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1.
To assess the susceptibility of five varieties of tobacco to ozone, nine rounds of fumigation experiments were performed. These tobacco varieties were exposed to a range of ozone concentrations in a single-pass chamber fumigation system for short periods. A dose of 7.5 pphm did not produce visible injury in any tobacco variety. Tobacco cultivars; Bel-B, Weather Fleck and ZZ100 exhibited no visible injury up to 26 pphm. However, doses in excess of 16 pphm caused visible injury in cultivars Bel-W3 and Dynes. Awareness of the susceptibility levels of these cultivars to ozone assist biological monitoring process in field experiments. Biomonitoring is considered to be a valuable method for ozone assessment for situations where air pollution monitoring by instruments in remote locations is too expensive.  相似文献   

2.
The accumulation efficiency of selected trace elements in the leaves of Melandrium album and Robinia pseudoacacia grown on heavy metal contaminated sites in comparison with a non-contaminated one was evaluated. The study was undertaken to calculate air pollution tolerance index and to determine the contents of selected metabolites: glutathione, non-protein thiols, ascorbic acid, chlorophyll and the activity of antioxidant enzymes: guaiacol peroxidase and superoxide dismutase. Such estimations can be useful in better understanding of plants defense strategies and potential to grow in contaminated environments. The results in the most contaminated site revealed higher contents of metals in M. album leaves, especially Zn, Cd and Pb (3.4, 6 and 2.3 times higher, respectively) in comparison with the R. pseudoacacia. Better accumulation capacity found in M. album was shown by metal accumulation index values. The plants could be used as indicators of Zn, Cd (both species) and Pb (M. album) in the soil. Glutathione content (in both species) and peroxidase activity (in M. album), general markers of heavy metals contamination, were increased in contaminated sites. In most cases in contaminated areas R. pseudoacacia had decreased ascorbic acid and chlorophyll levels. Opposite tendency was recorded in M. album leaves, where similar or higher contents of the above-mentioned metabolites were found. In our study, M. album and R. pseudoacacia proved to be sensitive species with the air pollution tolerance index lower than 11 and can be recommended as bioindicators.  相似文献   

3.
《Atmósfera》2014,27(4):377-384
Clean air is a basic requirement for human health and wellbeing. The Kenya Meteorological Department has established air pollution monitoring activities in various sites in Nairobi, at Dagoretti Corner meteorological station and at Mount Kenya. Different pollutants are measured including ozone. The increased concentration of greenhouse gases in the atmosphere has influenced the weather and climate. This study examined the variations of surface ozone over Dagoretti Corner, Nairobi for a 12-month period ending July 2013, exactly one year after the start of data acquisition. The trend was studied using time series analysis of ozone concentration on both an hourly and monthly basis. The ozone data was then combined with meteorological data and temperature to find correlations between the two. Overall, the air quality of Nairobi, represented by Dagoretti Corner meteorological station is good as compared to the World Meteorological Organization ozone standards. The highest concentration of ozone is observed in the afternoon and the minimum at dawn on a daily basis. On seasonal scale, the highest levels are recorded in the cold months. This information helps to reduce exposure to the gas and thus to reduce its impacts on living things. The study recommends the reduction of exposure to the gas during the times when it has been observed to be highest in order to minimize its impacts.  相似文献   

4.
Air pollution is a grand challenge of our time due to its multitude of adverse impacts on environment and society,with the scale of impacts more severe in developing countries,including China.Thus,China has initiated and implemented strict air pollution control measures over last several years to reduce impacts of air pollution.Monitoring data from Jan 2015 to Dec 2019 on six criteria air pollutants(SO2,NO2,CO,O3,PM2.5,and PM1o)at eight sites in southwestern China were investigated to understand the situation and analyze the impacts of transboundary air pollutants in this region.In terms of seasonal variation,the maximum concentrations of air pollutants at these sites were observed in winter or spring season depending on individual site.For diurnal variation,surface ozone peaked in the afternoon while the other pollutants had a bimodal pattern with peaks in the morning and late afternoon.There was limited trans-port of domestic emissions of air pollutants in China to these sites.Local emissions enhanced the concen-trations of air pollutants during some pollution events.Mostly,the transboundary transport of air pollution from South Asia and Southeast Asia was associated with high concentrations of most air pollu-tants observed in southwestern China.Since air pollutants can be transported to southwestern China over long distances from the source regions,it is necessary to conduct more research to properly attribute and quantify transboundary transport of air pollutants,which will provide more solid scientific guidance for air pollution management in southwestern China.  相似文献   

