A method is presented for the design of multi-pollutant air quality monitoring networks (AQMN). This technique leads to an optimal network, i.e. a network providing a maximum of information with a minimum of measurement devices. The spatial correlation analysis technique is used to compare the information given by the potential sites that may form the network. The concept of potential of violation is defined to take into account the number of times that the maximum emission values tolerated by law are exceeded. Both objectives are weighted automatically through an adjustable parameter, b, for which an estimation procedure has been developed in this study, depending on the purpose of the network. Several methods are described, allowing simultaneous consideration of different pollutants. As an illustration of these methods, a number of air quality monitoring networks is designed to perform an analysis of the environmental impact due to a hypothetical potash processing plant and two thermal power stations. 相似文献
In order to control the quality of platinum, palladium and rhodium determinations in road dust, the Standards, Measurements and Testing Programme (formerly BCR) of the European Commission has started a project, the final aim of which is to certify a road dust reference material for its contents of platinum group elements. The first part of this project consisted of an interlaboratory study, which aimed to test the feasibility of the preparation of a candidate road dust reference material and to detect and remove most of the pitfalls observed in platinum, palladium and rhodium determinations. This paper presents the main results of this interlaboratory study carried out prior to the certification campaign. The concordance of the data obtained by the participating laboratories for the three elements was considered to reflect the state-of-the-art and was encouraging enough to decide on the organization of a certification campaign to be conducted during the year 2000. The progress made with respect to the analytical state-of-the-art for these elements will be of great benefit to the quality of measurements carried out in environmental monitoring in this particular field. 相似文献
A sublethal dose (5 mg L-1) of phenol was applied in the experiment. Liver and pancreas samples were taken at 24, 48, 72, and 96 hr for electron microscopy. The following alterations were manifested during the experiment: amitosis, irregular nuclear forms, decrease of chromatin, nucleolar segregation and numerous phagosomes and autophagic vacuoles in the cytoplasm. After 72 hr, large empty vacuoles also developed in the cells. The rEr was often dilated, and the accumulation of paraprotein crystals in their lumen was also common. All these alterations prove the serious cytopathological effects of phenol on the metabolism of parenchymal cells. 相似文献
The interaction of heavy metals (HgCl2, CdCl2, CuCl2, PbCl2 and ZnCl2) and neurotransmitters (ACh, 5HT and DA) was studied on the excitable membrane of identified neurons of Lymnaea stagnalis and Helix pomatia. It was shown that,
The excitability and chemosensitivity of molluscan neurons were modified under the influence of the heavy metals Hg2+, Cd2+, Cu2+, Pb2+ and Zn2+.
Change in excitability to transmitters occurred as a potentiation or depression of the evoked response both in duration of membrane polarization and in frequency of spike activity.
The chemosensitivity changes in various ways, namely:
excitatory effect was totally eliminated;
one component of the effect was depressed.
Different neurons may show different reactions to the same heavy metal.
There were differences in the effects of various heavy metals. Hg2+ has a more generalized effect than Cd2+; Cu2+, Pb2+ and Zn2+ were less effective in a number of neurons. The heavy metal effect was dose dependent, too.
Both inward and outward currents, which were evoked by neurotransmitters or voltage induced, were modified in most of the tested neurons. Both an increase and decrease of the membrane permeability occurred in different neurons in response to the same or different heavy metals.
The changes can be interpreted as a result of
direct effect on specific ionic channels;
modification of receptors binding ACh, 5HT, or DA;
modification of intracellular processes responsible for the regulation of membrane permeability.
