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1.
Lichens have long been regarded as bioindicators of air pollution, and structural studies typically have indicated negative impacts in highly polluted areas. In this research, Parmelia sulcata and Platismatia glauca were collected from one clean and two polluted sites in the Pacific Northwest forests of the United States to investigate the anatomical and ultrastructural responses of relatively resistant lichens to moderate air pollution. Light microscopy of polluted materials revealed only slight increases in the algal cell proportions of the thallus, and a decrease in the fungal cells of the medulla. Using transmission electron microscopy, increased lipid droplets in the cytoplasm and an increase in the cell wall thickness of the photobionts were found in the polluted lichens. These results were compared with physiological data in which the net carbon uptake did not show any significant differences; however, the total chlorophyll content was heightened in the polluted samples. The increased total chlorophyll content and the absence of any changes in the algal cell proportions of the polluted samples suggest that the photobionts possessed a higher chlorophyll content per unit volume of the photobiont at polluted sites. The results also indicate that lichens have altered their storage allocation in different cellular compartments. This may be a result of symbiotic readjustment(s) between the photobiont and the mycobiont. In comparison with the physiological results from these two species, these changes do not represent damaging effects by low-level air pollution.  相似文献   

2.
The atmospheric pollution of São Paulo city is a serious problem due to the expansion of industrial area, increasing number of vehicles and population density. This work presents results obtained in the analysis of lichens collected in different sites of São Paulo city and in non-polluted areas of Atlantic Forest. Concentrations of twenty elements were determined in Canoparmelia texana species and comparisons were made between the results obtained in lichens from different sites. High concentrations of the elements As, Ba, Cd, Co, Cr, Fe, La, Mn, Sb and Zn were found for samples collected in sites located near industries and petrochemical plant. Br and Sb concentrations were also high in lichens from sites affected by vehicular emissions.  相似文献   

3.
Alkaline digestion with sodium hydroxide/methanol/pentane, Soxhlet extraction with methanol/dichloromethane, and ultrasonication with methanol/dichloromethane were applied to subsamples of three surface sediments polluted by oily drill cuttings to different levels (about 50, 1000 and 25 000 mg kg?1 hydrocarbon pollution). For the two most polluted sediments the three methods were not significantly different in their ability to extract petroleum hydrocarbons from the sediments, at a 90% confidence level. The amounts extracted from the least polluted sediments using ultrasonication was, however, significantly above the amounts obtained by the other two methods. The average relative standard deviations increased in the order Soxhlet method (4.5%), alkaline digestion (12.4%) and ultrasonication (16.1%). Small differences in the relative amounts of some individual components were observed in the moderately polluted sediment.  相似文献   

4.
Instrumental Neutron Activation Analysis (INAA) has been applied for the determination of 8 rare earth elements (REE) in sediment cores collected from stations of polluted and unpolluted areas of Northern Saronikos Gulf. The REE determined in cores are: La, Ce, Sm, Eu, Tb, Dy, Yb and Lu. Higher levels of all REE were found in the cores from polluted areas of N. Saronikos Gulf as compared with those from unpolluted areas. Different vertical profiles of REE were found in the cores from two stations of polluted areas which indicate that REE may distinguish pollution sources.  相似文献   

5.
Tuzla is among the most polluted cities of Bosnia and Herzegovina. The main source of pollution in the area is soil heavily contaminated by mercury released from a former chloralkali plant. This paper is focused on the characterization of mercury contaminated soil and air surrounding the chloralkali plant. In soil, the mobility and transformation of mercury were investigated by sequential extraction, while the methylation and reduction potentials were determined by the use of a radioactive tracer. Mercury emission from soil was determined by laboratory and by flux chamber measurements in the field. In addition, mercury concentrations in air were estimated by the analysis of air and the transplanted lichen Hypogymnia physodes. Mercury in soils in the vicinity of the chloralkali plant exceeded the background value by a factor of more than 3000. The fractionation of mercury in surface soil by sequential extraction showed that the mercury in soil was primarily bound to organic matter and a fraction containing elemental mercury and mercury (I) chloride is also significant. The obtained methylation and reduction potentials are low. The mercury flux from soil was estimated by two approaches. Fluxes of up to 8000?ng/m2/day were measured at the most polluted site; evaporation from soil was shown to be the primary source of elevated mercury in air. Air concentration mapping also revealed other sources of mercury; the most likely is the 715 MW coal power plant in the vicinity of former chloralkali facility.  相似文献   

