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41.
Gianfranco Brambilla Stefania Paola De Filippis Vittorio Esposito Gaetano Settimo 《洁净——土壤、空气、水》2013,41(2):113-118
Dioxin‐like compounds from regular, occasional or fugitive airborne sources of emission may fall out on fodders close to be harvested for silage and hay production. In this way, a prolonged long‐term intake of contaminated forages in dairy animals may be envisaged, able to determine a rise of the background contamination in milk. We simulated different risk scenarios taking into account the inventoried bulk dry depositions in rural areas of the aforesaid contaminants, silage and hay biomass production per hectare, forages regimen in dairy animals, and the congeners carry‐over rate (COR) from forages to milk. Considering atmospheric depositions >10 pg I‐TE m?2 day?1 and accounting for a 30% COR, dairy milk could rise up to the PCDD/F level of 3 pg WHO1998‐TE g?1 fat. The modelling indicates that in rural areas bulk emissions should be selectively minimised, accounting for the calendar of the different agricultural practices, because of their potential impact on the fodders. Since environmental factors play a non‐negligible role in food production, a stronger harmonisation between I‐TE and WHO1998–2005‐TE scales with respect to dioxin‐like polychlorobiphenyl congeners inclusion is envisaged. This will allow the prevention of the human indirect exposure to such contaminants when released in the air. 相似文献
42.
Cristiana Guerranti Stefania Ancora Nicola Bianchi Guido Perra Emiliano Leonida Fanello Simonetta Corsolini Maria Cristina Fossi Silvano Ettore Focardi 《Marine pollution bulletin》2013
Perfluorinated compounds (PFCs), widely used for their hydro-oil repellent properties, are almost non-degradable in the environment; there is scientific evidence that indicate bioaccumulation. They represent a threat to many organisms, because they are toxic and are endocrine disruptors. Scientific studies have demonstrated the presence of PFCs in blood and liver samples of fish, turtles, birds and mammals of marine ecosystems in different geographical areas. The aim of this study was to determine the distribution of PFOS and PFOA in blood samples of the marine turtle Caretta caretta, using a minimally invasive sampling procedure. 49 blood samples of marine turtle, taken from several Italian marine turtle rescue centers, were analyzed. While PFOA was never detected, measurable concentrations of PFOS were found in 15 blood samples; the values show a range from 1.14 ng/g to 28.51 ng/g (wet wt.). No differences between groups of samples taken from different areas were found. 相似文献
43.
Stefania Bilardi Richard T. Amos David W. Blowes Paolo S. Calabrò Nicola Moraci 《Ground Water Monitoring & Remediation》2013,33(1):97-104
MIN3P, a multicomponent reactive transport model for variably saturated porous media, is used to simulate the outputs of column tests carried out using zero valent iron (ZVI) for nickel contaminated groundwater remediation. The objective of this study is to investigate the main chemical reactions involved in contaminant removal and the main causes of the reactivity decline of ZVI over time. According to the results of the model the major causes of ZVI reactivity loss is identified in the mineral precipitation of α‐FeOOH on iron surface that probably caused ZVI passivation and led to a decline of the electron transfer rate. An existing empirical relationship between mineral precipitation and the reactivity loss of ZVI, included in the model, reproduced the changes in nickel removal observed during different laboratory column tests. 相似文献
44.
Piazza R Giuliani S Bellucci LG Mugnai C Cu NH Nhon DH Vecchiato M Romano S Frignani M 《Marine pollution bulletin》2010,60(12):2303-2310
Samples from nine Central Vietnam coastal lagoons, together with three soils and sediments collected in two freshwater reservoirs of the Thua Thien-Hué province, were analysed for polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). Total concentrations are low, from 192 to 2912 pg g−1 and depth profiles in Tam Giang-Cau Hai (TG-CH) sediment cores show only minor changes over time in PCDD/F input and composition. Octachloro dibenzo-p-dioxin (OCDD) is the prevailing congener (approximately 90%), indicating combustion as the main PCDD/F source to these coastal systems, whereas natural formation might be partly responsible for the presence at depth. 2,3,7,8-Tetrachloro dibenzo-p-dioxin (TCDD), largely sprayed together with Agent Orange over the study areas during the war (1961–1971), is absent or very low. This result supports the hypothesis of strong degradation soon after spraying. Multivariate statistical analyses account for the presence of local, short-range sources as observed in the northern part of the TG-CH lagoon. 相似文献
45.
Giuseppe Crosa Elena Castelli Gaetano Gentili Paolo Espa 《Aquatic Sciences - Research Across Boundaries》2010,72(1):85-95
The downstream ecological consequences of two controlled “free flow” flushing operations designed to remove sediments accumulated
in an alpine reservoir are described. The main objectives of the study were (a) to verify to what extent the suspended solid
concentration (SSC) in the receiving water course can be controlled by flushing operations, (b) to determine the biological
consequences of flushing operations, and (c) to produce technical guidelines for the future planning and monitoring of these
activities. We found that the flushing of large volumes of accumulated sediment had clear effects on the stream ecosystem
due to the unpredictability of short duration SSC peaks (70–80 g L−1) and the high average SSC (4–5 g L−1) within flushing periods. The main impacts were decreased fish densities (up to 73%) and biomass (up to 66%). A greater mortality
recorded for juveniles will likely result in long-term impairment of the age-structures of future fish populations. The zoobenthic
assemblages, despite exhibiting a drastic reduction in abundance following the first floods, showed substantial recovery within
3 months of the beginning of flushing operations. Regular sediment removal by yearly flushing is recommended in order to avoid
SSC peaks and to facilitate the control of scouring effects caused by the water used to wash out sediments. We also recommend
maximum allowable SSCs of 10 g L−1 (daily average) and 5 g L−1 (overall average) for flushing operations carried out in similar environmental contexts. 相似文献
46.
