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Modeling results of atmospheric dispersion of NO2 in an urban area using METI–LIS and comparison with coincident mobile DOAS measurements
2015
Dragomir, Carmelia Mariana | Constantin, Daniel-Eduard | Voiculescu, Mirela | Georgescu, Lucian Puiu | Merlaud, Alexis | Roozendael, Michel Van
Synergetic use of in–situ measurements, remote sensing observations and model simulations can provide valuable information about atmospheric chemistry and air quality. In this work we present for the first time a qualitative comparison between modeled NO2 concentrations at ground level using dispersion model METI–LIS and tropospheric NO2 columns obtained by mobile DOAS technique. Experimental and modeling results are presented for a Romanian city, Braila (45.26 ° N, 27.95 ° E). In–situ observations of NO2 and meteorological data from four ground stations belonging to the local environmental agency were used to predict the concentration of NO2 at ground level by atmospheric dispersion modeling on two days when mobile DOAS measurements were available. The mobile DOAS observations were carried out using a UV–VIS spectrometer mounted on board a car. The tropospheric Vertical Column Density (VCD) of NO2 is deduced from DOAS observations. The VCD was obtained using complementary ground and space observations. The correlation between model and DOAS observations is described by a correlation coefficient of 0.33. Also, model results based on averaged in–situ measurements for a period of 5 years (2008–2012) are used for an overview of the background NO2 evolution in time and space for the selected urban area.
显示更多 [+] 显示较少 [-]137Cs, 40K and 210Po in marine mammals from the southern Baltic Sea
2015
Ciesielski, Tomasz | Góral, Marta | Szefer, Piotr | Jenssen, Bjørn Munro | Bojanowski, Ryszard
This study provides information on baseline concentrations of the radionuclides Cesium-137, Potassium-40 and Polonium-210 in sea mammals from the Baltic Sea. The radionuclides were analyzed in the liver, kidney and muscle of harbor porpoises, striped dolphins, and gray and ringed seals from the Polish coast by γ- and α-spectrometry. Median 137Cs activities were 14.8, 13.2 and 23.2Bqkg−1 w.w. in the liver, kidney and muscles, respectively. Activities of 40K and 210Po in the respective tissues were found to be 79.1, 79.8 and 111Bqkg−1 for 40K and 58.1, 59.2 and 32.9Bqkg−1 for 210Po. The measured 137Cs concentrations were extraordinarily high in comparison to those reported in sea mammals from other locations. However, dose assessments did not imply health effects from 137Cs exposure in Baltic Sea mammals. Correlations between 137Cs tissue activities and reported sea water concentrations highlight the potential use of marine mammals for biomonitoring purposes.
显示更多 [+] 显示较少 [-]Recommendations on standardizing lists of marine alien species: Lessons from the Mediterranean Sea
2015
Marchini, Agnese | Galil, Bella S. | Occhipinti, Anna
Analyses of marine alien species based on national/regional datasets are of paramount importance for the success of regulation on the prevention and management of invasive alien species. Yet in the extant data systems the criteria for the inclusion of records are seldom explicit, and frequently inconsistent in their definitions, spatial and temporal frames and comprehensiveness. Agreed-upon uniform guiding principles, based on solid and transparent scientific criteria, are therefore required in order to provide policy makers with validated and comparable data. Following a meta-analysis on the records of marine alien species in the Mediterranean Sea, we recommend a judicious approach to compiling the data. Here, three categories of uncertainty were identified: species' taxonomic identification, species' actual occurrence in the area, and its status as an alien. In proposing guiding principles to standardize such datasets, we aim to encourage discourse on logical, standardized and transparent criteria to substantiate records of alien species.
