC). The current study tests WFC to be a risk factor for neck and lower back pain (LBP). Job influence and social support are tested as resources that could buffer the detrimental impact of WFC. Methods. Forty-eight surgical nurses from two university hospitals in Germany and Switzerland were recruited. WFC was assessed with the Work–Family Conflict Scale. Job influence and social support were assessed with the Copenhagen Psychosocial Questionnaire, and back pain was assessed with the North American Spine Society Instrument. Results. Multiple linear regression analyses confirmed WFC as a significant predictor of cervical pain (β?=?0.45, p?β?=?0.33, p?=?0.012). Job influence and social support did not turn out to be significant predictors and were not found to buffer the impact of WFC in moderator analyses. Conclusion. WFC is likely to affect neck and back pain in surgery nurses. Work–life interventions may have the potential to reduce WFC in surgery nurses.     

Agricultural waste as household fuel: Techno-economic assessment of a new rice-husk cookstove for developing countries

In many rural contexts of the developing world, agricultural residues and the organic fraction of waste are often burned in open-air to clear the lands or just to dispose them. This is a common practice which generates uncontrolled emissions, while wasting a potential energy resource. This is the case of rice husk in the Logone Valley (Chad/Cameroon). In such a context household energy supply is a further critical issue. Modern liquid fuel use is limited and traditional solid fuels (mainly wood) are used for daily cooking in rudimentary devices like 3-stone fires, resulting in low efficiency fuel use, huge health impacts, increasing exploitation stress for the local natural resources. Rice husk may be an alternative fuel to wood for household energy supply. In order to recover such a biomass, the authors are testing a proper stove with an original design. Its lay-out (featuring a metal-net basket to contain the fuel and a chimney to force a natural air draft) allows a mix of combustion/gasification of the biomass occurring in a completely burning fire, appropriate for cooking tasks. According to results obtained with rigorous test protocols (Water Boiling Test), different lay-outs have been designed to improve the performance of the stove. Technical and economic issues have been addressed in the development of such a model; building materials have been chosen in order to guarantee a cost as low as possible, using locally available items. The feasibility of the introduction of the stove in the studied context was assessed through an economic model that keeps into account not only the technology and fuel costs, but also the energy performance. According to the model, the threshold for the trade-off of the stove is the use of rice husk to cover 10–15% of the household energy needs both with traditional fireplaces or with improved efficiency cookstoves. The use of the technology proposed in combination with improved woodstove would provide householders with an appropriate and convenient cooking technology portfolio, increasing the opportunities of choice of the preferred energy system for the user and allowing significant savings for the family budget (up to 50% of the total annual cooking energy expenditure). The proposed model may be used also as a tool for the evaluation of the affordability or for the comparison of different cooking technologies also in other similar contexts, given their specific techno-economic parameter values.     

Environmental assessment of gas management options at the Old Ämmässuo landfill (Finland) by means of LCA-modeling (EASEWASTE)

The current landfill gas (LFG) management (based on flaring and utilization for heat generation of the collected gas) and three potential future gas management options (LFG flaring, heat generation and combined heat and power generation) for the Old Ämmässuo landfill (Espoo, Finland) were evaluated by life-cycle assessment modeling. The evaluation accounts for all resource utilization and emissions to the environment related to the gas generation and management for a life-cycle time horizon of 100 yr. The assessment criteria comprise standard impact categories (global warming, photo-chemical ozone formation, stratospheric ozone depletion, acidification and nutrient enrichment) and toxicity-related impact categories (human toxicity via soil, via water and via air, eco-toxicity in soil and in water chronic).The results of the life-cycle impact assessment show that disperse emissions of LFG from the landfill surface determine the highest potential impacts in terms of global warming, stratospheric ozone depletion, and human toxicity via soil. Conversely, the impact potentials estimated for other categories are numerically-negative when the collected LFG is utilized for energy generation, demonstrating that net environmental savings can be obtained. Such savings are proportional to the amount of gas utilized for energy generation and the gas energy recovery efficiency achieved, which thus have to be regarded as key parameters. As a result, the overall best performance is found for the heat generation option – as it has the highest LFG utilization/energy recovery rates – whereas the worst performance is estimated for the LFG flaring option, as no LFG is here utilized for energy generation.Therefore, to reduce the environmental burdens caused by the current gas management strategy, more LFG should be used for energy generation. This inherently requires a superior LFG capture rate that, in addition, would reduce fugitive emissions of LFG from the landfill surface, bringing further environmental benefits.     

Seasonal decline of offspring quality in the European starling Sturnus vulgaris: an immune challenge experiment

In seasonally fluctuating environments, timing of reproduction is a crucial determinant of fitness. Studies of birds show that late breeding attempts generally result in offspring of lower reproductive value, with lower recruitment and long-term survival prospects. Several proximate mechanisms, including a seasonal decline of immune system functioning, may lead to a seasonal decline of offspring fitness. We investigated seasonal variation in offspring quality by subjecting first- and second-brood chicks of a sexually size dimorphic species, the European starling Sturnus vulgaris, to an immune challenge with a bacterial endotoxin (LPS), and evaluated their growth and physiological response in terms of total plasma antioxidant capacity (TAC), concentration of reactive oxygen metabolites and hematocrit. LPS challenge did not affect chick growth or oxidative status. However, hematocrit of second-brood chicks was higher in LPS chicks compared to controls. Body mass halfway through the rearing period (days?8–9 post-hatching), TAC and hematocrit were lower among second- vs. first-brood chicks. Interestingly, sexual dimorphism in body mass at days?8–9 post-hatching markedly differed between broods, first-brood males being 4.7% and second-brood males 22.7% heavier than their sisters, respectively. Pre-fledging mortality occurred among second-brood chicks only and was strongly female-biased. Our findings suggest that starling chicks, even if in poor conditions, are little affected by a bacterial challenge, at least in the short-term. Moreover, our study indicates that sex differences in body size, possibly mediated by sex-specific maternal investment in egg size, may heavily impact on pre-fledging survival in a different way in the course of the breeding season, resulting in sex-specific seasonal decline of offspring fitness. Finally, we suggest that levels of circulating antioxidants should be regarded among the proximate causes of the association between timing of fledging and long-term survival in avian species.