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Ozone uptake by adult urban trees based on sap flow measurement 全文
2012
Wang, Hua | Zhou, Weiqi | Wang, Xiaoke | Gao, Fuyuan | Zheng, Hua | Tong, Lei | Ouyang, Z. (Zhiyun)
The O₃ uptake in 17 adult trees of six urban species was evaluated by the sap flow-based approach under free atmospheric conditions. The results showed very large species differences in ground area scaled whole-tree ozone uptake ( [Formula: see text] ), with estimates ranging from 0.61 ± 0.07 nmol m⁻² s⁻¹ in Robinia pseudoacacia to 4.80 ± 1.04 nmol m⁻² s⁻¹ in Magnolia liliiflora. However, average [Formula: see text] by deciduous foliages was not significantly higher than that by evergreen ones (3.13 vs 2.21 nmol m⁻² s⁻¹, p = 0.160). Species of high canopy conductance for O₃ ( [Formula: see text] ) took up more O₃ than those of low [Formula: see text] , but that their sensitivity to vapour pressure deficit (D) were also higher, and their [Formula: see text] decreased faster with increasing D, regardless of species. The responses of [Formula: see text] to D and total radiation led to the relative high flux of O₃ uptake, indicating high ozone risk for urban tree species.
显示更多 [+] 显示较少 [-]Does consumption of leafy vegetables grown in peri-urban agriculture pose a risk to human health? 全文
2012
Nabulo, G. | Black, C.R. | Craigon, J. | Young, S.D.
Concentrations of potentially toxic elements were measured in soils and five contrasting tropical leafy vegetables grown in a replicated field trial at five contaminated urban agriculture sites in Kampala City, Uganda. Soil contamination at each site could be tentatively ascribed to known waste disposal practices. There was considerable variation in metal uptake between vegetable types. Washing leafy vegetables reduced chromium and lead concentrations but exogenous contamination of leaves also depended on vegetable type, with Gynandropsis gynandra L. showing a marked tendency to accumulate Pb and Cr. For the worst case scenario of children consuming unwashed vegetables, some metal ‘hazard quotient’ (HQ) limits (1.0) were violated at four of the five sites studied. For the 25 ‘site-vegetable’ combinations assessed, the HQ for Pb exceeded 1.0 in 36% of cases. A vegetable-specific site screening tool based on soil extraction with 0.01M CaCl₂ and extrapolation to provide HQ values was assessed.
显示更多 [+] 显示较少 [-]Natural and anthropogenically-produced brominated compounds in endemic dolphins from Western South Atlantic: Another risk to a vulnerable species 全文
2012
Alonso, Mariana B. | Eljarrat, Ethel | Gorga, Marina | Secchi, Eduardo R. | Bassoi, Manuela | Barbosa, Lupércio | Bertozzi, Carolina P. | Marigo, Juliana | Cremer, Marta | Domit, Camila | Azevedo, Alexandre F. | Dorneles, Paulo R. | Torres, João Paulo M. | Lailson-Brito, José | Malm, Olaf | Barceló, Damià
Liver samples from 53 Franciscana dolphins along the Brazilian coast were analyzed for organobrominated compounds. Target substances included the following anthropogenic pollutants: polybrominated diphenyl ethers (PBDEs), polybrominated biphenyls (PBBs), pentabromoethylbenzene (PBEB), hexabromobenzene (HBB), decabromodiphenylethane (DBDPE), as well as the naturally-generated methoxylated-PBDEs (MeO-PBDEs). PBDE concentrations ranged from 6 to 1797 ng/g lw (mean 166 ± 298 ng/g lw) and were similar to those observed in cetaceans from Northern Hemisphere. PBBs were found in all sampling locations (<LOQ to 57 ng/g lw). DBDPE was detected in 42% of the dolphins from the most industrialized Brazilian state and the concentrations ranging from <LOQ to 352 ng/g lw. Franciscana dolphins from the tropical Brazilian shore presented the highest MeO-PBDE concentrations ever reported for coastal cetaceans (up to 14 μg/g lw). Eight MeO-PBDE congeners were detected and the present investigation constituted the first record of occurrence of six of them in marine mammal livers.
显示更多 [+] 显示较少 [-]Environmental contextualisation of potential toxic elements and polycyclic aromatic hydrocarbons in biochar 全文
2012
Freddo, Alessia | Cai, Chao | Reid, Brian J.
