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91.
Licata P  Bella GD  Dugo G  Naccari F 《Chemosphere》2003,52(1):231-238
The aim of this research was to investigate the presence of organochlorine pesticides, PCBs and heavy metals (Cd, Cr, Cu, Ni, Pb and Zn) in fish living in lake Ganzirri and the Straits of Messina, using the mullet Liza aurata as a "biological indicator". Different tissues of Liza aurata, which include the muscle, gill and vertebral column, were taken for analyses. Quantitative determination of the organochlorine compounds was performed by GC-ECD and confirmed with GC-MS. The concentrations of "essential" and "toxic" heavy metals were determined by Atomic Absorption Spectrophotometry. For the mullets of lake Ganzirri, the study showed DDE in three samples of gills and one of muscle, at concentrations below the MRL; no appreciable residues of PCBs (Aroclor 1232 series) were found. The concentrations of Zn and Cu were much higher than those of the "toxic" metals. No traces of organochlorine pesticides and PCBs were found in the individuals from the Straits of Messina. Therefore, these results indicate that these two environments are not at toxicological risk.  相似文献   
92.
Platinum and Rh content in the atmosphere of Rome as released by car catalytic converters was monitored from 1998 to 2000 in six urban sites with different traffic intensities and in one rural area. Samples collected with medium-volume PM10 samplers were analyzed by Sector Field Inductively Coupled Plasma Mass Spectrometry (SF-ICP-MS). The Pt content varied from 2.4 to 60.1 pg m(-3) (mean value 17.8 pg m(-3)) at the urban locations whilst that of Rh spanned the range 0.8-9.4 pg m(-3) (average value 4.0 pg m(-3)). The rural area showed metal levels mostly below the limits of detection, pointing to automobile traffic as the main source of those elements in the urban atmosphere. The highest mean concentrations of Pt and Rh, ie. 22.2 and 5.0 pg m(-3), were detected along the ring road where the traffic density is high (>100,000 vehicles per day) and the driving speed between 100 and 120 km h(-1). The lowest Pt and Rh mean concentrations, i.e. 11.4 and 3.4 pg m(-3), were measured downtown, where traffic density is lower (20,000 vehicles per day) and the driving speed is limited (50 km h(-1)). Significant concentrations of Pt and Rh were found in the vicinity of traffic signals, indicating that the "stop-and-go" conditions might also affect their release. The measured Pt/Rh ratio spanned the range 3.3-5.9 in accordance with that present in the more commonly used gasoline car catalytic converters. Seasonal variations between wintertime (with Pt and Rh mean concentrations of 23.8 and 5.1 pg m(-3), respectively) and summertime (with Pt and Rh mean concentrations of 14.1 and 3.3 pg m(-3), respectively) were also observed.  相似文献   
93.
A natural deactivation of chrysotile asbestos occurs on serpentinite rocks where lichens selectively grow on the fibres and secrete metabolites, including oxalic acid, which, in the long term, turn the fibres into a non-toxic amorphous material.  相似文献   
94.
Organochlorine Pesticides and PCBs in Wild Boars from Calabria (Italy)   总被引:1,自引:0,他引:1  
At present, there are no specific studies on the evaluation of environmental toxicological risks in Calabria (south of Italy) and on the presence of contaminants in the fauna of this region. The aim of the present research was to investigate the levels of contamination by OC pesticides and PCBs in some organs and tissues of wild boars (utilized as 'biological indicator') from various areas of Calabria. Quantitative determinations of organochlorines were carried out using GC-ECD and confirmed with GC-MS in 154 samples from wild boars (heart, liver, lung, kidney, muscle tissue and spleen) during the hunting season from 2000 to 2002. The results indicate the low residual levels of DDE in 8 samples and DDT in 4 samples and PCBs residues (Aroclor 1232) below the detection limits were found. Therefore, these results show that the Calabria region is not at contamination risk from organochlorines and moreover is free from health problems for the consumer of boar meat.  相似文献   
95.