6.
Polybrominated diphenyl ether (PBDE) concentrations were determined in marine sediment samples collected from 7 different locations around Thermaikos Gulf in north Greece. PBDEs were detected in all sampling sites and their average total concentration (ΣPBDEs) ranged from 0.26 to 4.92?ng?g?1?d.w. Concentrations were an order of magnitude higher in locations outlining the inner part of the Gulf, which were also closer to industrial areas, sewage treatment plant discharges, the city's harbour and landfill area. These findings suggest pollution in the aquatic ecosystem from industrial and urban activities in the area. Congener profiles exhibit predominance of BDE-209, while concentrations of other PBDE congeners were usually lower, when compared to similar studies from other countries globally, indicating that Thermaikos Gulf is among the low-polluted areas. Statistical analysis showed significant differences among the higher polluted sampling stations. Statistically significant differences also existed between sampling stations with high and low PBDE concentrations. Correlations between congeners suggested local contamination sources; however, specific point sources of pollution were not established.  相似文献   

7.
Abstract

Factor Analysis (FA) is applied to tentatively establish either jhe sources of pollution in the groundwater in a delimited zone in Catalonia which has been polluted by permeation with non-controlled wastewaters or the groundwater evolution with time in this area. Three types of chemical analysis were considered: general parameters indicating the chemical quality of water, inorganic micropollutants and organic micropollutants. These analyses were carried out with forty-five samples collected in three different periods, and eleven parameters were considered. From the final solutions of the FA method applied several factors were retained for the different sampling periods and these factors were related to different sources of pollution. FA has proved to be more useful when punctual pollution incidents takes place rather than when groundwater evolution with time is studied.  相似文献   

8.
The following metals: Al, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn were determined by inductively coupled plasma - atomic emission spectroscopy (ICP-AES) in fluvial sediments of Rosandra Creek, using two different, strong and mild sediment decomposition methods. The purpose was to obtain information about the contamination by metals and distribution paths of pollutants in the area crossed by Rosandra Creek: this little river is the unique epigeous watercourse in the Italian Karst and very few data can be found in literature. In this area, we can find a natural park, but also agricultural activities and an industrial district that was recently defined as "polluted site of national interest". By comparing the results of the strong and mild extraction we have obtained the percentage of extraction and enrichment factors for each metal in the different sediments of the sites R2 and R3 exposed to pollution, while the site R1 was considered as a pristine one because situated in the natural park. The computed enrichment factors are generally not very high, but copper, lead and zinc have factors that require attention. The principal component analysis (PCA) shows that the typically anthropogenic metals (as Cr, Pb, Cu and Zn) constitute the first factor, while the lithogenic metals, as Fe and Ni, constitute the second one; moreover the score plots permit to classify and distinguish the 3 sites: site R3, possibly the more exposed to contamination, has high scores both for anthropogenic and lithogenic metals.  相似文献   

9.
Beijing,the capital of China,frequently suffers from the high levels of ozone in summer.A 3-D regional chemical transport model,the Comprehensive Air Quality Model with extensions(CAMx),has been used to simulate a heavy O3 pollution episode in Beijing during June 26―July 2,2000.Ozone Source Apportionment Technology(OSAT) and Geographic Ozone Assessment Technology(GOAT) were applied to quantify the contributions of the precursor emissions from different regions to O3 concentrations in Beijing,to identify the...  相似文献   

10.
Samples of the mosses Hylocomium splendens and Pleurozium schreberi, collected in the summer of 1998, were used to study the atmospheric deposition of heavy metals and other toxic elements in the Chelyabinsk Region situated in the South Urals, one of the most heavily polluted industrial areas of the Russian Federation. Samples of natural soils were collected simultaneously with moss at the same 30 sites in order to investigate surface accumulation of heavy metals and to examine the correlation of elements in moss and soil samples in order to separate contributions from atmospheric deposition and from soil minerals. A total of 38 elements (Na, Mg, Al, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Zn, As, Se, Rb, Sr, Zr, Mo, Sb, Cs, Ba, La, Ce, Nd, Sm, Eu, Gd, Tb, Dy, Yb, Hf, Ta, W, Au, Th, U) in soil and 33 elements Na, Mg, Al, Cl, K, Ca, Sc, V, Cr, Mn, Fe, Co, Ni, Zn, As, Se, Br, Rb, Ag, Sb, Cs, Ba, La, Ce, Sm, Tb, Yb, Hf, Ta, W, Au, Th, U) were determined by epithermal neutron activation analysis. The elements Cu, Cd and Pb (in moss samples only) were obtained by atomic absorption spectrometry. VARIMAX rotated principal component analysis was used to identify and characterize different pollution sources and to point out the most polluted areas.  相似文献   