5.
Multidimensional assessment of air pollution was carried out on trace metals in particulates, desert plant parts and soil collected from the six sites to validate air pollution tolerance index, translocation and bioaccumulation factors. A map indicating the sampled sites was superimposed on the Disper 5.2 software graphical interface to track the particulate dispersion route during the summer and winter seasons. This study showed site-wise orientation of particulates dispersed in the ambient air. Observations indicated the high concentrations of dispersed coarse > fine > ultra-fine particulates in trace metals analyzed from selected desert plants and in the soil especially during winter than in the summer seasons. High air pollution tolerance index was observed in the sequence of Calatropis gigantean > Portulaca oleracea > Citrullus collocynthis > Rumex vesicarius > Bienertia sinuspersici > Tribulus terrestris. Assessment of translocation and bioaccumulation factors labeled these desert plants as hyper-accumulators. The synergistic effect of the translocation and bioaccumulation factor in the various plants and the pollution levels for a given geographical location provides insight management to mitigate air pollution and landscape designers to grow tolerant species and protect sensitive plants from air pollution.  相似文献   

6.
青藏高原现生禾本科植物的δ13C与海拔高度的关系   总被引：14，自引：5，他引：14  
文章通过分析青藏高原4种C3禾本科植物碳同位素值随海拔高度的变化,发现穗三毛(Trisetumspicatum),垂穗鹅观草(Roegnerianutans),紫花针茅(Stipapurpurea),垂穗披碱草(Elymusnutans)的碳同位素值随海拔高度增加而变重的趋势明显,平均每增高1km变重1.37‰,其中Trisetumspicatum和Roegnerianutans的碳同位素值随海拔高度增加而变重的趋势更为显著。研究认为温度和大气CO2分压是引起C3植物碳同位素值随海拔高度变化的主要因素。另外,研究发现一些C4植物的生长高度可以达到海拔4000m以上,最高可达海拔4520m。  相似文献   

7.
This paper presents the analysis and interpretation of ambient particulate matter concentrations measured as PM10 at a network of six air monitoring stations in Kathmandu valley during the years, 2003 through 2005. The purpose was to understand the pollution trends associated with different areas considering levels particulate matter concentrations representing the ambient air quality of Kathmandu valley. The study indicate that particulate concentrations (PM10) measured are persistently higher at air sampling sites representing roadside areas compared to the background sites. The inter-station network variability with respect the particulate pollution suggests optimizing resources. The comparison of annual average PM10 concentration observed at six air-monitoring sites in Kathmandu Valley with standard annual average concentration prescribed by World Health Organization as well as Europe Union indicates serious PM10 pollution in Kathmandu valley.  相似文献   

8.
为查明场地污染分布特征,需对场地土壤和地下水进行钻探取样,按规范的检测指标进行逐一测试。在初查和详查阶段将获得大量的土壤和地下水污染数据,数据样本数量大、监测指标多,数据结构复杂,如何从场地大数据中提取价值信息已成为研究热点。以某有机污染场地为例,基于自组织映射神经网络（SOM）和K均值算法开展大数据分析,深入探讨地下水和土壤中各污染指标间的相关性。结果表明:（1）基于自组织映射神经网络的大数据分析可快速挖掘复杂多维的污染场地监测数据,有效完成关键信息的提取;（2）地下水中污染检出指标存在显著的聚类特征,同一聚类中的污染指标具备相似的空间分布特征。对场地污染物检测采取先分类后分级的优化筛选策略,减少污染物检测指标数目,从而有效降低场地检测费用;（3）土壤和地下水中污染检出指标存在良好的空间相关性,这与该污染场地地下水渗流速度缓慢有关。土壤和地下水污染检出指标空间分布的相关性,有助于场地污染源的追溯。  相似文献   

