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Everyday exposure to power frequency magnetic fields and associations with non-specific physical symptoms Texto completo
2015
Bolte, John F.B. | Baliatsas, Christos | Eikelboom, Tessa | van Kamp, Irene
The aim of this study was to investigate the association between exposure to extremely low frequency magnetic fields (ELF MF), or power frequency fields, and non-specific physical symptoms (NSPS). In a cross-sectional study, personal exposure to ELF MF was measured for 99 adults selected in and around Amsterdam, the Netherlands in 2009–2010. They were scored on 16 NSPS. As a cut-off point for the individual 24-h time weighted average exposure the 80-percentile (0.09 μT) was chosen. As only one man scored “moderately high” on the somatisation scale against nine women, we decided to proceed analyses only with the 48 women. The crude odds ratio (OR) for women was 8.50 (CI 95%: 1.73–46.75), suggesting that for women environmental exposure to ELF MF is associated with an increased score on NSPS. As this is an exploratory cross-sectional study in a relatively small sample, no conclusions regarding causality can be drawn.
Mostrar más [+] Menos [-]Polychlorinated biphenyls and polybrominated biphenyl ethers in adipose tissue and matched serum from an E-waste recycling area (Wenling, China) Texto completo
2015
Lv, Quan-Xia | Wang, Wenyue | Li, Xing-Hong | Yu, Lianlian | Zhang, Yun | Tian, Yuan
To Date, the knowledge on relationship between PCBs/PBDEs exposure and thyroid hormones (THs) levels during pregnancy still needs to be extended. Meanwhile, studies on congener-specific adipose-serum ratios for PCBs/PBDEs were limited. This study reports the levels of PCBs/PBDEs in serum-adipose tissue samples (n = 64) from expectant women living surrounding e-waste recycling sites in Wenling, China. Their concentrations varied from several to hundreds of ng g−1 lipid. Maternal exposure to PCBs was associated with lower TSH during pregnancy, suggesting possible implication for maternal health and fetal development. The compound levels between the adipose tissue and matched serum samples were highly correlated (p < 0.001), generating a predicted adipose-serum partitioning relationship for individual PCB congener and PBDE congener. Molecular characteristics, such as Kow value, molecular weight and molecular volume, may play a key role in the variable partitioning of some compounds between serum and adipose tissue.
Mostrar más [+] Menos [-]Modelling the dispersion and transport of reactive pollutants in a deep urban street canyon: Using large-eddy simulation Texto completo
2015
Zhong, Jian | Cai, Xiao-Ming | Bloss, William James
This study investigates the dispersion and transport of reactive pollutants in a deep urban street canyon with an aspect ratio of 2 under neutral meteorological conditions using large-eddy simulation. The spatial variation of pollutants is significant due to the existence of two unsteady vortices. The deviation of species abundance from chemical equilibrium for the upper vortex is greater than that for the lower vortex. The interplay of dynamics and chemistry is investigated using two metrics: the photostationary state defect, and the inferred ozone production rate. The latter is found to be negative at all locations within the canyon, pointing to a systematic negative offset to ozone production rates inferred by analogous approaches in environments with incomplete mixing of emissions. This study demonstrates an approach to quantify parameters for a simplified two-box model, which could support traffic management and urban planning strategies and personal exposure assessment.
Mostrar más [+] Menos [-]Aggregation and resuspension of graphene oxide in simulated natural surface aquatic environments Texto completo
2015
Hua, Zulin | Tang, Zhiqiang | Bai, Xue | Zhang, Jianan | Yu, Lu | Cheng, Haomiao
A series of experiments were performed to simulate the environmental behavior and fate of graphene oxide nanoparticles (GONPs) involved in the surface environment relating to divalent cations, natural organic matter (NOM), and hydraulics. The electrokinetic properties and hydrodynamic diameters of GONPs was systematically determined to characterize GONPs stability and the results indicated Ca2+ (Mg2+) significantly destabilized GONPs with high aggregate strength factors (SF) and fractal dimension (FD), whereas NOM decreased aggregate SF with lower FD and improved GONPs stability primarily because of increasing steric repulsion and electrostatic repulsion. Furthermore, the GONPs resuspension from the sand bed into overlying water with shear flow confirmed that the release would be restricted by Ca2+ (Mg2+), however, enhanced by NOM. The interaction energy based on Derjaguin–Landau–Verwey–Overbeek theory verifies the aggregation and resuspension well. Overall, these experiments provide an innovative look and more details to study the behavior and fate of GONPs.
Mostrar más [+] Menos [-]New flux based dose–response relationships for ozone for European forest tree species Texto completo
2015
Büker, P. | Feng, Z. | Uddling, J. | Briolat, A. | Alonso, R. | Brown, Steve | Elvira, S. | Gerosa, G. | Karlsson, P.E. | Le Thiec, D. | Marzuoli, R. | Mills, G. | Oksanen, E. | Wieser, G. | Wilkinson, M. | Emberson, L.D.
