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Vertical emission profiles for Europe based on plume rise calculations
2011
Bieser, J. | Aulinger, A. | Matthias, V. | Quante, M. | Denier van der Gon, H.A.C.
The vertical allocation of emissions has a major impact on results of Chemistry Transport Models. However, in Europe it is still common to use fixed vertical profiles based on rough estimates to determine the emission height of point sources. This publication introduces a set of new vertical profiles for the use in chemistry transport modeling that were created from hourly gridded emissions calculated by the SMOKE for Europe emission model. SMOKE uses plume rise calculations to determine effective emission heights. Out of more than 40 000 different vertical emission profiles 73 have been chosen by means of hierarchical cluster analysis. These profiles show large differences to those currently used in many emission models. Emissions from combustion processes are released in much lower altitudes while those from production processes are allocated to higher altitudes. The profiles have a high temporal and spatial variability which is not represented by currently used profiles.
اظهر المزيد [+] اقل [-]Source, concentration, and distribution of elemental mercury in the atmosphere in Toronto, Canada
2011
Cairns, Elaine | Tharumakulasingam, Kavitharan | Athar, Makshoof | Yousaf, Muhammad | Cheng, Irene | Huang, Y. | Lu, Julia | Yap, Dave
Atmospheric gaseous elemental mercury [GEM] at 1.8, 4, and 59 m above ground, in parking lots, and in indoor and outdoor air was measured in Toronto City, Canada from May 2008–July 2009. The average GEM value at 1.8 m was 1.89 ± 0.62 ng m⁻³. The GEM values increased with elevation. The average GEM in underground parking lots ranged from 1.37 to 7.86 ng m⁻³ and was higher than those observed from the surface parking lots. The GEM in the indoor air ranged from 1.21 to 28.50 ng m⁻³, was higher in the laboratories than in the offices, and was much higher than that in the outdoor air. All these indicate that buildings serve as sources of mercury to the urban atmosphere. More studies are needed to estimate the contribution of urban areas to the atmospheric mercury budget and the impact of indoor air on outdoor air quality and human health.
اظهر المزيد [+] اقل [-]Water, heat, and airborne pollutants effects on transpiration of urban trees
2011
Wang, Hua | Ouyang, Z. (Zhiyun) | Chen, Weiping | Wang, Xiaoke | Zheng, Hua | Ren, Yufen
Transpiration rates of six urban tree species in Beijing evaluated by thermal dissipation method for one year were correlated to environmental variables in heat, water, and pollutant groups. To sort out colinearity of the explanatory variables, their individual and joint contributions to variance of tree transpiration were determined by the variation and hierarchical partitioning methods. Majority of the variance in transpiration rates was associated with joint effects of variables in heat and water groups and variance due to individual effects of explanatory group were in comparison small. Atmospheric pollutants exerted only minor effects on tree transpiration. Daily transpiration rate was most affected by air temperature, soil temperature, total radiation, vapor pressure deficit, and ozone. Relative humidity would replace soil temperature when factors influencing hourly transpiration rate was considered.
اظهر المزيد [+] اقل [-]Root porosity and radial oxygen loss related to arsenic tolerance and uptake in wetland plants
2011
Li, H. | Ye, Z.H. | Wei, Z.J. | Wong, M.H.
The rates of radial oxygen loss (ROL), root porosity, concentrations of arsenic (As), iron (Fe) and manganese (Mn) in shoot and root tissues and on root surfaces, As tolerances, and their relationships in different wetland plants were investigated based on a hydroponic experiment (control, 0.8, 1.6mg AsL⁻¹) and a soil pot trail (control, 60mg Askg⁻¹). The results revealed that wetland plants showed great differences in root porosity (9–64%), rates of ROL (55–1750mmo1 O₂kg⁻¹ root d.w.d⁻¹), As uptake (e.g., 8.8–151mgkg⁻¹ in shoots in 0.8mg AsL⁻¹ treatment), translocation factor (2.1–47% in 0.8mg AsL⁻¹) and tolerance (29–106% in 0.8mg AsL⁻¹). Wetland plants with higher rates of ROL and root porosity tended to form more Fe/Mn plaque, possess higher As tolerance, higher concentrations of As on root surfaces and a lower As translocation factor so decreasing As toxicity.
اظهر المزيد [+] اقل [-]Plant communities in relation to flooding and soil contamination in a lowland Rhine River floodplain
2011
Schipper, Aafke M. | Lotterman, Kim | Leuven, Rob S.E.W. | Ragas, Ad M.J. | Kroon, Hans de | Hendriks, A Jan
Using canonical correspondence analysis (CCA), relationships were investigated between plant species composition and flooding characteristics, heavy metal contamination and soil properties in a lowland floodplain of the Rhine River. Floodplain elevation and yearly average flooding duration turned out to be more important for explaining variation in plant species composition than soil heavy metal contamination. Nevertheless, plant species richness and diversity showed a significant decrease with the level of contamination. As single heavy metal concentrations seemed mostly too low for causing phytotoxic effects in plants, this trend is possibly explained by additive effects of multiple contaminants or by the concomitant influences of contamination and non-chemical stressors like flooding. These results suggest that impacts of soil contamination on plants in floodplains could be larger than expected from mere soil concentrations. In general, these findings emphasize the relevance of analyzing effects of toxic substances in concert with the effects of other relevant stressors.