9.
Beer  Tom 《Natural Hazards》2001,23(2-3):157-169
Meteorological hazards are usually considered to be tropical cyclones, droughts, hail-storms, severe storms and their effects such as tsunamis, storm surges, wildfire, and floods. Urban air pollution is not normally considered to be a meteorological hazard. This view has arisen because the causes of urban air pollution – industrial and motor vehicleemissions – are not meteorological in nature. Air pollution episodes, however, are sporadic in nature and their occurrence depends on a particular combination of meteorological factors. This is true even in megacities such as Mexico City, Manila, and Los Angeles that have acquired a reputation for polluted air. Analyses of air pollution episodes and hospital admissions from many countries indicate that thereis a significant increase in morbidity and mortality as a result of such episodes.Time-series studies undertaken in Sydney have shown that particulate matter, ozone and nitrogen dioxide are the pollutants that are primarily responsible for adverse health effects in that city.Air pollution, and in particular particulate matter, is believed to be responsible for just under 400 premature deaths per year in Sydney alone. This death rate is over twenty times larger than deaths due to other meteorological hazards. Part of the reason for the low death rate for the more traditional meteorological hazards is that the provision of high quality numerical weather prediction, coupled with modern communications technology, has enabled emergency service personnel to take appropriate action.Air quality forecasting systems can play an important role in mitigating the adverse effects of air pollution. The forecasts will affect the behaviour of susceptible individuals, and thus reduce adverse health effects. The outputs from forecasting systems can also be used to provide improved estimates of the total exposure to air pollutants of the inhabitants who areat risk. Such improved estimates can then be used in conjunction with longitudinal studies ofhealth effects to obtain better understanding of the complex interaction between air quality and health.  相似文献   

10.
The present work is an attempt to investigate pollution effect on an ornamental tree species Thevetia peruviana (Pers.) K. Schum. The study was conducted in various green spaces of institutional, industrial, residential and near traffic site representing as different status of air pollution concentration depending on land-use type. The resistance index calculated for selected species had mean value of 14.57 ± 0.41 observed at study sites. The dust deposition was found in range of 5.14–7.74 mg cm?2 on foliar surface of 12 cm2. The examination of leaf structure with scanning electron microscope showed presence of airborne dust particles in coarse and fine sizes with higher deposition found in industrial and residential sites. The epicuticular wax layer on upper surface of foliar was found eroded at industrial and traffic regions. The equivalent diameter of particles was observed to range from 0.45 to 12.71 µm in Poisson distributional pattern. The density of number concentration of dust particles was observed 1411 and 3703 in institutional and industrial area deposited on 0.22 mm2 of foliar surface. The elemental distribution on leaves of Thevetia peruviana has revealed a mixture of carbonaceous and soil matrix elements such as C, O, Al, Na, Si, K and Mg observed in proportion of X-rays counts per second. The whole experiment gave a positive indication for plant species as a tolerant bio-indicator of air pollutants in Delhi. The diverse flora present in city provides an opportunity for reducing harmful concentration of PM10 and PM2.5 and improving quality of air for human health.  相似文献   

11.
Biophysical and biochemical plant foliage parameters play a key role in assessing vegetation health. Those plant parameters determine the spectral reflectance and transmittance properties of vegetation; therefore, hyperspectral remote sensing, particularly imaging spectroscopy, can provide estimates of leaf and canopy chemical properties. Based on the relationship between spectral response and biochemical/biophysical properties of the leaves and canopies, the PROSPECT radiative transfer model simulates the interaction of light with leaves. In this study, more than 1100 leaf samples from the Amazon forest of Ecuador were collected at several study sites, some of which are affected by petroleum pollution, and across the vertical profile of the forest. For every sample, field spectroscopy at leaf level was conducted with a spectroradiometer. The goal of this study was to assess leaf optical properties of polluted and unpolluted rainforest canopies across the vertical profile and identify vegetation stress expressed in changes of biophysical and biochemical properties of vegetation. An ANOVA followed by Holme’s multiple comparisons of means and a principal component analysis showed that photosynthetic pigments, chlorophyll and carotenoids have significantly lower levels across the vertical profile of the forest, particularly in sites affected by petroleum pollution. On the other hand, foliar water content showed significantly higher levels in the polluted site. Those findings are symptoms of vegetation stress caused by reduced photosynthetic activity and consequently decreased transpiration and water-use efficiency of the plants. Cross-comparison between SPAD-502 chlorophyll content meter index and chlorophyll content showed strong positive correlation coefficients (r = 0.71 and r 2 = 0.51) which suggests that using the SPAD-502 chlorophyll index itself is sensitive enough to detect vegetation stress in a multispecies tropical forest. Therefore, the SPAD-502 can be used to assess chlorophyll content of vegetation across polluted and non-polluted sites at different canopy layers. The results presented in this paper contribute to the very limited literature on field spectroscopy and radiative transfer models applied to the vertical profile of the Amazon forest.  相似文献   