显示更多 [+] 显示较少 [-]Black coral as a new environmental recorder: The lead profiles in coral skeletons over the past century
2015
Lu, Shan | Cai, Weiying | Zhang, Xiaodi | Li, Xiubao | Huang, Hui | Zhang, Fenfen | Zhang, Jing
Lead (Pb) is a typical heavy metal pollutant in the environment, and most Pb contamination comes from human activities. In the present work, the Pb contents of two black coral specimens (Cirrhipathes spp.) collected from the northern South China Sea were measured by synchrotron radiation micro X-ray fluorescence (SR μ-XRF) analysis with 2.5μm resolution. The results showed that sample SY-1 from the Sanya Bay (near the continent) exhibited higher Pb levels and greater fluctuations than sample XS-1 from the Xisha Islands (off the continent), reflecting the influence of terrestrial input and atmospheric deposition in coastal surface seawater. The present work also demonstrated that the Pb profile in black coral nearshore was highly influenced by human activities, mainly by war and economic development. Thus, black coral may serve as a new potential environmental Pb recorder with SR μ-XRF analytical technology.
显示更多 [+] 显示较少 [-]JNCC guidelines for minimising the risk of injury and disturbance to marine mammals from seismic surveys: We can do better
2015
Wright, Andrew J. | Cosentino, A Mel
The U.K.’s Joint Nature Conservation Committee 1998 guidelines for minimising acoustic impacts from seismic surveys on marine mammals were the first of their kind. Covering both planning and operations, they included various measures for reducing the potential for damaging hearing – an appropriate focus at the time. Since introduction, the guidelines have been criticised for, among other things: the arbitrarily-sized safety zones; the lack of shut-down provisions; the use of mitigation measures that introduce more noise into the environment (e.g., soft-starts); inadequate observer training; and the lack of standardised data collection protocols. Despite the concerns, the guidelines have remained largely unchanged. Moreover, increasing scientific recognition of the scope and magnitude of non-injurious impacts of sound on marine life has become much more widespread since the last revisions in 2010. Accordingly, here we present feasible and realistic recommendations for such improvements, in light of the current state of knowledge.
显示更多 [+] 显示较少 [-]Latitudinal variation and residence time of 137Cs in Indian coastal environment
2015
Sartandel, S.J. | Jha, S.K. | Tripathi, R.M.
Anthropogenic 137Cs activity concentration, in surface sea water along the western and eastern coast of India has been estimated using the in-situ pre-concentration approach. Activity levels of 137Cs ranges from 0.09–1.30Bqm−3 with an overall mean of 0.69±0.29Bqm−3. Latitudinal variation and higher depletion in activity concentration of 137Cs at few locations were observed. Temporal change of 137Cs in sea water along Indian coast unveils a lower effective half-life of 13.8±0.7y in comparison to Asia Pacific regional sea water. The results prevailed that the spatial distribution confers no fresh input of 137Cs in Indian coastal region.
显示更多 [+] 显示较少 [-]Endangered New Caledonian endemic mushroom coral Cantharellus noumeae in turbid, metal-rich, natural and artificial environments
2015
Gilbert, Antoine | Heintz, Tom | Hoeksema, Bert W. | Benzoni, Francesca | Fernandez, Jean-Michel | Fauvelot, Cécile | Andréfouët, Serge
Since its description in 1984, little attention has been paid to the New Caledonian endemic mushroom coral Cantharellus noumeae (Fungiidae), an IUCN Red-listed, endangered coral species. Our study presents the first ever quantitative assessment conducted on C. noumeae populations for two contrasting sites in the same turbid bay. Sites differed by their substrates of artificial or natural origins. Metal concentrations of superficial sediment were measured. C. noumeae was found in high densities in metal-rich and turbid environments at both locations, reaching up to 288 individuals per 50m2. It was 3.5 times more abundant on natural rock than on artificial substrates. Recruitment was also higher proportionally on rock (47% vs 7–14%). The composition of the associated coral communities included 30–37 species occurring in low densities. Our findings clarify the environmental niche of this species and its colonization potential, in order to eventually better characterize its conservation status.
显示更多 [+] 显示较少 [-]How Does Contamination of Rice Soils with Cd and Zn Cause High Incidence of Human Cd Disease in Subsistence Rice Farmers
2015
Chaney, Rufus L.
