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31.
Complex interaction between anthropogenic activities, air quality and human health in urban areas, such as in Cracow sustains the need for the development of an interdisciplinary and integrated risk-assessment methodology. In such purpose, we propose a pilot study performed on asthmatics and based on a combined use of a biomarker, such as metallothionein 2A (MT-2A) in the characterization of human exposure to one or a mixture of pollutants and of Geographical Information Systems (G.I.S.) which integrates climatic and urban anthropogenic parameters in the assessment of spatio-temporal dispersion of air pollutants. Considering global incidence of air pollution on asthma and on peripheral blood lymphocytes MT-2A expression should provide a complementary information on biological risks linked to urban anthropogenic activities. Such study would help for the establishment of a sustainable development in urban areas that can maintain the integrity of air quality and preserve human health.  相似文献   
32.
This paper identifies factors that influence the demand for a bass fishing trip taken in the southeastern United States using a hurdle negative binomial count data model. The probability of fishing for a bass is estimated in the first stage and the fishing trip frequency is estimated in the second stage for individuals reporting bass fishing trips in the Southeast. The applied approach allows the decomposition of the effects of factors responsible for the decision to take a trip and the trip number. Calculated partial and total elasticities indicate a highly inelastic demand for the number of fishing trips as trip costs increase. However, the demand can be expected to increase if anglers experience a success measured by the number of caught fish or their size. Benefit estimates based on alternative estimation methods differ substantially, suggesting the need for testing each modeling approach applied in empirical studies.  相似文献   
33.
The paper presents noise reduction (NR) of spiral ducts as a result of computational modeling of acoustic wave propagation. Three-dimensional models were created with the finite element method in COMSOL Multiphysics version 3.3. Nine models of spiral ducts with 1-9 spiral leads were considered. Time-harmonic analysis was used to predict NR, which was shown in spectral and interval frequency bands. Spiral duct performance can be seen as a comparison of NR before and after a change from a circular to a spiral duct.  相似文献   
34.
Over the last years, we have been testing a hypothesis that molecular mechanisms of nickel-induced carcinogenesis include interactions of this metal with major chromatin components; DNA, histones, and protamines. Our investigations using synthetic peptide models have resulted in identification of nickel-binding sites in core histones H3 and H2A and in protamine P2. These are: the internal -Cys110-AIH- motif in histone H3: the C-terminal-E121-SHHKAKGK "tail" motif in histone H2A; and the N-terminal RTH- motif in protamine P2. Ni(II) bound to the H3 and P2 motifs enhances oxidative DNA base damage by H2O2. In contrast, Ni(II) complex with the H2A "tail" is not redox active. However, at pH 7.4, it undergoes hydrolysis yielding a new complex, Ni(II)-SHHKAKGK, reactive with H2O2 and capable of mediating DNA oxidation. The "tail" cutting of H2A has also been observed in cells cultured with Ni(II). In Ni(II) complex with the protamine P2 peptides, H2O2 causes degradation of the metal-binding His3 and the distant Tyr8 residues. This site-specificity results from a long-range structuring effect of Ni(II) on its protamine ligand. In conclusion, Ni(II) binding to some chromatin proteins in somatic and sperm cells may result in oxidative and structural damage to the proteins and DNA. These effects may alter the fidelity of DNA replication and gene expression and thus facilitate carcinogenesis, including paternally-mediated cancer in the progeny.  相似文献   
35.
The emission factors of mercury and calculation of annual emission into the atmosphere from different industrial sources in Poland are presented. The emission factors in turn depend on mercury concentration in raw materials, as well as on the character of a technological process. The combustion of hard coal and lignite was found to be the major emission source of mercury into the atmosphere.  相似文献   
36.
The studies on elemental carbon content in the atmospheric air, performed at the air monitoring station in Katowice (Poland), have revealed violations of allowable maximum average annual and diurnal concentrations. Elemental carbon is introduced into the atmosphere mainly as soot generated from combustion processes. This work presents the determination of elemental carbon in emission generated from coal combustion processes.  相似文献   
37.
Baran W  Makowski A  Wardas W 《Chemosphere》2005,59(6):853-859
One of the problems connected with wastewater treatment by the photocatalytic method in the presence of TiO2 suspension is necessity of the later catalyst separation. The method proposed by us for this purpose, consists in the usage of coagulation of TiO2 suspension with the aid of FeCl3, particularly in the cases when addition of the salt is used in order to intensification of the photocatalytic process. The effects of the TiO2 separation were studied from the mixtures, after photocatalytic Acid Orange 7 degradation, with dosage of FeCl3 at different stages of the process. The coagulation was carried out at different pH values as well as different FeCl3 concentrations. It was stated that nearly 100% of separation and simultaneously, nearly 100% of decolouration of the examined Acid Orange 7 solutions after their illumination in the presence of TiO2/FeCl3 and coagulation which was produced only by increasing of pH of the obtained mixtures, were nearly possible.  相似文献   
38.
The aim of this work is to investigate the application of fly ash adsorbent for removal of arsenite ions from dilute solution (100–1,000 ppm). Experiments were carried out using material from the “Turów” (Poland) brown-coal-burning power plant, which was wetted, then mixed and tumbled in a granulator to form spherical agglomerates. Measurements of arsenic adsorption from aqueous solution were carried out at room temperature and natural pH of fly ash agglomerates, in either a shaken flask or circulating column, to compare two different methods of contacting solution with adsorbent. Adsorption isotherms of arsenic were determined for agglomerated material using the Freundlich equation. Kinetic studies indicated that sorption follows a pseudo-second-order model. Preferable method to carry out the process is continuous circulation of arsenite solution through a column.  相似文献   
39.