Nine dissimilar biochars, produced from varying feedstock at different pyrolysis temperatures, are appraised with respect to concentrations of potentially toxic elements, specifically, metals, metalloids and polycyclic aromatic hydrocarbons (PAHs). Concentrations of the metals and metalloids varied with the following ranges (mg kg⁻¹): 0.02–0.94, Cd; 0.12–6.48, Cr; 0.04–13.2, Cu; 0.1–1.37, Ni; 0.06–3.87, Pb; 0.94–207, Zn and 0.03–0.27, As. Σ₁₆PAH concentrations (16 Environmental Protection Agency (EPA) PAHs) range between 0.08 mg kg⁻¹ to 8.7 mg kg⁻¹. Subsequent comparison with background soil concentrations, concentration applied to the regulation of composted materials (Publicly Available Specification (PAS 100)) and European Union (EU) regulations relating to the application of sewage sludge to agricultural land suggest low risk associated with the concentrations of PTEs observed in biochar. Collectively, results suggest that environmental impacts attributable to metals, metalloids and PAHs associated with biochar following its application to soil are likely to be minimal.
显示更多 [+] 显示较少 [-]Effects of ethinylestradiol and of an environmentally relevant mixture of xenoestrogens on steroidogenic gene expression and specific transcription factors in zebrafish 全文
2012
Urbatzka, R. | Rocha, E. | Reis, B. | Cruzeiro, C. | Monteiro, R.A.F. | Rocha, M.J.
In natural environments fish are exposed to endocrine disrupting compounds (EDCs) present at low concentrations and with different modes of actions. Here, adult zebrafish of both sexes were exposed for 21 days to an estrogenic mixture (Mix) of eleven EDCs previously quantified in Douro River estuary (Portugal) and to 100 ng/L 17α-ethinylestradiol (EE2) as positive control. Vitellogenin mRNA and HSI in males confirmed both exposure regimes as physiologically active. Potential candidates for estrogenic disturbance of steroidogenesis were identified (StAR, 17β-HSD1, cyp19a1), but Mix only affected cyp19a1 in females. Significant differences in the response of FSHβ, cypa19a2, 20β-HSD were observed between EE2 and Mix. Mtf-1 and tfap2c transcription factor binding sites were discovered in the putative promoter regions and corresponding transcription factors were found to be differentially expressed in response to Mix and EE2. The results suggest that “non-classical effects” of estrogenic EDC in fish are mediated via transcription factors.
显示更多 [+] 显示较少 [-]Induction of mouthpart deformities in chironomid larvae exposed to contaminated sediments 全文
2012
Di Veroli, Alessandra | Goretti, Enzo | Paumen, Miriam Leόn | Kraak, Michiel H.S. | Admiraal, Wim
The aim of the present study was to improve the cause–effect relationship between toxicant exposure and chironomid mouthpart deformities, by linking induction of mouthpart deformities to contaminated field sediments, metal mixtures and a mutagenic polycyclic aromatic compound metabolite (acridone). Mouthpart deformities in Chironomus riparius larvae were induced by both the heavy metal mixture and by acridone. A clear correlation between metal concentrations in the sediment and deformities incidence was only observed when the contaminated field sediments were left out of the analysis, probably because these natural sediments contained other toxic compounds, which could be responsible for a higher incidence of deformities than predicted by the measured metal concentrations only. The present study clearly improved the cause–effect relationship between toxicant exposure and the induction of mouthpart deformities. It is concluded that the incidence of mouthpart deformities may better reflect the potential toxicity of contaminated sediments than chemical analysis.
显示更多 [+] 显示较少 [-]Summer atmospheric polybrominated diphenyl ethers in urban and rural areas of northern China 全文
2012
Wang, Chen | Li, Wei | Chen, Jiwei | Wang, Hongqijie | Li, Tongchao | Shen, Guofeng | Shen, Huizhong | Huang, Ye | Wang, Rong | Wang, Bin | Zhang, Yanyan | Tang, Jianhui | Liu, Wenxin | Wang, Xilong | Tao, Shu
High levels of polybrominated diphenyl ethers (PBDEs) have been extensively reported in urban areas and at e-waste recycling sites in coastal China. However, data are scarce in northern China and are not available in rural areas at all. In addition, it is often believed that air concentrations in rural areas are lower than those in urban areas without distinguishing rural residential areas and open fields. In this study, air samples were collected at 17 sites covering urban and rural (residential and open field) areas in northern China using active samplers. With BDE-209 dominated in all congeners, the average concentrations of BDE-209 (41 ± 72 pg/m³) and other 13 PBDEs (16 ± 12 pg/m³) were significantly lower than those found in south China, such as in Guangzhou or Hong Kong. On average, the total PBDE concentrations at the urban sites were 2.2 and 2.9 times of those at the rural residential and field sites, respectively.
