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Potential for reducing air-pollutants while achieving 2 °C global temperature change limit target Texto completo
2014
Hanaoka, Tatsuya | Akashi, Osamu | Fujiwara, Kazuya | Motoki, Yuko | Hibino, Go
This study analyzes the potential to reduce air pollutants while achieving the 2 °C global temperature change limit target above pre-industrial levels, by using the bottom-up optimization model, AIM/Enduse[Global]. This study focuses on; 1) estimating mitigation potentials and costs for achieving 2 °C, 2.5 °C, and 3 °C target scenarios, 2) assessing co-benefits of reducing air pollutants such as NOx, SO2, BC, PM, and 3) analyzing features of sectoral attributions in Annex I and Non-Annex I groups of countries. The carbon tax scenario at 50 US$/tCO2-eq in 2050 can reduce GHG emissions more than the 3 °C target scenario, but a higher carbon price around 400 US$/tCO2-eq in 2050 is required to achieve the 2 °C target scenario. However, there is also a co-benefit of large reduction potential of air pollutants, in the range of 60–80% reductions in 2050 from the reference scenario while achieving the 2 °C target.
Mostrar más [+] Menos [-]Lead and other elements in house dust of Japanese residences – Source of lead and health risks due to metal exposure Texto completo
2014
Yoshinaga, Jun | Yamasaki, Kumiko | Yonemura, Ayumi | Ishibashi, Yuri | Kaido, Takaya | Mizuno, Kodai | Takagi, Mai | Tanaka, Atsushi
The levels of 25 elements in house dust collected from 100 general Japanese residences were measured. Factor analysis was applied on the multi-element data to explore source of Pb (median concentration 49.1 mg/kg) in house dust. Six factors were extracted and Pb was found to have great loading on the fifth factor with Sb and Sn, suggesting solder (Sn), and plastic and metals (Sb) may be the sources of Pb in the house dust of Japanese residences. No significant loading was found on soil-related factors indicating non-significant contribution of Pb in track-in soil. Seven heavy metals (Cd, Cu, Mo, Pb, Sb, Sn, and Zn) were found in house dust at >10 times more condensed than crustal abundance. Health risk of these elements to children via the ingestion of house dust was estimated based on the comparison with tolerable daily intake and found to be non-significant for most of the elements.
Mostrar más [+] Menos [-]Synergistic role of different soil components in slow sorption kinetics of polar organic contaminants Texto completo
2014
Zhang, Dongmei | Hou, Lei | Zhu, Dongqiang | Chen, Wei
We observed that the sorption kinetics of nitrobenzene and 2,4-dinitrotoluene (two model polar compounds) was significantly slower than that of 1,4-dichlorobenzene and phenanthrene (two model apolar compounds). The difference was attributable to the strong non-hydrophobic interactions between the polar molecules and soil. Interestingly, sorption kinetics of the polar sorbates to the soil organic matter-free soil, humic/fulvic acid-free soil, and extracted humic acids was very fast, indicating that different soil components played a synergetic role in the observed slow kinetics. We propose that slow sorption kinetics of highly polar sorbates stems mainly from the strong specific interactions (H-bonding, electron donor–acceptor interactions, etc.) with humic/fulvic acids; such specific interactions occur when sorbate molecules diffuse through humic/fulvic acids coiled, in relatively compressed confirmations, within the complex, tortuous, and porous soil matrices formed by mineral grains/particles and soil organic matter.
