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Результаты 281-290 из 1,310
Incidence of polybrominated diphenyl ethers in central air conditioner filter dust from a new office building Полный текст
2011
Ni, Hong-Gang | Cao, Shan-Ping | Chang, Wen-Jing | Zeng, Hui
This study examined polybrominated diphenyl ethers (PBDEs) in central air conditioner filter (CACF) dust from a new office building in Shenzhen, China. Human exposure to PBDE via dust inhalation and ingestion were also estimated. PBDEs level in CACF dust was lower than those in the other countries and regions. Approximately 0.671 pg/kg bw/day PM₂.₅ (Particulate Matter up to 2.5 μm in size) bounded Σ₁₅PBDEs can be inhaled deep into the lungs and 4.123 pg/kg bw/day PM₁₀ (Particulate Matter up to 10 μm in size) bounded Σ₁₅PBDEs tend to be deposited in the upper parts of the respiratory system. The average total intake of Σ₁₅PBDEs via dust inhalation and ingestion for adults reached ∼141 pg/kg bw/day in this building. This value was far below the reference dose (RfD) recommended by United States Environmental Protection Agency. Human exposure to PBDEs via dust inhalation and ingestion in the new building is less than the old ones.
Показать больше [+] Меньше [-]Urban and rural mortality rates during heat waves in Berlin and Brandenburg, Germany Полный текст
2011
Gabriel, Katharina M.A. | Endlicher, Wilfried R.
In large cities such as Berlin, human mortality rates increase during intense heat waves. Analysis of relevant data from north-eastern Germany revealed that, during the heat waves that occurred between 1990 and 2006, health risks were higher for older people in both rural and urban areas, but that, during the two main heat waves within that 17-year period of time, the highest mortality rates were from the city of Berlin, and in particular from its most densely built-up districts. Adaptation measures will need to be developed, particularly within urban areas, in order to cope with the expected future intensification of heat waves due to global climate change.
Показать больше [+] Меньше [-]Urban nonpoint source pollution buildup and washoff models for simulating storm runoff quality in the Los Angeles County Полный текст
2011
Wang, Long | Wei, Jiahua | Huang, Yuefei | Wang, Guangqian | Maqsood, Imran
Many urban nonpoint source pollution models utilize pollutant buildup and washoff functions to simulate storm runoff quality of urban catchments. In this paper, two urban pollutant washoff load models are derived using pollutant buildup and washoff functions. The first model assumes that there is no residual pollutant after a storm event while the second one assumes that there is always residual pollutant after each storm event. The developed models are calibrated and verified with observed data from an urban catchment in the Los Angeles County. The application results show that the developed model with consideration of residual pollutant is more capable of simulating nonpoint source pollution from urban storm runoff than that without consideration of residual pollutant. For the study area, residual pollutant should be considered in pollutant buildup and washoff functions for simulating urban nonpoint source pollution when the total runoff volume is less than 30mm.
Показать больше [+] Меньше [-]Differential accumulation of mercury and other trace metals in the food web components of a reservoir impacted by a chlor-alkali plant (Flix, Ebro River, Spain): Implications for biomonitoring Полный текст
2011
Soto, David X. | Roig, Romero | Gacia, Esperança | Catalan, Jordi
Comparative studies of biomonitors of trace metal contamination are relatively scarce. We took advantage of a point source pollution in a reservoir (Flix, Spain) to compare trace metal (Hg, Pb, Cd, Se, As, Zn, Cu, Cr) bioaccumulation patterns among 16 food web components. Our results indicate that most organisms are suitable for Hg biomonitoring, whereas other metals are better monitored by only some of them. Biofilms and zebra mussel were the organisms with larger and more diverse biomonitoring capacity. However, we show that using groups of biomonitors increase the scope and strengths of the conclusions and specific goals can be better addressed. We conclude providing an overview of the strengths and weaknesses of the main organisms considered for biomonitoring trace metals in rivers and reservoirs.
Показать больше [+] Меньше [-]Ecological risk assessment of heavy metals in sediment and human health risk assessment of heavy metals in fishes in the middle and lower reaches of the Yangtze River basin Полный текст
2011
Yi, Yujun | Yang, Zhifeng | Zhang, Shanghong
The concentrations of heavy metals (Cr, Cd, Hg, Cu, Zn, Pb and As) in the water, sediment, and fish were investigated in the middle and lower reaches of the Yangtze River, China. Potential ecological risk analysis of sediment heavy metal concentrations indicated that six sites in the middle reach, half of the sites in the lower reach, and two sites in lakes, posed moderate or considerable ecological risk. Health risk analysis of individual heavy metals in fish tissue indicated safe levels for the general population and for fisherman but, in combination, there was a possible risk in terms of total target hazard quotients. Correlation analysis and PCA found that heavy metals (Hg, Cd, Pb, Cr, Cu, and Zn) may be mainly derived from metal processing, electroplating industries, industrial wastewater, and domestic sewage. Hg may also originate from coal combustion. Significant positive correlations between TN and As were observed.
