Particulate matter speciation profiles for light-duty gasoline vehicles in the United States

Representative profiles for particulate matter particles less than or equal to 2.5 µm (PM_2.5) are developed from the Kansas City Light-Duty Vehicle Emissions Study for use in the U.S. Environmental Protection Agency (EPA) vehicle emission model, the Motor Vehicle Emission Simulator (MOVES), and for inclusion in the EPA SPECIATE database for speciation profiles. The profiles are compatible with the inputs of current photochemical air quality models, including the Community Multiscale Air Quality Aerosol Module Version 6 (AE6). The composition of light-duty gasoline PM_2.5 emissions differs significantly between cold start and hot stabilized running emissions, and between older and newer vehicles, reflecting both impacts of aging/deterioration and changes in vehicle technology. Fleet-average PM_2.5 profiles are estimated for cold start and hot stabilized running emission processes. Fleet-average profiles are calculated to include emissions from deteriorated high-emitting vehicles that are expected to continue to contribute disproportionately to the fleet-wide PM_2.5 emissions into the future. The profiles are calculated using a weighted average of the PM_2.5 composition according to the contribution of PM_2.5 emissions from each class of vehicles in the on-road gasoline fleet in the Kansas City Metropolitan Statistical Area. The paper introduces methods to exclude insignificant measurements, correct for organic carbon positive artifact, and control for contamination from the testing infrastructure in developing speciation profiles. The uncertainty of the PM_2.5 species fraction in each profile is quantified using sampling survey analysis methods. The primary use of the profiles is to develop PM_2.5 emissions inventories for the United States, but the profiles may also be used in source apportionment, atmospheric modeling, and exposure assessment, and as a basis for light-duty gasoline emission profiles for countries with limited data.

Implications: PM_2.5 speciation profiles were developed from a large sample of light-duty gasoline vehicles tested in the Kansas City area. Separate PM_2.5 profiles represent cold start and hot stabilized running emission processes to distinguish important differences in chemical composition. Statistical analysis was used to construct profiles that represent PM_2.5 emissions from the U.S. vehicle fleet based on vehicles tested from the 2005 calendar year Kansas City metropolitan area. The profiles have been incorporated into the EPA MOVES emissions model, as well as the EPA SPECIATE database, to improve emission inventories and provide the PM_2.5 chemical characterization needed by CMAQv5.0 for atmospheric chemistry modeling.     

Dynamics of Bacterial Abundance,Biomass, Activity,and Community Composition in the Oligotrophic Traunsee and the Traun River (Austria)

The holomictic Traunsee is the deepest and second largest lakein Austria. The special characteristic of this ecosystem isthe fact that local salt and soda industries presumably alterthe lake by the discharge of waste materials. Since thebeginning of the 20th century salt and soda works areannually releasing up to 50,000 tons of solid wastes and up to150,000 tons of chloride into Traunsee. To assess potentialeffects of these anthropogenic impacts on the bacterioplanktonthree sampling sites, influenced as well as not influenced bythe industrial discharge, were chosen for comparison andsampled monthly from November 1997 to October 1998. Bacterialabundance ranged between 0.4 to 3.0 × 10⁶ cells ml^-1 with decreasing numbers along the depth profile. Theproportion of actively respiring bacteria, i.e. INT [2-(4-iodophenyl)-3-(4-nitrophenyl)-5-phenyltetrazolium chloride]reducing cells, never exceeded 10% of DAPI (4',6'-diamidino-2-phenylindole) stained cells. Fluorescence in situ hybridization (FISH) was used to examine the seasonal and spatial distribution of dominant phylogenetic groups of thebacterioplankton. Up to 84% of bacteria detected with DAPIcould be detected via FISH applying the universal bacterialprobe EUB338. Percentages of alpha- and beta-Proteobacteriaand members of the Cytophaga-Flavobacterium cluster did notexceed 60% of DAPI-stained cells.Beta-Proteobacteriaappeared to be the most abundant group, not only in Traunsee butalso in two reference lakes, Attersee and Hallstättersee. No significant differences in any of the bacterial parameters couldbe detected between the three sampling sites and all measurementswere found in the range reported for oligotrophic lakes. The highdischarge of the Traun River, resulting in a lake water renewaltime of only one year, may diminish possible effects of industrial waste discharge in the pelagic zone.     