11.
北京地区臭氧污染的来源分析   总被引:31,自引:1,他引:31  
光化学烟雾污染是影响北京地区夏季空气质量的一个重要环境问题.利用区域空气质量模(CAMx)对2000年6月底至7月初发生在北京地区的臭氧污染过程进行模拟,运用臭氧源识别技术(OSAT)和地区臭氧评估技术(GOAT),量化了不同地区的污染源排放对北京市城近郊区臭氧污染的贡献,探讨了周边地区排放的臭氧贡献方式问题,分析了北京地区臭氧污染的化学机制特征.研究表明,北京地区臭氧污染分布存在显著差异,并且具有明显的区域性特征,定陵地区的超标臭氧主要受到城近郊区烟羽的严重影响(占55%),城近郊区则除了受到北京市的前体物排放影响外(占46%),来自天津市、河北省南部地区的贡献往往也占有重要份额;周边地区对北京市城近郊区的贡献中,直接输入的臭氧约占七层,其余部分以输入前体物的方式贡献臭氧;北京城近郊区的臭氧生成主要受挥发性有机物控制,而在远郊区县和农村地区臭氧生成对氮氧化物变得更为敏感.对北京地区臭氧污染的源排放控制,需要综合考虑各种臭氧来源和不同贡献方式的重要性,以及臭氧生成机制的变化规律.  相似文献   

12.
Epiphytic bromeliadTillandsia usneoides was used as a biomonitor of metal atmospheric pollution in the city of São Paulo, Brazil. The samples were collected from an unpolluted area and were exposed for 8 weeks in 10 sites of the city and in a control site. The data obtained showed that the control site presented lower concentration for most elements analyzed and the highest concentrations of Na, Cl, Br, K. The highest concentrations of Zn, Cu and V were observed in stations submitted to industrial and vehicular sources. The results obtained for rare earth elements, Al, Fe, Mg, Mn, Rb and Sc indicate mineral dust origin. The elements Ba, As and Sb presented higher values in stations near streets with heavy traffic.  相似文献   

13.
Summary. Ternary compounds of the type (M,M′)xAy where M and M′ are early transition metals of the groups 4–6 and A is a main group element of the groups 14–16 are showing interesting substitution mechanisms among the metal atoms ranging from classical and partially ordered solid solution phases to ternary compounds showing differential fractional site occupation. In these compounds the transition metals show mixed site occupation at the metal positions in combination with pronounced site preferences leading to varying metal mixtures at crystallographically independent sites. The connection between partial ordering and the differences in the local coordination of the respective lattice sites is discussed. Chemical bonding arguments obtained from electronic calculations using the extended Hückel approach are used to understand the observed distribution of the metals over the respective lattice sites and allow a qualitative prediction of site preferences. A thermodynamic model was applied in order to investigate the observed substitution mechanism and Gibbs energies for the occupation of the lattice sites with different metal atoms could be obtained by adjusting the model parameters to the experimentally observed site fractions.  相似文献   

14.
Instrumental neutron activation analysis was applied for the determination of trace elements in Canoparmelia texana species collected mnonpolluted areas of Atlantic Forest and in six sites of Santo André Municipality, SP, Brazil. Concentrations of As, Ba, Br, Ca, Cd, Cl, Cr, Cs, Co, Fe, K, La, Mn, Na, Rb, Sb, Sc, Se, U, and Zn were determined and comparisons were made between the results obtained in lichens from different sites.  相似文献   

15.
In order to find out if there is a relation between atmospheric particulate matter composition and human health effects, metals and other elements measurement are performed. Analysis of atmospheric aerosols collected in filters is the usual method to achieve this task. Biological monitors provide an advantageous alternative way of sampling, since there is no need of special sampling devices, and accumulation time can be as long as desired. In this study, Tillandsia usneoides a reliable air pollution biological monitor that occurs naturally throughout Mexico was used to monitor air quality of Tula–Tepeji corridor at central Mexico. This area is considered critical zone because of atmosphere contaminants high concentration. Some biomonitors were transplanted from a clean environment to four sites at the Tula corridor. Plants samples were collected every two weeks from February to April 2008. PM10 sampling in filters was also performed simultaneously at three locations where T. usneoides was transplanted, for a comparison. Chemical composition was determined by PIXE. Results showed that T. usneoides incorporates anthropogenic elements reaching maximal levels after 6 to 10 weeks approximately. Since results obtained with biomonitors agree with those obtained with aerosol filters, T. usneoides could be employed as a first approximation to provide insights of the atmospheric pollution level previous to a detailed study using filters.  相似文献   