New flux based dose–response relationships for ozone for European forest tree species Texto completo
2015
Büker, P. | Feng, Z. | Uddling, J. | Briolat, A. | Alonso, R. | Brown, Steve | Elvira, S. | Gerosa, G. | Karlsson, P.E. | Le Thiec, D. | Marzuoli, R. | Mills, G. | Oksanen, E. | Wieser, G. | Wilkinson, M. | Emberson, L.D.
To derive O3 dose–response relationships (DRR) for five European forest trees species and broadleaf deciduous and needleleaf tree plant functional types (PFTs), phytotoxic O3 doses (PODy) were related to biomass reductions. PODy was calculated using a stomatal flux model with a range of cut-off thresholds (y) indicative of varying detoxification capacities. Linear regression analysis showed that DRR for PFT and individual tree species differed in their robustness. A simplified parameterisation of the flux model was tested and showed that for most non-Mediterranean tree species, this simplified model led to similarly robust DRR as compared to a species- and climate region-specific parameterisation. Experimentally induced soil water stress was not found to substantially reduce PODy, mainly due to the short duration of soil water stress periods. This study validates the stomatal O3 flux concept and represents a step forward in predicting O3 damage to forests in a spatially and temporally varying climate.
Mostrar más [+] Menos [-]New flux based dose-response relationships for ozone for European forest tree species Texto completo
2015
Büker, P. | Feng, Z. | Uddling, J. | Briolat, A. | Alonso, R. | Braun, S. | Elvira, S. | Gerosa, G | Karlsson, P.E. | Le Thiec, Didier | Marzuoli, R. | Mills, G. | Oksanen, E. | Wieser, G. | Wilkinson, M. | Emberson, L.D. | Environment Department ; Stockholm Environment Institute in York (SEI) | Research Centre for Eco-Environmental Science ; Chinese Academy of Sciences [Changchun Branch] (CAS) | Department of Biological and Environmental Sciences [Gothenburg] ; Göteborgs Universitet = University of Gothenburg (GU) | Ecotoxicology of Air Pollution (CIEMAT) | Institut für Angewandte Pflanzenbiologie (IAP) | Dipartimento di Matematica e Fisica ; Università cattolica del Sacro Cuore [Milano] (Unicatt) | Swedish Environmental Research Institute (IVL) | Ecologie et Ecophysiologie Forestières [devient SILVA en 2018] (EEF) ; Institut National de la Recherche Agronomique (INRA)-Université de Lorraine (UL) | Centre for Ecology and Hydrology ; Bangor University | Department of Biology ; University of Eastern Finland | Department for Natural Hazards and Alpine Timberline ; Federal Research and Training Centre for Forests Natural Hazards and Landscape | Alice Holt Lodge ; Forest Research [Great Britain] | UK Department for Environment, Food and Rural Affairs (Defra - AQ0601) | European Project: 282910
Supplementary data related to this article can be found at :http://dx.doi.org/10.1016/j.envpol.2015.06.033 | To derive O3 dose-response relationships (DRR) for five European forest trees species and broadleaf deciduous and needleleaf tree plant functional types (PFTs), phytotoxic O3 doses (PODy) were related to biomass reductions.[br/]PODy was calculated using a stomatal flux model with a range of cut-off thresholds (y) indicative of varying detoxification capacities. Linear regression analysis showed that DRR for PFT and individual tree species differed in their robustness. A simplified parameterisation of the flux model was tested and showed that for most non-Mediterranean tree species, this simplified model led to similarly robust DRR as compared to a species- and climate region-specific parameterisation.[br/]Experimentally induced soil water stress was not found to substantially reduce PODy, mainly due to the short duration of soil water stress periods.[br/]This study validates the stomatal O3 flux concept and represents a step forward in predicting O3 damage to forests in a spatially and temporally varying climate.
Mostrar más [+] Menos [-]Reproductive endocrine-disrupting effects of triclosan: Population exposure, present evidence and potential mechanisms Texto completo
2015
Wang, Cai-Feng | Tian, Ying
Triclosan has been used as a broad-spectrum antibacterial agent for over 40 years worldwide. Increasing reports indicate frequent detection and broad exposure to triclosan in the natural environment and the human body. Current laboratory studies in various species provide strong evidence for its disrupting effects on the endocrine system, especially reproductive hormones. Multiple modes of action have been suggested, including disrupting hormone metabolism, displacing hormones from hormone receptors and disrupting steroidogenic enzyme activity. Although epidemiological studies on its effects in humans are mostly negative but conflicting, which is typical of much of the early evidence on the toxicity of EDCs, overall, the evidence suggests that triclosan is an EDC. This article reviews human exposure to triclosan, describes the current evidence regarding its reproductive endocrine-disrupting effects, and discusses potential mechanisms to provide insights for further study on its endocrine-disrupting effects in humans.