Over the past decades, information and communication technologies (ICT) established themselves as the key force towards more effective and efficient usage of resources in our society, namely via better use of available information, automation, stakeholder involvement, and decision support. By analyzing recent advancements in knowledge offered by ICT, it is possible to identify their strong correlation with the principles, aims, and interests of sustainability science, which can be highly inspired by ICT-intensive domains. In this paper, we study the theoretical background on system thinking as an interpretative lens able to support better understanding of dimensions and dynamics involved in the domain of sustainability, and examine the role of ICT in advancing sustainability goals. Then, we analyze the domain of the Smart Grid as a prominent example of complex technological contribution in face of the challenges of sustainability, and present the insights from this domain, which are turned into sustainability guidelines for other domains, linking smartness, and sustainability in the light of systems thinking and Smart Grid experience. In summary, the core recommendation of this work is the employment of information technology to widen the scope of the sustainability “game” by sliding activities in time and space, and in engaging more “players” in the game, which is now made possible thanks to the advancement in ICT.  相似文献   
96.
A new analytical method was developed for the determination of formaldehyde in ambient air based on the use of a modified configuration of the Analyst® passive sampler. It consists of a polyethylene cylinder filled with appropriate reactive adsorbent and a special anti-turbulence net which works as an ozone scrubber.The performance of a diffusive sampler depends critically on the selection and use of a suitable adsorbent and on environmental factors, such as temperature, humidity and the interference of oxidant species. In this study two adsorbent types were investigated: 2,4-dinitrophenylhydrazine (2,4-DNPH) coated silica gel and Florisil® particles. Interference of ozone was removed by using a silver net upstream as an anti-turbulence device. The performance of this net was then compared with that of stainless steel. Furthermore, the aim of the work was the optimization of the adsorbent type and the study of the interference of ozone with particular attention placed on the effect of relative humidity and temperature.A dynamic system for generating a known concentration of the test gas (formaldehyde) in an appropriate exposure chamber was used to evaluate the performance of the passive sampler and to allow the calibration of the methodology. Inter-comparisons with a reference method, active sampling using 2,4-DNPH-silica gel coated cartridges, were also carried out. Results were in accordance with each other.Tests were planned using a statistical method based on Design of Experiment methodology. The operating conditions were chosen in order to obtain the best configuration of the passive device by evaluating the statistical significance of the different factors and their interactions by analysis of variance.Results showed that the best configuration was achieved using 2,4-DNPH Florisil® coated particles as an adsorbent and a silver anti-turbulence net as an ozone scrubber.With the aim of achieving further results in realistic conditions, some field experiments were also carried out.  相似文献   
97.
The process of reducing acid leaching of manganiferous ore is aimed at the extraction of manganese from low grade manganese ores. This work is focused on the iron removal operation. The following items have been considered in order to investigate the effect of the main operating conditions on solid waste disposal and on the process costs: (i) type and quantity of the base agent used for iron precipitation, (ii) effective need of leaching waste separation prior to the iron removal operation, (iii) presence of a second leaching stage with the roasted ore, which might also act as a preliminary iron removal step, and (iv) effect of tailings washing on the solid waste classification. Different base compounds have been tested, including CaO, CaCO3, NaOH, and Na2CO3. The latter gave the best results concerning both the precipitation process kinetics and the reagent consumption. The filtration of the liquor leach prior to iron removal was not necessary, implying significant savings in capital costs. A reduction of chemical consumption and an increase of manganese concentration in the solution were obtained by introducing secondary leaching tests with the previously roasted ore; this additional step was introduced without a significant decrease of global manganese extraction yield. Finally, toxicity characteristic leaching procedure (TCLP) tests carried out on the leaching solid waste showed: (i) a reduction of arsenic mobility in the presence of iron precipitates, and (ii) the need for a washing step in order to produce a waste that is classifiable as not dangerous, taking into consideration the existing Environmental National Laws.  相似文献   
98.