Mostrar más [+] Menos [-]Field measurement on the emissions of PM, OC, EC and PAHs from indoor crop straw burning in rural China Texto completo
2014
Wei, Siye | Shen, Guofeng | Zhang, Yanyan | Xue, Miao | Xie, Han | Lin, Pengchuan | Chen, Yuanchen | Wang, Xilong | Tao, Shu
Field measurements were conducted to measure emission factors of particulate matter (EFPM), organic carbon (EFOC), elemental carbon (EFEC), 28 parent polycyclic aromatic hydrocarbons (EF28pPAHs), and 4 oxygenated PAHs (EF4oPAHs) for four types of crop straws burned in two stoves with similar structure but different ages. The average EFPM, EFOC, EFEC, EF28pPAHs, and EF4oPAHs were 9.1 ± 5.7 (1.8–22 as range), 2.6 ± 2.9 (0.30–12), 1.1 ± 1.2 (0.086–5.5), 0.26 ± 0.19 (0.076–0.96), 0.011 ± 0.14 (1.3 × 10−4 – 0.063) g/kg, respectively. Much high EF28pPAHs was observed in field compared with the laboratory derived EFs and significant difference in EF28pPAHs was identified among different crop residues, indicating considerable underestimation when laboratory derived EFs were used in the inventory. The field measured EFPM, EFOC, and EFEC were significantly affected by stove age and the EFs of carbonaceous particles for the 15-year old stove were approximately 2.5 times of those for the 1-year old stove.
Mostrar más [+] Menos [-]Transport of surfactant-facilitated multiwalled carbon nanotube suspensions in columns packed with sized soil particles Texto completo
2014
Lu, Yinying | Yang, Kun | Lin, Daohui
Transport of carbon nanotubes (CNTs) in soil/sediment matrixes can regulate their potential eco-effects and has been however rarely studied. Herein, column experiments were conducted to investigate mobility of CNT suspensions stabilized by dodecylbenzenesulfonic acid sodium salt (SDBS), octyl-phenol-ethoxylate (TX-100) and cetylpyridinium chloride (CPC) in four soil samples with certain particle sizes. Humic acid was extracted from a soil sample and was coated on quartz sands to explore the effect of soil organic matter (SOM) on the mobility. Results showed that the positively-charged CPC-CNT was entirely retained in the columns while the negatively-charged SDBS-CNT and TX-100-CNT more or less broke through the columns. Pearson correlation analyses revealed that soil texture rather than SOM controlled the mobility. Electrostatic attraction to and/or precipitation on the grain surfaces together with the straining effect could explain the CNT retention. These novel results will help to understand the eco-effects of CNTs.
Mostrar más [+] Menos [-]Population responses of Daphnia magna, Chydorus sphaericus and Asellus aquaticus in pesticide contaminated ditches around bulb fields Texto completo
2014
Ieromina, O. | Peijnenburg, W.J.G.M. | de Snoo, G.R. | Vijver, M.G.
The goal of this study was to investigate the effects of ambient concentrations of pesticides combined with abiotic factors on the key aquatic species Daphnia magna, Chydorus sphaericus and Asellus aquaticus by means of 21 days field exposure experiments. In situ bioassays were deployed in ditches around flower bulb fields during spring and autumn 2011–2012. The results showed that phosphate was the most variable parameter followed by pesticides expressed as toxic units, as the main factors explaining differences between sites. Variation in reproduction and growth of cladoceran D. magna was largely explained by nutrients, whereas dissolved oxygen contributed mostly to variations in reproduction of C. sphaericus. Dissolved organic carbon contributed to variations in growth of the detrivore A. aquaticus. It is concluded that abiotic stressors rather than pesticides contributed significantly to the performance of aquatic invertebrates.
Mostrar más [+] Menos [-]Canopy carbon budget of Siebold's beech (Fagus crenata) sapling under free air ozone exposure Texto completo
2014
Watanabe, Makoto | Hoshika, Yasutomo | Inada, Naoki | Koike, Takayoshi
To determine the effects of ozone (O3) on the canopy carbon budget, we investigated photosynthesis and respiration of leaves of Siebold's beech saplings under free air O3 exposure (60 nmol mol−1, during daytime) in relation to the within-canopy light gradient; we then calculated the canopy-level photosynthetic carbon gain (PCG) and respiratory carbon loss (RCL) using a canopy photosynthesis model. Susceptibilities of photosynthesis and respiration to O3 were greater in leaves of upper canopy than in the lower canopy. The canopy net carbon gain (NCG) was reduced by O3 by 12.4% during one growing season. The increased RCL was the main factor for the O3-induced reduction in NCG in late summer, while contributions of the reduced PCG and the increased RCL to the NCG were almost the same in autumn. These results indicate contributions of changes in PCG and RCL under O3 to NCG were different between seasons.