Rice (Oryza sativa L.) grown on Zn mine waste contaminated soils has caused unequivocal Cd effects on kidney and occasional bone disease (itai-itai) in subsistence rice farmers, but high intake of Cd from other foods has not caused similar effects. Research has clarified two important topics about how Cd from mine waste contaminated rice soils has caused Cd disease: (1) bioaccumulation of soil Cd into rice grain without corresponding increase in Zn, and (2) subsistence rice diets potentiate Cd absorption/bioavailability and risk to farm families. Absorption of Cd by rice roots occurs on the NRAMP5 Mn²⁺ transporter. Although other transporters can influence Cd uptake-transport to shoots and grain, making NRAMP5 null greatly reduces grain Cd. Zn²⁺ has little ability to inhibit Cd²⁺ transfer in rice but clearly inhibits Cd uptake in other plant species. The bioavailability of dietary Cd is increased for subsistence rice diets. Research has identified that low levels and bioavailability of Zn and Fe in polished rice grain cause upregulation of Cd absorption on the Fe²⁺ transporter of duodenum cells (DMT1). Added dietary Zn can also inhibit intestinal Cd absorption somewhat. Nutritional stress (Fe, Zn deficiency) in humans consuming subsistence rice diets thus promotes Cd accumulation and adverse effects. No other dietary (crop) Cd exposure has caused unequivocal Cd-induced renal proximal tubular dysfunction (the first adverse Cd effect) in humans. Recognition of the very unusual nature of Cd risk from rice compared to other crops should be taken into account in setting international limits of Cd in rice and other foods.
显示更多 [+] 显示较少 [-]Bioremediation strategies of hydrocarbons and microbial diversity in the Trindade Island shoreline — Brazil
2015
Rodrigues, Edmo M. | Kalks, Karlos H.M. | Fernandes, Péricles L. | Tótola, Marcos R.
This study analyzed the microbial diversity colonizing the surface of an oil sample during its contact with water, off the Trindade Island coast and simulated the efficiency of eight different bioremediation strategies for this environment. The diversity analysis was performed using acrylic coupons that served as the support for an oil inclusion at sea. The coupons were sampled over 30days, and T-RFLP multiplex was employed to access the diversity of fungi, Bacteria and Archaea present on the oil surface. The bioremediation strategies were simulated in a respirometer. The results showed that the bacterial domain was the most dominant in oil colonization and that the richness of the species attached to the oil gradually increases with the exposure time of the coupons. The combination of biostimulation and bioaugmentation with a native population was proven to be an effective strategy for the remediation of oil off the Trindade Island shoreline.
显示更多 [+] 显示较少 [-]Estimation of the isoprene emission from the Inner Mongolia grassland
2015
Bai, Jianhui
Measurements of isoprene emissions, solar spectral radiation, temperature and relative humidity were carried out at a grassland site in the Inner Mongolia, China during the growing seasons in 2002 and 2003. Isoprene emissions are dependent on PAR (Photosynthetically Active Radiation) and temperature nonlinearly. PAR controls the main processes related to isoprene emission, thus, PAR energy balance is used to establish quantitative relationship between isoprene emission and its affecting factors. An empirical Equation of isoprene emission was built on the basis of PAR energy balance. The calculated values were in good agreement with those measured for 2002 and 2003 summer seasons, the relative biases of 70% estimated emissions were within 50% compared to measured fluxes. The chamber changes the inside environment and emission fluxes, the emission differences were estimated by using the empirical Equation. The results show that isoprene emission flux around the noon decreases by 37% when the chamber is used, i.e., the biggest effect was resulted from PAR difference caused by the chamber. Isoprene emission measured by chamber should be corrected. The empirical model of isoprene emission showed that isoprene emission fluxes were close to zero, when PAR was low in early morning and in late evening. Total isoprene emissions emitted from the grassland in the Inner Mongolia were 1.10 and 1.00gC m−2 during the growing seasons of 2002 and 2003, respectively, which contributed to about 3.1–4.3% and 2.8−3.9% to grass respiration. The averaged isoprene emission normalized to a standard light (1 500μmolm−2 s−1) and temperature (30 °C) condition was 482.8μg m−2 h−1.
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