Показать больше [+] Меньше [-]Binational school-based monitoring of traffic-related air pollutants in El Paso, Texas (USA) and Ciudad Juárez, Chihuahua (México) Полный текст
2011
Raysoni, Amit U. | Sarnat, Jeremy A. | Sarnat, Stefanie Ebelt | García, José Humberto | Holguin, Fernando | Flores-Luevano, Silvia | Li, Wen-Whai
Paired indoor and outdoor concentrations of fine and coarse particulate matter (PM), PM2.5 reflectance [black carbon(BC)], and nitrogen dioxide (NO₂) were determined for sixteen weeks in 2008 at four elementary schools (two in high and two in low traffic density zones) in a U.S.–Mexico border community to aid a binational health effects study. Strong spatial heterogeneity was observed for all outdoor pollutant concentrations. Concentrations of all pollutants, except coarse PM, were higher in high traffic zones than in the respective low traffic zones. Black carbon and NO₂ appear to be better traffic indicators than fine PM. Indoor air pollution was found to be well associated with outdoor air pollution, although differences existed due to uncontrollable factors involving student activities and building/ventilation configurations. Results of this study indicate substantial spatial variability of pollutants in the region, suggesting that children’s exposures to these pollutants vary based on the location of their school.
Показать больше [+] Меньше [-]The impact of nitrogen deposition on acid grasslands in the Atlantic region of Europe Полный текст
2011
Stevens, Carly J. | Duprè, Cecilia | Dorland, Edu | Gaudnik, Cassandre | Gowing, David J.G. | Bleeker, Albert | Diekmann, Martin | Alard, Didier | Bobbink, Roland | Fowler, David | Corcket, Emmanuel | Mountford, J Owen | Vandvik, Vigdis | Aarrestad, Per Arild | Muller, Serge | Dise, Nancy B.
The impact of nitrogen deposition on acid grasslands in the Atlantic region of Europe Полный текст
2011
Stevens, Carly J. | Duprè, Cecilia | Dorland, Edu | Gaudnik, Cassandre | Gowing, David J.G. | Bleeker, Albert | Diekmann, Martin | Alard, Didier | Bobbink, Roland | Fowler, David | Corcket, Emmanuel | Mountford, J Owen | Vandvik, Vigdis | Aarrestad, Per Arild | Muller, Serge | Dise, Nancy B.
A survey of 153 acid grasslands from the Atlantic biogeographic region of Europe indicates that chronic nitrogen deposition is changing plant species composition and soil and plant-tissue chemistry. Across the deposition gradient (2–44 kg N ha⁻¹ yr⁻¹) grass richness as a proportion of total species richness increased whereas forb richness decreased. Soil C:N ratio increased, but soil extractable nitrate and ammonium concentrations did not show any relationship with nitrogen deposition. The above-ground tissue nitrogen contents of three plant species were examined: Agrostis capillaris (grass), Galium saxatile (forb) and Rhytidiadelphus squarrosus (bryophyte). The tissue nitrogen content of neither vascular plant species showed any relationship with nitrogen deposition, but there was a weak positive relationship between R. squarrosus nitrogen content and nitrogen deposition. None of the species showed strong relationships between above-ground tissue N:P or C:N and nitrogen deposition, indicating that they are not good indicators of deposition rate.