47.
Serena Cattari Stefania Degli Abbati Daniele Ferretti Sergio Lagomarsino Daria Ottonelli Antonio Tralli 《Bulletin of Earthquake Engineering》2014,12(5):2333-2365
The medieval fortresses are a very common and distinctive type among the Emilian historical constructions and the earthquake of May 20 and 29, 2012 highlighted their high vulnerability. Starting from the analysis of the geometrical and constructive features, the interpretation of their seismic vulnerability has been based on an accurate damage assessment and supported by the numerical results of typical configurations. An abacus of recurring seismic damage mechanisms in fortresses has been proposed: it in particular concerns the towers and their interaction with the fortress perimeter walls. Moreover, the seismic response of the most important fortresses in the epicentral area has been described referring to their historical notes, the recent interventions and their influence on the seismic damage. 相似文献
48.
Igor Petenko Giangiuseppe Mastrantonio Angelo Viola Stefania Argentini Ilaria Pietroni 《Boundary-Layer Meteorology》2012,143(1):125-141
Some characteristics of wavelike motions in the atmospheric boundary layer observed by sodar are considered. In an experiment
carried out in February 1993 in Milan, Italy, Doppler sodar measurements were accompanied by in situ measurements of temperature
and wind velocity vertical profiles using a tethered balloon up to 600 m. The oscillations of elevated wavy layers containing
intense thermal turbulence, usually associated with temperature-inversion zones, were studied by using correlation and spectral
analysis methods. The statistics of the occurrence of wavelike and temperature-inversion events are presented. The height
distributions of Brunt–Vaisala frequency and wind shear and their correlation within elevated inversion layers were determined,
with a strong correlation observed between the drift rate of the wavy layers and the vertical velocity measured by Doppler
sodar inside these layers. Spectral analysis showed similarities regarding their frequency characteristics. The phase speed
and propagation direction of waves were estimated from the time delay of the signals at three antennae to provide estimates
of wavelength. Moreover, wavelengths were estimated from the intrinsic frequency obtained from sodar measurements of the Doppler
vertical velocity and oscillations of wavy turbulent layers. The two wavelength estimates are in good agreement. 相似文献
49.
Stefania Abakerli 《Geoforum》2001,32(4)
More than a strategy for environmental conservation, protected area paradigm has represented a specific conception of nature–society relationship. Originated in a context of capitalist consolidation, rapid urbanisation and frontier development in the US, this paradigm has given rise to a ‘politically viable rationale' in which utilitarian use of natural resources by tourism development would ensure nature preservation. This political rationality has deeply influenced environmental policies in developing countries, fostering a paradoxical model in the history of nature preservation. It also has brought into play diverse interests that have shifted patterns of local nature–society interaction, configuring a complex politicised environment. Established in ‘isolated' regions, protected areas have been implemented often by top–down approaches, disrupting resident peoples' livelihoods strategies through conflicts over the control of natural resources. Understanding the implications of development and conservation policies on resident peoples' livelihoods may represent a starting point for an integrated developmental conservation policy towards the promotion of sustainable livelihoods in environmentally sensitive regions in developing countries. These issues are analysed in the region of the Lençois Maranhenses National Park in Brazil. This paper argues that the context facing the region reveals a standardised conservationist paradigm marked by the absence of wider ecological criteria informing nature protection and a disregard for the strengthening of sustainability in existent socio-economic dynamics. The regional development and conservation policies have not only promoted tensions between resident peoples' livelihoods and the protected area paradigm, but also reinforced the legitimisation of social exclusion and environmental disruption under the prevalent rhetoric of nature protection and tourism development. 相似文献
50.
Alessio Cislaghi Daniele Masseroni Christian Massari Stefania Camici Luca Brocca 《水文科学杂志》2020,65(3):348-370
ABSTRACTSelecting the best structure and parameterization of rainfall–runoff models is not straightforward and depends on a broad number of factors. In this study, the “Modello Idrologico Semi-Distribuito in continuo” (MISDc) was tested on 63 mountainous catchments in the western Po Valley (Italy) and the optimal model parameters were regionalized using different strategies. The model performance was evaluated through several indexes analysing hydrological regime, high-flow condition and flow–duration curve (FDC). In general, MISDc provides a good fit behaviour with a Kling-Gupta Efficiency index greater than 0.5 for 100% and 84% of cases for calibration and validation, respectively. Concerning the regionalization, spatial proximity approach is the most accurate solution obtaining satisfactory performance. Lastly, the predicted FDCs showed an excellent similarity with the observed ones. Results encourage to apply MISDc over the study area for flood forecasting and for assessing water resources availability thanks to the modest computational efforts and data requirements. 相似文献