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211.
Nitrate and nitrite are toxicants that have become increasingly significant environmental chemicals. Increase in environmental distribution of nitrogenous compounds, especially in surface and ground water, has been attributed to the intensive use of nitrate as agricultural fertilizers and to increasing amounts of nitrogenous wastes produced by municipalities, industries, and feedlots. The purpose of this study is to illustrate a fatal nitrate toxicosis in cattle associated with the consumption of fennels (Foeniculum vulgare). Fifteen cows from the same farm suddenly developed weakness, muscular tremors, respiratory distress, and finally convulsions. The affected animals died within 24 to 48 h from the onset of the clinical signs. Five cows underwent a complete post-mortem examination. In all examined animals, gross lesions included presence of dark unclotted blood around the nostrils and the anal region, moderate inflammation of the gastrointestinal mucosa, and brown discoloration of the skeletal muscles and kidneys. The histological examination showed tubular degeneration and congestion of glomerular vessels in the kidney. Toxicological analysis detected nitrates at 4 672.2 ppm in the fennels used to feed the animals. The source of exposure to nitrates was identified in the fennels. The fennels were grown in a polluted area of the Campania region in southern Italy and distributed in a public market for human consumption. The waste from the sale of the fennels was fed to the cows. The accumulation of nitrates in some vegetables poses a risk not only for animal health but also for human and environmental safety.  相似文献   
212.
Composition of exhaust from a ship diesel engine using heavy fuel oil (HFO) was investigated onboard a large cargo vessel. The emitted particulate matter (PM) properties related to environmental and health impacts were investigated along with composition of the gas-phase emissions. Mass, size distribution, chemical composition and microphysical structure of the PM were investigated. The emission factor for PM was 5.3 g (kg fuel)?1. The mass size distribution showed a bimodal shape with two maxima: one in the accumulation mode with mean particle diameter DP around 0.5 μm and one in the coarse mode at DP around 7 μm. The PM composition was dominated by organic carbon (OC), ash and sulphate while the elemental carbon (EC) composed only a few percent of the total PM. Increase of the PM in exhaust upon cooling was associated with increase of OC and sulphate. Laser analysis of the adsorbed phase in the cooled exhaust showed presence of a rich mixture of polycyclic aromatic hydrocarbon (PAH) species with molecular mass 178–300 amu while PM collected in the hot exhaust showed only four PAH masses.Microstructure and elemental analysis of ship combustion residuals indicate three distinct morphological structures with different chemical composition: soot aggregates, significantly metal polluted; char particles, clean or containing minerals; mineral and/or ash particles. Additionally, organic carbon particles of unburned fuel or/and lubricating oil origin were observed. Hazardous constituents from the combustion of heavy fuel oil such as transitional and alkali earth metals (V, Ni, Ca, Fe) were observed in the PM samples.Measurements of gaseous composition in the exhaust of this particular ship showed emission factors that are on the low side of the interval of global emission factors published in literature for NOx, hydrocarbons (HC) and CO.  相似文献   
213.
This paper presents the results of an intensive monitoring activity of the particulate, fall-out and soil of selected living areas in Italy with the aim to detect the asbestos concentration in air and subsequent risk of exposure for the population in ambient living environments, and to assess the nature of the other mineral phases composing the particulate matrix. Some areas were sorted out because of the presence of asbestos containing materials on site whereas others were used as blank spots in the attempt to detect the background environmental concentration of asbestos in air. Because the concentration of asbestos in ambient environments is presumably very low, and it is well known that conventional low–medium flow sampling systems with filters of small diameter (25 mm) may collect only a very small fraction of particulate over a short period, for the first time here, an intense monitoring activity was conducted with a high flow sampling system. The high flow system requires the use of large cellulose filters with the advantage that, increasing the amount of collected dust, the probability to collect asbestos fibers increases. Both the protocol of monitoring and analysis are novel and prompted by the need to increase the sensitivity towards the small number of expected fibers. With this goal, the collection of fall-out samples (the particulate falling into a collector filled with distilled water during the monitoring shift) and soil samples was also accomplished. The analytical protocol of the matrix particulate included preliminary X-ray powder diffraction (XRPD), optical microscopy and quantitative electron microscopy (SEM and TEM). Correlations with climatic trends and PM10 concentration data were also attempted.The surprising outcome of this work is that, despite the nature of the investigated site, the amount of dispersed asbestos fibers is very low and invariably lower than the theoretical method detection limits of the SEM and TEM techniques for identification and counting of asbestos fibers. The results are compared to the literature data worldwide and an updated model for asbestos fibers dispersion in ambient environments is proposed.  相似文献   
214.