Mostrar más [+] Menos [-]Development of water quality criteria for phenanthrene and comparison of the sensitivity between native and non-native species Texto completo
2015
Wu, Jiang-Yue | Yan, Zhen-Guang | Liu, Zheng-Tao | Liu, Ji-dong | Liang, Feng | Wang, Xiao-Nan | Wang, Weili
Phenanthrene (PHE) is a priority polycyclic aromatic hydrocarbon (PAH) which is toxic to aquatic organisms. However, there has been no paper dealing with water quality criteria (WQC) of PHE due to the shortage of toxicity data of different taxonomic levels. In the present study, toxicity data were obtained from 8 acute toxicity tests and 3 chronic toxicity tests using 8 Chinese native aquatic species from different taxonomic levels, and the water quality criteria was derived using 3 methods. Furthermore, differences of species sensitivity distributions (SSDs) between native and non-native species were compared. A criterion maximum concentration of 0.0514 mg/L and a criterion continuous concentration of 0.0186 mg/L were developed according to the US EPA guidelines. Finally, by using risk quotient (RQ) to assess the site-specific ecological risk in Liao River, the results indicated that the PHE might pose no risk to local aquatic species.
Mostrar más [+] Menos [-]Humidity plays an important role in the PM2.5 pollution in Beijing Texto completo
2015
Cheng, Yuan | He, Ke-bin | Du, Zhen-yu | Zheng, Mei | Duan, Feng-kui | Ma, Yong-Liang
Heavily-polluted PM2.5 (fine particulate matter) episodes frequently impacting Beijing, especially during winter, have become a substantial concern. We found that during winter, the daily variation of PM2.5 in Beijing tracked the pattern of relative humidity (RH). With the increase of PM2.5 (or RH), water-soluble components (especially inorganic ions) became more abundant, and the water-soluble organic carbon to organic carbon ratios increased. The nitrate to sulfate ratios also exhibited dependence on RH, and were higher than those measured about a decade ago, consistent with the increasing trend of nitrogen oxides emissions. Surprisingly, the ratios of water-insoluble organic carbon to elemental carbon showed significant increase at high RH levels, presumably indicating the formation of secondary organic aerosol that is not soluble in water. In addition, humid winters were occasionally identified during 1996–2013 which are expected to be favorable for the formation of air pollution episodes with high PM2.5 concentrations.
Mostrar más [+] Menos [-]Retrospective study of methylmercury and other metal(loid)s in Madagascar unpolished rice (Oryza sativa L.) Texto completo
2015
Rothenberg, Sarah E. | Mgutshini, Nomathamsanqa L. | Bizimis, Michael | Johnson-Beebout, Sarah E. | Ramanantsoanirina, Alain
Retrospective study of methylmercury and other metal(loid)s in Madagascar unpolished rice (Oryza sativa L.) Texto completo
2015
Rothenberg, Sarah E. | Mgutshini, Nomathamsanqa L. | Bizimis, Michael | Johnson-Beebout, Sarah E. | Ramanantsoanirina, Alain
The rice ingestion rate in Madagascar is among the highest globally; however studies concerning metal(loid) concentrations in Madagascar rice are lacking. For Madagascar unpolished rice (n = 51 landraces), levels of toxic elements (e.g., total mercury, methylmercury, arsenic and cadmium) as well as essential micronutrients (e.g., zinc and selenium) were uniformly low, indicating potentially both positive and negative health effects. Aside from manganese (Wilcoxon rank sum, p < 0.01), no significant differences in concentrations for all trace elements were observed between rice with red bran (n = 20) and brown bran (n = 31) (Wilcoxon rank sum, p = 0.06–0.91). Compared to all elements in rice, rubidium (i.e., tracer for phloem transport) was most positively correlated with methylmercury (Pearson's r = 0.33, p < 0.05) and total mercury (r = 0.44, p < 0.05), while strontium (i.e., tracer for xylem transport) was least correlated with total mercury and methylmercury (r < 0.01 for both), suggesting inorganic mercury and methylmercury were possibly more mobile in phloem compared to xylem.
Mostrar más [+] Menos [-]Retrospective study of methylmercury and other metal(loid)s in Madagascar unpolished rice (Oryza sativa L.) Texto completo
2015
Rothenberg, Sarah E. | Mgutshini, Nomathamsanqa L. | Bizimis, Michael | Johnson-Beebout, Sarah E. | Ramanantsoanirina, Alain
Nitrogen and carbon export from urban areas through removal and export of litterfall Texto completo
2015
Templer, Pamela H. | Toll, Jonathan W. | Hutyra, Lucy R. | Raciti, Steve M.
We found that up to 52 ± 17% of residential litterfall carbon (C) and nitrogen (N; 390.6 kg C and 6.5 kg N ha−1 yr−1) is exported through yard waste removed from the City of Boston, which is equivalent to more than half of annual N outputs as gas loss (i.e. denitrification) or leaching. Our results show that removing yard waste results in a substantial decrease in N inputs to urban areas, which may offset excess N inputs from atmospheric deposition, fertilizer application and pet waste. However, export of C and N via yard waste removal may create nutrient limitation for some vegetation due to diminished recycling of nutrients. Removal of leaf litter from residential areas disrupts nutrient cycling and residential yard management practices are an important modification to urban biogeochemical cycling, which could contribute to spatial heterogeneity of ecosystems that are either N limited or saturated within urban ecosystems.
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