A study was undertaken, within the framework of a 3 years national project, to assess the content of 13 elements in airborne particulate matter collected in representative zones of the metropolitan area of Buenos Aires. The sampling strategy followed consisted in collecting simultaneously 67 samples of PM10 particulate matter in 9 sampling sites covering an area of about 30 km2 during one week. The collection was performed on ash-free fibre-glass filters using high volume samplers. A combination of aqua regia and perchloric acid was used for leaching metals from filters. Key elements, namely Al, Ca, Cu, Fe, Mn, Mo, Ni, Pb, S, Sb, Sn, Zn and Zr, were determined by inductively coupled plasma-optical emission spectrometry (ICP-OES) and inductively coupled plasma-mass spectrometry (ICP-MS) at micro g g(-1) and ng g(-1) levels. Analyte concentration varied from 130 ng g(-1)(Mo) to over 30%(Ca). Multivariate statistical analysis was performed on the data set including the measured elemental compositions for the monitored period. The atmospheric concentration found for Pb confirms the decreasing levels of this element since the introduction of unleaded gasoline in 1995: 88 ng m(-3)(2001) < 220 ng m(-3)(1997) < 3900 ng m(-3)(1994). The average S concentration above 3 microg m(-3) is somehow unexpectedly high for Buenos Aires since the relatively low S content of liquid fuels and the massive usage of natural gas imply low emissions of this element from combustion activities. To the best of our knowledge, S concentrations are reported for the first time for this city. 相似文献
Environment, Development and Sustainability - This study aims to provide various maps of the evolution, current situation and future lines of sustainability indicators for tourism destinations... 相似文献
Environment, Development and Sustainability - The issues concerning mining have been causing a wide variety of emotions. Objection to and disagreement with new investments, but also social... 相似文献
The effect of light intensity, pH and carbonic anhydrase (CA) inhibitors on photosynthesis of the red marine macroalgae Solieria filiformis (Kützing) Gabrielson, collected from Taliarte (Gran Canaria, Canary Islands) in 1991, has been investigated. Plants taken from the sea (wild phenotype) developed spherical morphology (ball phenotype) after 2 mo culture in aerated tanks. The photosynthetic oxygen evolution in the wild phenotype was saturated at 100 mol photons m-2s-1, while the ball phenotype displayed saturation at 200 mol photons m-2s-1. The inhibitors of total CA activity (6-ethoxizolamide) and extracellular CA activity (dextran-bound sulfonamide) inhibited photosynthesis at pH 8.2, to 90 and 50% respectively, in both phenotypes. No inhibition of the photosynthetic oxygen evolution was detected at pH 6.5. CA activity was associated with both supernatant and pellet fractions of crude extracts of S. filiformis. The rate of alkalization of the medium by the algae was dependent on light intensity. We suggest that carbon dioxide is the general form of inorganic carbon transported across the plasmamembrane in S. filiformis. HCO3 transport into the cell takes place simultaneously by an indirect mechanism (dehydration to CO2 catalyzed by CAext) and by direct uptake. Extracellular (CAext) and intracellular (CAint) CAs are involved in the mechanisms of inorganic carbon assimilation by S. filiformis. 相似文献
Aim. The objective of the present study was to test the psychometric properties, reliability and validity of three job stressor measures, namely, the Interpersonal Conflict at Work Scale, the Organizational Constraints Scale and the Quantitative Workload Inventory. Method. The study was conducted on two samples (N?=?382 and 3368) representing a wide range of occupations. The estimation of internal consistency with Cronbach's α and the test–retest method as well as both exploratory and confirmatory factor analyses were the main statistical methods. Results. The internal consistency of the scales proved satisfactory, ranging from 0.80 to 0.90 for Cronbach's α test and from 0.72 to 0.86 for the test–retest method. The one-dimensional structure of the three measurements was confirmed. The three scales have acceptable fit to the data. The one-factor structures and other psychometric properties of the Polish version of the scales seem to be similar to those found in the US version of the scales. It was also proved that the three job stressors are positively related to all the job strain measures. Conclusions. The Polish versions of the three analysed scales can be used to measure the job stressors in Polish conditions. 相似文献
Objective: This article develops and validates a new methodology and tool for rescue assistance in traffic accidents, with the aim of improving its efficiency and safety in the evacuation of people, reducing the number of victims in road accidents.
Method: Different tests supported by professionals and experts have been designed under different circumstances and with different categories of damaged vehicles coming from real accidents and simulated trapped victims in order to calibrate and refine the proposed methodology and tool.
Results: To validate this new approach, a tool called App_Rescue has been developed. This tool is based on the use of a computer system that allows an efficient access to the technical information of the vehicle and sanitary information of the common passengers. The time spent during rescue using the standard protocol and the proposed method was compared.
Conclusion: This rescue assistance system allows us to make vital information accessible in posttrauma care services, improving the effectiveness of interventions by the emergency services, reducing the rescue time and therefore minimizing the consequences involved and the number of victims. This could often mean saving lives. In the different simulated rescue operations, the rescue time has been reduced an average of 14%. 相似文献