显示更多 [+] 显示较少 [-]The effect of airborne particles and weather conditions on pediatric respiratory infections in Cordoba, Argentine 全文
2012
The effect of airborne particles and weather conditions on pediatric respiratory infections in Cordoba, Argentine 全文
2012
We studied the effect of estimated PM₁₀ on respiratory infections in children from Cordoba, Argentine as well as the influence of weather factors, socio-economic conditions and education. We analyzed upper and lower respiratory infections and applied a time-series analysis with a quasi-Poisson distribution link function. To control for seasonally varying factors we fitted cubic smoothing splines of date. We also examined community-specific parameters and differences in susceptibility by sex. We found a significant association between particles and respiratory infections. This relationship was affected by mean temperature, atmospheric pressure and wind speed. These effects were stronger in fall, winter and spring for upper respiratory infections while for lower respiratory infections the association was significant only during spring. Low socio-economic conditions and low education levels increased the risk of respiratory infections. These findings add useful information to understand the influence of airborne particles on children health in developing countries.
显示更多 [+] 显示较少 [-]The effect of airborne particles and weather conditions on pediatric respiratory infections in Cordoba, Argentine 全文
2012
Amarillo, Ana Carolina | Carreras, Hebe Alejandra
We studied the effect of estimated PM10 on respiratory infections in children from Cordoba, Argentine as well as the influence of weather factors, socio-economic conditions and education. We analyzed upper and lower respiratory infections and applied a time-series analysis with a quasi-Poisson distribution link function. To control for seasonally varying factors we fitted cubic smoothing splines of date. We also examined community-specific parameters and differences in susceptibility by sex. We found a significant association between particles and respiratory infections. This relationship was affected by mean temperature, atmospheric pressure and wind speed. These effects were stronger in fall, winter and spring for upper respiratory infections while for lower respiratory infections the association was significant only during spring. Low socio-economic conditions and low education levels increased the risk of respiratory infections. These findings add useful information to understand the influence of airborne particles on children health in developing countries. | Fil: Amarillo, Ana Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina. Universidad Nacional de Cordoba. Facultad de Ciencias Exactas Fisicas y Naturales. Departamento de Quimica; Argentina | Fil: Carreras, Hebe Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina. Universidad Nacional de Cordoba. Facultad de Ciencias Exactas Fisicas y Naturales. Departamento de Quimica; Argentina
显示更多 [+] 显示较少 [-]Diversities of phthalate esters in suburban agricultural soils and wasteland soil appeared with urbanization in China 全文
2012
Kong, Shaofei | Ji, Yaqin | Liu, Lingling | Chen, Li | Zhao, Xueyan | Wang, Jiajun | Bai, Zhipeng | Sun, Zengrong
The distribution of six priority phthalic acid esters (PAEs) in suburban farmland, vegetable, orchard and wasteland soils of Tianjin were obtained with gas chromatography-mass spectrometer analysis in 2009. Results showed that total PAEs varied from 0.05 to 10.4 μg g⁻¹, with the median value as 0.32 μg g⁻¹. Di-(2-ethylhexyl) phthalate and di-n-butyl phthalate are most abundant species. PAEs concentrations for the four types of soils exhibited decreasing order as vegetable soil > wasteland soil > farmland soil > orchard soil. PAEs exhibited elevated levels in more developed regions when compared with other studies. The agricultural plastic film could elevate the PAEs contents in soils. Principal component analysis indicated the emission from cosmetics and personal care products and plasticizers were important sources for PAEs in suburban soils in Tianjin. The higher PAEs contents in wasteland soils from suburban area should be paid more attention owing to large amounts of solid wastes appeared with the ongoing urbanization.
显示更多 [+] 显示较少 [-]Assessment of N and P status at the landscape scale using environmental models and measurements 全文
2012
We assessed the compliance of a Dutch landscape, dominated by dairy farming, with environmental quality standards using a combination of model calculations and measurements. The total ammonia emission of 2.4 kton NH₃ yr⁻¹ does not exceed the environmental quality standard (2.6 kton NH₃ yr⁻¹). Nevertheless, the total N deposition (on average 24.4 kg N ha⁻¹ yr⁻¹) is such that critical N loads are exceeded at 53% of the nature areas. The deposited N mainly results from non-agricultural sources and agricultural sources outside the area (72%). The calculated average NO₃ ⁻ concentration in the upper groundwater does not exceed the 50 mg l⁻¹ threshold. Calculated annual average N-total and P-total concentrations in discharge water are relatively high but these cannot be directly compared with thresholds for surface water. The results suggest that compliance monitoring at the landscape scale needs to include source indicators and cannot be based on state indicators alone.
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