Protozooplankton in the Deep Oligotrophic Traunsee (Austria) Influenced by Discharges of Soda and Salt Industries

Traunsee is a deep oligotrophic lake in Austria characterised by an artificial enrichment of chloride in the hypolimnion (up to 170 mg L^-1) caused by waste disposal of soda and salt industries. Protists were collected monthly over one year, observed alive and after Quantitative Protargol Staining (ciliates) or via epifluorescence microscopy (heterotrophic flagellates). Three sites within the lake (0–40 m depths) were compared to deeper water layers from 60–160 m depths where chloride concentrations and conductivity were increased. In addition, we observed the protozooplankton of two neighbouring lakes, i.e. reference systems, during one sampling occasion. In Traunsee the abundance of ciliates was low (200–36 600 cells L^-1) in contrast to high species diversity (at least 60 different species; H_S = 2.6) throughout the year. The main pelagic species in terms of abundance were small oligotrichs and prostomatids like Rimostrombidium brachykinetum/hyalinum, Balanion planctonicum and Urotricha spp. throughout the investigation period. Among free-living heterotrophic flagellates, which occurred at densities of 40–2800 cells mL^-1, small morphotypes dominated in the pelagial. No differences at the community level between the three lakes could be observed and pelagic ciliates and flagellates seemed not to be affected by increased chloride concentrations or by enhanced conductivity.     

Family–work conflict and job performance: A diary study of boundary conditions and mechanisms

In this study, we used a within‐person daily research paradigm to examine the relationship between daily family–work conflict (FWC) and daily job performance. On the basis of theory on dynamic behavior, we hypothesized that concentration serves as a mechanism through which daily FWC impairs daily job performance. We further predicted that psychological detachment from work during time‐off (i.e., mentally switching off) buffers the negative relationship between daily FWC and daily job performance. Ninety‐five employees completed daily surveys over one workweek. Multilevel modeling results showed that daily FWC was negatively associated with daily job performance and that concentration mediated this relationship. Furthermore, general psychological detachment, but not daily psychological detachment, buffered the negative relationship between daily FWC and daily job performance. The current findings suggest that daily FWC has negative performance implications and that the general level rather than the daily level of psychological detachment from work helps alleviate the negative implications. Copyright © 2013 John Wiley & Sons, Ltd.     

The acanthocephalan Paratenuisentis ambiguus as a sensitive indicator of the precious metals Pt and Rh from automobile catalytic converters

Recent studies revealed that intestinal acanthocephalans of fish can accumulate heavy metals to concentrations orders of magnitude higher than those in the host tissues or the aquatic environment. This significant heavy metal accumulation by acanthocephalans, even surpassing that of established free living accumulation bioindicators, encouraged us to study the bioavailability of the platinum-group-metals (PGM) Pt and Rh for parasites. These precious metals are used in catalytic converters of cars for exhaust gas purification in Europe since the early 1980s. In addition to the beneficial effect in reducing the emission of CHx, CO and NOx of cars there is an increasing emission of these metals. However, it still remains unclear if these elements become accumulated in the biosphere and whether they affect the health of organisms. The present study reveals that in European eels (Anguilla anguilla) naturally infected with the eoacanthocephalan parasite Paratenuisentis ambiguus and experimentally exposed to ground catalytic converter material, the parasites take up and accumulate the catalytic active metals Pt and Rh whereas in the examined host tissues we found no metal uptake. Compared with the PGM concentrations in the water the worms contained 1600 times higher Rh and 50 times higher Pt concentrations. Thus, the parasites can be used as sentinel organisms reflecting even very low levels of precious metals.     