Показать больше [+] Меньше [-]The impact of nitrogen deposition on acid grasslands in the Atlantic region of Europe Полный текст
2011
Stevens, Carly J. | Dupre, Cecilia | Dorland, Edu | Gaudnik, Cassandre | Gowing, David J.G. | Bleeker, Albert | Diekmann, Martin | Alard, Didier | Bobbink, Roland | Fowler, David | Corcket, Emmanuel | Mountford, J. Owen | Vandvik, Vigdis | Aarrestad, Per Arild | Muller, Serge | Dise, Nancy B. | Open University | Lancaster Environment Centre ; Lancaster University | Universität Bremen [Deutschland] = University of Bremen [Germany] = Université de Brême [Allemagne] | Universiteit Utrecht / Utrecht University [Utrecht] | Biodiversité, Gènes & Communautés (BioGeCo) ; Institut National de la Recherche Agronomique (INRA)-Université de Bordeaux (UB) | Energy Research Centre of the Netherlands (ECN) | Radboud University [Nijmegen] | Natural Environment Research Council (NERC) | Department of Biology ; University of Washington [Seattle] | Norwegian Institute for Nature Research (NINA) | Université Paul Verlaine - Metz (UPVM) | Manchester Metropolitan University (MMU) | European Science Foundation; DfG (Germany); NERC (United Kingdom); NWO (The Netherlands); INRA; ADEME; Aquitaine Region (France)
International audience | A survey of 153 acid grasslands from the Atlantic biogeographic region of Europe indicates that chronic nitrogen deposition is changing plant species composition and soil and plant-tissue chemistry. Across the deposition gradient (2–44 kg N ha−1 yr−1) grass richness as a proportion of total species richness increased whereas forb richness decreased. Soil C:N ratio increased, but soil extractable nitrate and ammonium concentrations did not show any relationship with nitrogen deposition. The above-ground tissue nitrogen contents of three plant species were examined: Agrostis capillaris (grass), Galium saxatile (forb) and Rhytidiadelphus squarrosus (bryophyte). The tissue nitrogen content of neither vascular plant species showed any relationship with nitrogen deposition, but there was a weak positive relationship between R. squarrosus nitrogen content and nitrogen deposition. None of the species showed strong relationships between above-ground tissue N:P or C:N and nitrogen deposition, indicating that they are not good indicators of deposition rate.
Показать больше [+] Меньше [-]Seabird feathers as monitors of the levels and persistence of heavy metal pollution after the Prestige oil spill Полный текст
2011
Moreno, Rocío | Jover, Lluís | Diez, Carmen | Sanpera, Carola
We measured heavy metal concentrations in yellow-legged gulls (n = 196) and European shags (n = 189) in order to assess the temporal pattern of contaminant exposure following the Prestige oil spill in November 2002. We analysed Pb, Cu, Zn, Cr, Ni and V levels in chick feathers sampled at four colonies during seven post-spill years (2003–2009), and compared results with pre-spill levels obtained from feathers of juvenile shag corpses (grown in spring/summer 2002). Following the Prestige wreck, Cu (4.3–10 μg g⁻¹) and Pb concentrations (1.0–1.4 μg g⁻¹) were, respectively, between two and five times higher than pre-spill levels (1.5–3.6 and 0.1–0.4 μg g⁻¹), but returned to previous background concentrations after three years. Our study highlights the suitability of chick feathers of seabirds for assessing the impact of oil spills on heavy metal contamination, and provides the best evidence to date on the persistence of oil pollution after the Prestige incident.
Показать больше [+] Меньше [-]Assessing the diurnal variability of pharmaceutical and personal care products in a full-scale activated sludge plant Полный текст
2011
Salgado, R. | Marques, R. | Noronha, J.P. | Mexia, J.T. | Carvalho, G. | Oehmen, A. | Reis, M.A.M.
An intensive sampling campaign has been carried out in a municipal wastewater treatment plant (WWTP) to assess the dynamics of the influent pharmaceutical active compounds (PhAC) and musks. The mass loadings of these compounds in wastewater influents displayed contrasting diurnal variations depending on the compound. The musks and some groups of PhACs tended to follow a similar diurnal trend as compared to macropollutants, while the majority of PhACs followed either the opposite trend or no repeatable trend. The total musk loading to the WWTP was 0.74±0.25gd⁻¹, whereas the total PhAC mass loading was 84.7±63.8gd⁻¹. Unlike the PhACs, the musks displayed a high repeatability from one sampling day to the next. The range of PhAC loadings in the influent to WWTPs can vary several orders of magnitude from one day or week to the next, representing a challenge in obtaining data for steady-state modelling purposes.
Показать больше [+] Меньше [-]Mobile passive samplers: Concept for a novel mode of exposure Полный текст
2011
Allan, Ian J. | Nilsson, Hans C. | Tjensvoll, Ingrid | Bradshaw, Clare | Næs, Kristoffer
Integrative passive sampling with devices such as semipermeable membrane devices generally relies on rigs for month-long static exposures in water. We evaluate here whether mobile exposures of passive samplers can provide reliable estimates of dissolved contaminant concentrations. Mobile exposures were obtained by towing samplers fastened to the end of a benthic trawl net. Significant and reproducible absorption of polycyclic aromatic hydrocarbons during 5 h-long deployments was made possible by high sampling rates resulting from high water turbulences during towing at 1.2–1.5 knots. Sampling rates (72–215 L d⁻¹) estimated from the dissipation of performance reference compounds were supported by in situ calibration with samplers exposed for a 30 days in the vicinity of the test site. Higher fluoranthene and pyrene absorption in samplers exposed to the trawling-induced sediment plume could be attributed to desorption from re-suspended sediments. This mode of exposure has the potential to be used in monitoring programmes.
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