Emissions from baled municipal solid waste: I. Methodological approach for investigation of gaseous emissions.

This paper presents a methodological approach for the study of volatile organic compounds (VOCs) in air, emitted during storage of municipal solid waste in bales. Determination of VOCs was based on sampling with adsorbent tubes followed by automated analysis using on-line work-up with a thermal desorption unit directly connected to a gas chromatograph-mass spectrometer. Using calculation algorithms and multidimensional statistical analysis of large amounts of data collected, the information was compressed and visualized. The approach was applied to initial measurements of emissions of VOCs from 24 bales composed of municipal solid waste, each bale stored in a wooden box. These bales were produced using the two types of baling equipment available, resulting in cylindrical or rectangular bales, with different densities. Hundreds of different VOCs emitted from these bales sorted out into groups with different chemical structure. Differences in VOC concentrations in air were found between wastes stored in cylindrical or rectangular bales. For instance, it was found that the concentration of VOCs (relative to the concentration of toluene), in the first experiment after storing, for cylindrical bales with six layers of LDPE was 115 +/- 10 microg m(-3), while for rectangular bales it was only 64 +/- 8 microg m(-3). The procedure used for data interpretation suggested different degradation mechanisms in different types of bales. The use of multiple data interfaces, multidimensional statistics and automated chemical analysis methods are likely to be more and more common for waste companies and waste research in the near future. This is due to the interdisciplinary nature of the subject that relies heavily on various areas of science and information technology.     

Emissions from baled municipal solid waste: II. Effects of different treatments and baling techniques on the emission of volatile organic compounds.

This paper focuses on the volatile organic compound emissions from baled municipal solid waste (MSW). The analytical methodology was based on sampling with adsorbent tubes once a month during seven occasions within a time period of 1 year. Automated analyses were carried out on-line work-up with thermal desorption directly connected to a gas chromatograph-mass spectrometer. The effect of different baling techniques, cylindrical and rectangular baling was compared. It was found that cylindrically baled MSW emitted larger concentration of esters than their rectangular counter parts. Conversely, aromatic compounds emissions dominated in rectangularly baled MSW. This indicates that different degradation mechanisms operate in the waste bales. Cylindrical and rectangular bales are generally wrapped with six layers of 250 microm thick low density polyethylene (LDPE). It was observed that by wrapping an extra six layers of LDPE film onto the bales, the emissions from cylindrical bales increased while emissions from the rectangular counterpart decreased. Over time, the volatile organic compound emissions from cylindrical bales decreased two orders of magnitudes from 96.2 +/- 20.8 microg m(-3) in September 2003 to 0.80 +/- 0.07 microg m(-3) in July 2004. The rectangular bales exhibited an almost identical relative emission reduction from 54.4 +/- 4.3 microg m(-3) in September 2003 to 0.46 +/- 0.02 microg m(-3) in July 2004. Future work will concentrate on full-scale storages, taking into account waste type, storage size, temperature development and the different baling techniques among other variables.     

Pooled analysis of two Swedish case-control studies on the use of mobile and cordless telephones and the risk of brain tumours diagnosed during 1997-2003.

Here we present the pooled analysis of 2 case-control studies on the association of brain tumours with mobile phone use. Use of analogue cellular phones increased the risk for acoustic neuroma by 5%, 95% confidence interval (CI) = 2-9% per 100 hrs of use. The risk increased for astrocytoma grade III-IV with latency period with highest estimates using >10-year time period from first use of these phone types. The risk increased per one year of use of analogue phones by 10%, 95% CI = 6-14%, digital phones by 11%, 95% CI = 6-16%, and cordless phones by 8%, 95% CI = 5-12%. For all studied phone types OR for brain tumours, mainly acoustic neuroma and malignant brain tumours, increased with latency period, especially for astrocytoma grade III-IV.     

An approach for particle sinking velocity measurements in the 3–400?μm size range and considerations on the effect of temperature on sinking rates

The flux of organic particles below the mixed layer is one major pathway of carbon from the surface into the deep ocean. The magnitude of this export flux depends on two major processes—remineralization rates and sinking velocities. Here, we present an efficient method to measure sinking velocities of particles in the size range from approximately 3–400?μm by means of video microscopy (FlowCAM^?). The method allows rapid measurement and automated analysis of mixed samples and was tested with polystyrene beads, different phytoplankton species, and sediment trap material. Sinking velocities of polystyrene beads were close to theoretical values calculated from Stokes’ Law. Sinking velocities of the investigated phytoplankton species were in reasonable agreement with published literature values and sinking velocities of material collected in sediment trap increased with particle size. Temperature had a strong effect on sinking velocities due to its influence on seawater viscosity and density. An increase in 9?°C led to a measured increase in sinking velocities of ~40?%. According to this temperature effect, an average temperature increase in 2?°C as projected for the sea surface by the end of this century could increase sinking velocities by about 6?% which might have feedbacks on carbon export into the deep ocean.     

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.     

Games Real Farmers Play: Knowledge,memory and the fate of collective action to prevent eutrophication of water catchments

This paper analyses the outcome of an actor game aimed at finding ways to institutionalise farmer co-operation in a water catchment threatened by eutrophication from heavy use of fertilisers. Although offered several advantageous options for collective action, acting farmers stuck to their preference for individual management in spite of very draconian measures from central authorities. Theories on collective action developed by Mancur Olson and Elinor Ostrom cover some ground in explaining this puzzling outcome, as do Fritz Scharpf's models of games played out under the 'shadow of hierarchy'. However, the most decisive factor for the farmers' choice of strategy seems to stand Mancur Olson's theory on its head, and adds to the importance of trust and reciprocity emphasised by Elinor Ostrom. Because the farmers knew each other well, and because of the transparency of farmers' action in the geographically limited catchment, they turned down options of co-operation; too few farmers were considered trustworthy enough to make it worthwhile to engage in collective action. Theories of 'collective memories of the history of play' in an area or on an issue should thus be given more concern in future efforts to bring about collective action towards common pool resources. Este documento analiza el resultado de juego de actor dirigido a encontrar formas de institucionalizar la cooperación entre agricultores en la captación de agua amenazada por eutroficación de fuerte uso de fertilizantes. Aunque ofrecieron varias opciones ventajosas para la acción colectiva, los agricultores participantes se quedan apegados a sus preferencias de manejo individual a pesar de las medidas bastante draconianas de las autoridades centrales. Las teorias de acción colectiva desarrolladas por Mancur Olson y Elinor Ostrom cubren algún terreno en explicar este curioso resultado, al igual que los modelos de juego de Fritz Scharpf jugados bajo la "sombra de jerarquia". Sin embargo, el factor mas decisivo para la estrategia de decisión de los agricultores parece poner la teoria de Mancur Olson de revéz y se suma a la importancia de la confianza y reciprocidad enfatizada por Elinor Ostrom. Debido a que los agricultores se conocian bien y a la transparencia de la accion de agricultores en la captacion limitada geograficamente, ellos rechazaron opciones de cooperación; muy pocos agricultores fueron considerados de suficiente confianza para que merecieran participar en acción colectiva. Las teorias de "memorias colectivas de la historia del juego" en una área o sobre un asunto deben de esta manera estar mostrando mayor interes en esfuerzos futuros para atraer la acción colectiva hacia recursos de fondo común.