Background

Impact of two widely used commercial herbicides, i.e. Aminopielik D 450 SL and Chwastox 300 SL, on the uptake and translocation of selected heavy metals in wheat plants Triticum aestivum L. cultivated in the laboratory pot experiments was investigated. Mineral-humus, loamy sand soil representative for the central part of Poland was applied. Bioavailable, exchangeable and total forms of Cd, Co, Cu, Zn, Pb, and Mn were determined. Transfer coefficients, translocation, and bioaccumulation factors illustrating metal migration in the plant were investigated.

Results

Administration of commercial herbicides significantly altered heavy metals uptake by wheat in a way distinctively different than that observed for the parent chemically pure synthetic auxins, i.e. 2,4-D and MCPA. In particular, Aminopielik D 450 SL and Chwastox 300 SL prompted heavy metals accumulation in roots as indicated by their high transfer coefficients. Further transport to above ground part of the plant was limited and element dependent.

Conclusions

This work clearly shows that commercial herbicide formulations may act in a distinctively different way than pure active ingredients alone.
  相似文献   
40.
Sulfonamides (SAs) are one of the oldest groups of veterinary chemotherapeutic agents. As these compounds are not completely metabolized in animals, a high proportion of the native form is excreted in feces and urine. They are therefore released either directly to the environment in aquacultures and by grazing animals, or indirectly during the application of manure or slurry. Once released into the environment, SAs become distributed among various environmental compartments and may be transported to surface or ground waters. The physicochemical properties of SAs, dosage and nature of the matrix are the factors mainly responsible for their distribution in the natural environment. Although these rather polar compounds have been in use for over half a century, knowledge of their fate and behavior in soil ecosystems is still limited. Therefore, in this work we have determined the sorption potential of sulfadimethoxine and sulfaguanidine on various natural soils. The influence on sorption of external factors, such as ionic strength and pH, were also determined. The sorption coefficients (Kd) obtained for the sulfonamides investigated were quite low (from 0.20 to 381.17 mL g−1 for sulfadimethoxine and from 0.39 to 35.09 mL g−1 for sulfaguanidine), which indicated that these substances are highly mobile and have the potential to run off into surface waters and/or infiltrate ground water. Moreover, the sorption of these pharmaceuticals was found to be influenced by OC, soil solution pH and ionic strength, with higher Kd values for soils of higher OC and lower Kd values with increasing pH and ionic strength.  相似文献   
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