Mostrar más [+] Menos [-]Prevalence, antibiotic resistance patterns and molecular characterization of Escherichia coli from Austrian sandpits Texto completo
2014
Badura, Alexandra | Luxner, Josefa | Feierl, Gebhard | Reinthaler, Franz F. | Zarfel, Gernot | Galler, Herbert | Pregartner, Gudrun | Riedl, Regina | Grisold, Andrea J.
The aim was to determine the prevalence of E. coli and coliform bacteria in playground sand of all public children's sandpits in Graz (n = 45), Austria, and to assess the frequency of antimicrobial resistance in E. coli. Molecular characterization included the discrimination of O-serotypes and H-antigens and the determination of virulence and resistance genes, using a microarray technology. E. coli isolates were tested for susceptibility to a set of antibiotics by VITEK2 system and disk diffusion method. In total, 22 (49%) and 44 (98%) sandpits were positive for E. coli and coliform bacteria. Median concentrations of E. coli and coliform bacteria in the sand samples were: 2.6 × 104 CFU/100 g and 3.0 × 105 CFU/100 g. Resistance rates were: ampicillin, 12.5%; piperacillin, 10.4%; amoxicillin/clavulanic acid, 9.4%; cotrimoxazole, 6.3%; tetracycline, 6.3%; piperacillin/tazobactam, 5.2%. No ESBL- or carbapenemase-producing isolates were found. The most prevalent serogroups were O15, O6 and O4. Isolates harbored 0 up to 16 different virulence genes.
Mostrar más [+] Menos [-]Decreased rates of terpene emissions in Ornithopus compressus L. and Trifolium striatum L. by ozone exposure and nitrogen fertilization Texto completo
2014
Llusia, Joan | Bermejo-Bermejo, Victoria | Calvete-Sogo, Héctor | Peñuelas, Josep
Increasing tropospheric ozone (O3) and nitrogen soil availability (N) are two of the main drivers of global change. They both may affect gas exchange, including plant emission of volatiles such as terpenes. We conducted an experiment using open-top chambers to analyze these possible effects on two leguminous species of Mediterranean pastures that are known to have different O3 sensitivity, Ornithopus compressus and Trifolium striatum. O3 exposure and N fertilization did not affect the photosynthetic rates of O. compressus and T. striatum, although O3 tended to induce an increase in the stomatal conductance of both species, especially T. striatum, the most sensitive species. O3 and N soil availability reduced the emission of terpenes in O. compressus and T. striatum. If these responses are confirmed as a general pattern, O3 could affect the competitiveness of these species.
Mostrar más [+] Menos [-]Exposure of general population to PBDEs: A Progressive Total Diet Study in South Korea Texto completo
2014
Nguyen, Khanh-Hoang | Pyo, Heesoo | Kim, Jongchul | Shin, EunSu | Chang, Yoon Seok
This study assessed the level of 24 polybrominated diphenyl ethers (PBDEs) in Korean foods following a Progressive Total Diet Study (TDS). The experiments comprised 96 types of dietetically representative foods, all were either cooked or edible raw. PBDEs were widely encountered in foodstuffs with the highest concentration in plant oils, fishes and shellfishes. Of all congeners tested for, BDE-47 was the most predominant and encountered in almost all food items except meats. The presence of nona-BDEs at significant levels indicated that Korean environments are still contaminated by deca-BDE. The daily dietary intake of PBDEs was estimated to be 63 ng d−1. The highest PBDEs intake was observed in the 19–39 year old group and gradually decreased as age increased. Our study suggests that the TDS approach using foods in the table-ready form should be used for a better estimation of dietary exposure to PBDEs.
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