اظهر المزيد [+] اقل [-]Temporal genetic variability and host sources of Escherichia coli associated with fecal pollution from domesticated animals in the shellfish culture environment of Xiangshan Bay, East China Sea
2011
Fu, Ling-Lin | Shuai, Jiang-Bing | Wang, Yanbo | Ma, Hong-Jia | Li, Jian Rong
This study was conducted to analyze the genetic variability of Escherichia coli from domesticated animal wastes for microbial source tracking (MST) application in fecal contaminated shellfish growing waters of Xiangshan Bay, East China Sea. (GTG)₅ primer was used to generate 1363 fingerprints from E. coli isolated from feces of known 9 domesticated animal sources around this shellfish culture area. Jackknife analysis of the complete (GTG)₅-PCR DNA fingerprint library indicated that isolates were assigned to the correct source groups with an 84.28% average rate of correct classification. Based on one-year source tracking data, the dominant sources of E. coli were swine, chickens, ducks and cows in this water area. Moreover, annual and spatial changes of E. coli concentrations and host sources may affect the level and distribution of zoonotic pathogen species in waters. Our findings will further contribute to preventing fecal pollution in aquatic environments and quality control of shellfish.
اظهر المزيد [+] اقل [-]Open Air Laboratories (OPAL): A community-driven research programme
2011
Davies, L. | Bell, J.N.B. | Bone, J. | Creagh-Henry, M. (May) | Hill, L. | Howard, C. | Hobbs, S.J. | Jones, D.T. | Power, S.A. | Rose, N. | Ryder, C. | Seed, L. | Stevens, G. | Toumi, R. | Voulvoulis, N. | White, P.C.L.
OPAL is an English national programme that takes scientists into the community to investigate environmental issues. Biological monitoring plays a pivotal role covering topics of: i) soil and earthworms; ii) air, lichens and tar spot on sycamore; iii) water and aquatic invertebrates; iv) biodiversity and hedgerows; v) climate, clouds and thermal comfort. Each survey has been developed by an inter-disciplinary team and tested by voluntary, statutory and community sectors. Data are submitted via the web and instantly mapped. Preliminary results are presented, together with a discussion on data quality and uncertainty. Communities also investigate local pollution issues, ranging from nitrogen deposition on heathlands to traffic emissions on roadside vegetation. Over 200,000 people have participated so far, including over 1000 schools and 1000 voluntary groups. Benefits include a substantial, growing database on biodiversity and habitat condition, much from previously unsampled sites particularly in urban areas, and a more engaged public.
اظهر المزيد [+] اقل [-]Floodplain methylmercury biomagnification factor higher than that of the contiguous river (South River, Virginia USA)
2011
Newman, Michael C. | Xu, Xiaoyu | Condon, Anne | Liang, Lian
Mercury biomagnification on the South River floodplain (Virginia, USA) was modeled at two locations along a river reach previously modeled for methylmercury movement through the aquatic trophic web. This provided an opportunity to compare biomagnification in adjoining trophic webs. Like the aquatic modeling results, methylmercury-based models provided better prediction than those for total mercury. Total mercury Food Web Magnification Factors (FWMF, fold per trophic level) for the two locations were 4.9 and 9.5. Methylmercury FWMF for the floodplain locations were higher (9.3 and 25.1) than that of the adjacent river (4.6). Previous speculation was not resolved regarding whether the high mercury concentrations observed in floodplain birds was materially influenced by river prey consumption by riparian spiders and subsequent spider movement into the trophic web of the adjacent floodplains. Results were consistent with a gradual methylmercury concentration increase from contaminated floodplain soil, to arthropod prey, and finally, to avian predators.
اظهر المزيد [+] اقل [-]Variations in concentrations and compositions of polycyclic aromatic hydrocarbons (PAHs) in coals related to the coal rank and origin
2011
Laumann, S. | Micić, V. | Kruge, M.A. | Achten, C. | Sachsenhofer, R.F. | Schwarzbauer, J. | Hofmann, T.
The release of unburnt coal particles and associated polycyclic aromatic hydrocarbons (PAHs) may cause adverse impacts on the environment. This study assessed variations in the concentration and composition of PAHs in a set of fifty coal samples from eleven coal basins worldwide. The maximum PAH concentrations at high volatile bituminous rank were recorded in samples from a single basin. Considering the entire sample set, the highest PAH concentrations were in fact found outside of this rank range, suggesting that the maceral composition and thus the coal’s origin also influenced PAH concentrations. The examination of the PAH compositions revealed that alkylated 2–3 ring PAHs remain dominant compounds irrespective of coal rank or origin. Multivariate analysis based on PAH and maceral content, bulk and maturity parameters allowed the recognition of seven groups with different rank and origin within the coal sample set.
اظهر المزيد [+] اقل [-]Assessment of the environmental persistence and long-range transport of endosulfan
2011
Becker, Linus | Scheringer, Martin | Schenker, Urs | Hungerbühler, Konrad
Concentrations of the insecticide endosulfan (α- and β-isomer) and its degradation product endosulfan sulfate in air, seawater and soil are calculated with the global environmental fate model CliMoChem. As model input, physicochemical properties of all three compounds were assembled and a latitudinally and temporally resolved emission inventory was generated. For concentrations in air, model and measurements are in good agreement; a bimodal seasonality with two peaks in spring and fall as it is observed in Arctic air is reproduced by the model. For seawater, the agreement of model and measurements depends on the values of the hydrolysis activation energy of endosulfan used in the model; with relatively high values around 100kJ/mol, model results match field data well. The results of this assessment of the levels, persistence, and global distribution of endosulfan are also relevant for the evaluation of endosulfan as a Persistent Organic Pollutant under the Stockholm Convention.
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