The Sarno River is nicknamed “the most polluted river in Europe”. The main goal of this study is to enhance our knowledge on the Sarno River water and sediment quality and on its environmental impact on the gulf of Naples (Tyrrhenian Sea, Central Mediterranean Sea) in order to become a useful assessment tool for the regional administrations. For these reasons, 32 selected polychlorinated biphenyls (PCBs) and aldrin, α-BHC, β-BHC, δ-BHC, γ-BHC (lindane), 4,4′-DDD, 4,4′-DDE, 4,4′-DDT, dieldrin, endosulfan I, endosulfan II, endosulfan sulphate, endrin, endrin aldehyde, heptachlor, heptachlor epoxide (isomer B) and methoxychlor were determined in the water dissolved phase (DP), suspended particulate matter (SPM) and sediments. Total concentrations of PCBs ranged from 1.4 to 24.9 ng L?1 in water (sum of DP and SPM) and from 1.01 to 42.54 ng g?1 in sediment samples. The concentrations of total organochlorine pesticides (OCPs) obtained in water (sum of DP and SPM) ranged from 0.54 to 7.32 ng L?1 and from 0.08 to 5.99 ng g?1 in sediment samples. Contaminant discharges of PCBs and OCPs into the sea were calculated in about 1,247 g day?1 (948 g day?1 of PCBs and 326 g day?1 of OCPs), showing that this river should account as one of the main contribution sources of PCBs and OCPs to the Tyrrhenian Sea.  相似文献   
99.
The emission, transport, deposition and eventual fate of mercury (Hg) in the Mediterranean area has been studied using a modified version of the Weather Research and Forecasting model coupled with Chemistry (WRF/Chem). This model version has been developed specifically with the aim to simulate the atmospheric processes determining atmospheric Hg emissions, concentrations and deposition online at high spatial resolution. For this purpose, the gas phase chemistry of Hg and a parametrised representation of atmospheric Hg aqueous chemistry have been added to the regional acid deposition model version 2 chemical mechanism in WRF/Chem. Anthropogenic mercury emissions from the Arctic Monitoring and Assessment Programme included in the emissions preprocessor, mercury evasion from the sea surface and Hg released from biomass burning have also been included. Dry and wet deposition processes for Hg have been implemented. The model has been tested for the whole of 2009 using measurements of total gaseous mercury from the European Monitoring and Evaluation Programme monitoring network. Speciated measurement data of atmospheric elemental Hg, gaseous oxidised Hg and Hg associated with particulate matter, from a Mediterranean oceanographic campaign (June 2009), has permitted the model’s ability to simulate the atmospheric redox chemistry of Hg to be assessed. The model results highlight the importance of both the boundary conditions employed and the accuracy of the mercury speciation in the emission database. The model has permitted the reevaluation of the deposition to, and the emission from, the Mediterranean Sea. In light of the well-known high concentrations of methylmercury in a number of Mediterranean fish species, this information is important in establishing the mass balance of Hg for the Mediterranean Sea. The model results support the idea that the Mediterranean Sea is a net source of Hg to the atmosphere and suggest that the net flux is ≈30 Mg year?1 of elemental Hg.  相似文献   
100.
ObjectiveThis cross-sectional study was conducted to assess the relationship between exposure to cadmium and circulating reproductive hormone levels in urban and rural male workers.Materials and MethodsUrinary cadmium, blood cadmium, luteinizing hormone (LH), follicle stimulating hormone (FSH) and testosterone were obtained from 86 non-smoking traffic policemen and 86 subjects working as roadmen in a rural area. All subjects were monitored to evaluate airborne exposure to cadmium.ResultsThe mean value of exposure to cadmium was 1.3 ng m?3 in traffic policemen, while the mean value was less than 0.5 ng m?3 in roadmen. The mean concentrations of urinary cadmium (1.4 vs. 0.9 μg g?1 creatinine; p = 0.001), blood cadmium (1.1 vs. 0.7 μg l?1; p = 0.000), FSH (2.6 vs. 3.2 μlU ml?1; p = 0.02) and LH (2.6 vs. 3.1 μlU ml?1; p = 0.03) were significantly different between traffic policemen and roadmen. No differences were found in the mean values of testosterone between the two groups. Multiple linear regression models showed associations between (a) urinary cadmium, airborne cadmium, working life, job category and consumption of water from water supply (b) blood cadmium, airborne cadmium and job category (c) the values of FSH and age, working life, job category, urinary cadmium and blood cadmium (d) the values of LH and both the age and working life.ConclusionThe above results must be confirmed by further studies, but they indicate the influence of exposure to the cadmium present in urban air on the circulating FSH, even at low doses.  相似文献   
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