Psychological Approaches to OSH Research—An Evaluation of 20 Years of Psychological Research on Industrial Safety and Health in Germany

During the past 20 years of research in occupational safety and health (OSH), major contributions have been made by psychology in general, foremost German work and organizational psychology. This is the result of an empirical study with 216 scientific projects that were analyzed by content, and 32 interviews on OSH with experts on science, as well as in professional occupations and federations. Its sound methodological and theoretical approach has helped work and organizational psychology to embody itself as a driving force of OSH. The research focuses on the development of tools for job analysis, striving for the valid diagnosis of occupational hazards and mental load. Consequently, work and organizational psychology provides a solid foundation for deriving human and personality ameliorating organizational measures. Among the predominant means of intervention are training in coping with stress, behavioral training and modeling, health circles, and the arrangement of environments sensitive to occupational load. Major deficits in the field of research show up within evaluation and transfer as well as within quality control of the developed diagnostic and devices regarding intervention. Future scientific effort by means of application-orientated methods is vital to detect and overcome effectively a mounting mental load in the occupational world.     

Disinfection of surfaces by photocatalytic oxidation with titanium dioxide and UVA light

Particularly in microbiological laboratories and areas in intensive medical use, regular and thorough disinfection of surfaces is required in order to reduce the numbers of bacteria and to prevent bacterial transmission. The conventional methods of disinfection with wiping are not effective in the longer term, cannot be standardized, are time- and staff-intensive and use aggressive chemicals. Disinfection with hard ultraviolet C (UVC) light is usually not satisfactory, as the depth of penetration is inadequate and there are occupational medicine risks. Photocatalytic oxidation on surfaces coated with titanium dioxide (TiO2) might offer a possible alternative. In the presence of water and oxygen, highly reactive OH-radicals are generated by TiO2 and mild ultraviolet A (UVA). These radicals are able to destroy bacteria, and may therefore be effective in reducing bacterial contamination. Direct irradiation with UVC however can produce areas of shadow in which bacteria are not inactivated. Using targeted light guidance and a light-guiding sheet (out of a UVA-transmittant, Plexiglas, for example), as in the method described in the present study, bacterial inactivation over the entire area is possible. The effectiveness of the method was demonstrated using bacteria relevant to hygiene such as Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Enterococcus faecium. For these bacteria, a reduction efficiency (RE) more than 6log10 steps in 60 min was observed. Using Candida albicans, a RE of 2log10 steps in 60 min was seen. Light and scanning electron microscopic examinations suggest that the germ destruction achieved takes place through direct damage to cell walls caused by OH-radicals.     

Thermodynamic modelling of bio-species accommodation

An ecological model has been constructed. A chemical analogy to the biological system has been developed, and the system's driving forces have been identified.     

Assessment of the Ecological Integrity of Traunsee (Austria) Via Analysis of Sediments and Benthic Microbial Communities

Since nearly one hundred years Traunsee experiences the import of tons of liquid and solid waste originating from salt and soda production. Today, the lake exhibits chloride concentrations of up to 170 mg L^-1 and 19% of the lake floor are directly or indirectly influenced by industrial deposits (ID). Based on the comparison of several microbial parameters in unaffected, directly affected and intermediate lake bottom sediments, the ecological integrity of the lake was evaluated. The highly alkaline ID, which were exclusively colonized by microorganisms, harbored a bacterial community reduced by a factor of 10 in abundance and biomass compared to undisturbed sediment areas within the lake. The bacterial community of ID was furthermore characterized by a reduced content of actively respiring cells (INT-formazan reduction), a lower frequency of dividing cells (FDC) and a significantly reduced cell and biomass production. A 80 to 90% reduction in carbon recycling is estimated for the area exclusively covered by ID. Protists, although occasionally absent from the industrial sediments, were in general found to be less sensitive to the contaminant stress. Differences in alkalinity and dissolved organic carbon (DOC) concentrations of sediment porewaters as well as the total organic content and C/N ratios of sediments partly explain the microbial pattern observed at the various sampling sites. Possible consequences of the continuous industrial tailings for the whole lake ecosystem and the validation of the ecological integrity are discussed.