Background, Aim and Scope Agricultural industrial wastes can frequently be used as raw materials in the production of bio-fuels. Olive-oil milling wastewater is considered as one of the most polluting agro-industrial residues, but fortunately due to its high content of organic matter, it has the potential to be a valuable starting material to obtain bio-ethanol via fermentation with Saccharomyces cerevisiae. The fermentation of olive-oil milling wastewater has been demonstrated with good yield of ethanol (8-12%v/v) once the level of reducing sugars is appropriate and the phenolic fraction, which inhibits the yeast, is removed. Materials and Methods: - Results: - Discussion: - Conclusions: - Recommendations and Perspectives: -  相似文献   
215.
The results are presented of a survey planned to assess the presence of high concern chemicals in sediments collected in a northern sector of the Adriatic sea neighboring the Venice lagoon. For the assessment, persistent marker chemicals were selected from the families of polycyclic aromatic hydrocarbons, polychlorobiphenyls, polychlorodibenzo-p-dioxins (PCDDs), polychlorodibenzofurans (PCDFs), and chlorinated pesticides. Based on the chemical-specific concentrations and PCDD+PCDF profiles determined in the sediments analyzed, dumping zones appear to have existed approximately 5-6km away from lagoon shoreline. Contamination levels exceed the quality criteria established by the pertinent Italian national regulation at many sampling sites, eventually reflecting ("fingerprinting") industrial activities once performed in the industrial settlement of Porto Marghera within the Venice lagoon. In coastal samples, concentration levels appear to be lower than those determined at offshore sampling sites.  相似文献   
216.
Forests were shown to play an important role in influencing atmospheric concentrations and transport of persistent organic pollutants (POPs) in the environment. World forests cover more than 4 billion hectares and contain up to 80% of the above ground organic carbon. Given the lipophilic nature of POPs, this suggests that forests can influence the environmental fate of POPs at a global scale. POP accumulation in forest canopies still presents points of concern given the complexity of these ecosystems. In particular, the role of ecological parameters such as LAI (leaf area index) and SLA (specific leaf area) and their dynamics during the growing season was not sufficiently investigated yet. This paper reviews, compares and interprets a unique case study in which air and leaf concentrations and deposition fluxes for selected polychlorinated biphenyls (PCBs) were measured in three different forest types exposed to the same air masses. In order to trace the air-leaf-soil path of these compounds, a dynamic model of POP accumulation into forest canopy was applied. The dynamics of the canopy biomass strongly affected the trend of leaf concentration with time. Growth dilution effect can prevent the more chlorinated compounds from reaching the partitioning equilibrium before litter fall, while the more volatile compounds can approach equilibrium in the range of few weeks. An amount of up to 60 ng of PCBs per square metre of ground surface was predicted to be stored in each of the selected forests at fully developed canopy. Dry gaseous deposition fluxes to forest canopy were estimated to reach a maximum value of about 0.5-1.5 ng m(-2) d(-1) during the spring period.  相似文献   
217.
Tree cores (Pinus nigra ssp. laricio) and leaves (Castanea sativa) from the flanks of Mount Etna, Sicily were analysed by ICP-MS to investigate whether volcanogenic cations within plant material provide an archive of a volcano's temporal and spatial depositional influence. There is significant compositional variability both within and between trees, but no systematic dendrochemical correlation with periods of effusive, explosive or increased degassing activity. Dendrochemistry does not provide a record of persistent but fluctuating volcanic activity. Foliar levels of bioaccumulated cations correspond to modelled plume transport patterns, and map short-term volcanic fumigation. Around the flanks of the volcano foliar variation is greater for volatile cations (Cs, Cd, Pb) than for lithophilic cations (Ba, Sr), consistent with trace-metal supply from volcanic aerosol during quiescent periods.  相似文献   
218.
Australia is experiencing mounting pressures related to processes of urbanisation, biodiversity loss and climate change felt at large in cities. At the same time, it is cities that can take the leading role in pioneering approaches and solutions to respond to those coupling emergencies. In this perspective piece we respond to the following question: What are the required transformations for prioritising, valuing, maintaining and embracing nature in cities in Australia? We adopt the mission framework as an organising framework to present proposed pathways to transform Australian cities as nature-positive places of the future. We propose three interconnected pathways as starting actions to steer urban planning, policy and governance in Australian cities: First, cities need to establish evidence-based planning for nature in cities and mainstream new planning tools that safeguard and foreground urban nature. Second, collaborative planning needs to become a standard practice in cities and inclusive governance for nature in cities needs to prioritise Aboriginal knowledge systems and practices as well as look beyond what local governments can do. Third, for progressing to nature-positive cities, it is paramount to empower communities to innovate with nature across Australian cities. Whilst we focus on Australian cities, the lessons and pathways are broadly applicably globally and can inspire science-policy debates for the post COP15 biodiversity and COP26 climate change implementation processes.  相似文献   
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