16.
This study investigates the soil and wild plants of the Pb-Zn sulfide bearing mineralized zone of Indian plate (IP) in the Pazang and Lahor sites, Kohistan region, northern Pakistan. Soil and plants were analyzed for major cations (Na, K, Ca, Mg, Fe, Mn) and heavy metals (Pb, Zn, Cd, Cu, Cr, Ni, Co) concentrations by using atomic absorption spectrometer. Metal concentrations were used to quantify pollution contamination factors such as pollution load index (PLI) and plant bioaccumulation in soil and plants developed in mineralized zones in the Lahor and Pazang sites and an unmineralized zone (reference sites) of the Besham area. Soil and plants of the mineralized zone and surrounding areas have higher heavy metal (HM) contamination (P < 0.01) as compared to the reference site, which can be attributed to the dispersion of metals due to mining. Furthermore, in mineralized zones, the Lahor site was more contaminated than the Pazang site. This high HM contamination may pose potential threats to local communities of Kohistan region. The results also showed that plant species (Plectranthus rugosus, Rumex hastatus, Fimbristylis dichotoma, Heteropogon conturtus and Myrsine Africana) were the best HM accumulators.  相似文献   

17.
应用地质累积指数评价南昌市城市污泥重金属污染   总被引:5,自引:0,他引:5  
应用地质累积指数对南昌市城市污泥(包括污水处理厂污泥和纸厂废水处理污泥)的重金属污染进行了分析评价。结果表明,城市污泥重金属中Pb、Cr按地质累积指数分级均为0,属无污染;As地质累积指数为0~1之间,表现为无污染~中度污染;青山湖污水处理厂污泥主要的重金属污染元素为Cd、Hg、Cu、Zn,其平均的地质累积指数为2~4,表现为中度污染~强污染。  相似文献   

18.
Abstract— A radiative transfer model is used to study the effect of stratospheric ozone depletion and tropospheric pollution on UVB (280-315 nm) radiation in the troposphere at midiatitudes of the Northern Hemisphere. The difference in the vertical distribution of UVB radiation for a range of pollution conditions typical for remote clean and more polluted sites on cloudless summer days is shown. The changes in downward UVB irradiance, UVB actinic flux, DNA-weighted UV radiation and photodissociation frequency of ozone at the earth's surface are quantified in relation to stratospheric ozone depletion and typical ranges of tropospheric pollutants (ozone [O3], sulfur dioxide [SO2] and aerosols) in nonurban polluted regions. The results show that near the earth's surface, in non-urban polluted regions, an increase of tropospheric pollution, which occurred over the last 50-100 years, has cancelled the effect of an increase of UVB radiation due to stratospheric ozone depletion that has occurred since the late 1970s. The results hold for summer conditions and the decrease of UVB radiation is most pronounced in the polluted boundary layer. At higher altitudes the effect of tropospheric pollution on UVB radiation is far less. Prior to 1970 it was mainly tropospheric pollution that altered UVB radiation at the surface of the earth. In addition, since the late 1970s enhanced UVB radiation reaching the top of the troposphere, due to stratospheric ozone depletion, also had an impact on UVB levels in the troposphere.  相似文献   

19.
We have investigated the concentrations of REEs in fern leaves collected indifferently to the fern species from 9 sampling sites in Japan using INAA. The results indicated a large variation in the values obtained between fern leaves. In the present investigation we applied the same analytical method on the samples (Blechnaceae, a kind of fern, mature and developing leaves were collected from the same plant) restrictively gathered from the University Forests in Ashiu, Kyoto University. It was demonstrated that the variations in the REE concentrations decreased by one to two order of magnitude, and that the REE contents in developing leaves were also one to two orders of magnitude lower than those in mature leaves. It can be considered that fern accumulates REEs with their growth stages.  相似文献   

20.
CO(2) samples were collected from air at three sites in Hungary for comparison of polluted and background areas. In order to reduce the uncertainties caused by the varying amount of N(2)O, a gas chromatography (GC)-based vacuum separation was applied. The reliability of the procedure was demonstrated by careful standardization and comparison with global network data. The stable isotope data show complex diurnal and seasonal variations that can be explained by fractionations during photosynthesis and respiration. The isotopic characteristics of pollution-derived (anthropogenic) and biogenic CO(2) appear to be indistinguishable at the study sites. However, the sites at unpolluted areas reveal a seasonal variation in the carbon isotope composition of biogenic CO(2) that may be related to changes in soil biogenic activities. The atmospheric background CO(2) shows constant delta(13)C in the region. Finally, the study demonstrates the need for careful standardization of sampling in order to make the data obtained from different sampling systems comparable.  相似文献   

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