12.
In many arid and semiarid areas, dry lake beds (saline playa) represent a tremendous source of unconsolidated salt-rich sediments that are available for aeolian transport. Severe salt-dust storms caused by the erosion of such landforms have become very harmful natural phenomena. In this study, sample analysis and field erosion monitoring of Ebinur Lake was conducted to investigate the salt content, chemical composition, and wind erosion intensity of surface salt-rich sediments. The effects of salt-dust rising from the playa on the growth and physiological health of plants were also evaluated in this study through a leaf dustfall test. The results indicate that water-soluble salts assemble densely on the dry lake bed surface. At a depth of 0–2 cm, the highest salt contents can exceed 40%, with sulfate and chloride being the main anions present and Na+, Ca2+, and Mg2+ being the primary cations. The annual wind erosion rate ranged from 0.48 to 5.6 cm in the northwest portion of the lake and from 0.24 to 0.96 cm in the southeast portion. Salt-dust storms caused by wind erosion of saline playa sediments seriously influenced the normal absorption of minerals by plant leaves. Under the influence of salt-dust storms, plant leaves absorb more Na+, but far less K+.  相似文献   

13.
Air quality legislation is entering a transformation phase, shifting the concept of atmospheric emission control towards pollution prevention and emission minimization through a more integrated approach. This transformation, along with public pressure and increased foreign trade, is providing industries with incentives to consider their effect on the environment and to take action where required. To assist industries in determining what air pollution control technologies are best suited to power plants; an assessment of air pollution control technologies used in other countries was carried out. This assessment concluded that the best available technologies for power plants to control air emissions are electrostatic precipitators, low-NOX burners, selective catalytic reduction systems and wet flue gas desulphurization (limestone) systems. An assessment of the financial effects associated with air pollution control at power plants was conducted by completing a cost analysis. This analysis demonstrated that by increasing capital expenditure on control technologies by US$ 0.25 billion, the external costs associated with producing electricity can be reduced by almost US$ 0.5 billion. Formulation of external cost factors and the development of a software database for the information obtained from the different countries, will promote future technology selections.  相似文献   

14.
A case study is presented to assess the use of sedimentary chemical indicators for estuarine health. Reliable and efficient estuarine indicators are essential for management and monitoring purposes. Estuarine and fluvial sediments from Brisbane Water estuary were analysed for heavy metals to assess the quality of sediments and to determine the source and dispersion of contaminants in the estuary. Brisbane Water, 50 km north of Sydney, is a shallow (～5 m in main water body), wave-dominated barrier estuary with a generally sparsely developed catchment, except in the north where it is urbanised and industrialised. Heavy-metal loadings calculated for sub-catchments and the distribution of metals in surficial sediment identified Narara Creek, which drains the urbanised northern part of the catchment, as the main source of contaminants. Vertical profiles of sedimentary contaminants show that contamination continues to increase rapidly in all parts of the waterway to the present day. Concentrations of Cu, Pb and Zn in sediment adjacent to Narara Creek exceeded lower guideline levels, although moderate bioavailability (～40% for Cu, Pb and Zn) suggests the risk posed by sediments to benthic populations is low. Sediments in all parts of Brisbane Water show evidence of minor anthropogenic influence with maximum human-induced change (up to 5× enrichment) in the north of the estuary. Results demonstrate the use of sediment-bound heavy metal as an appropriate indicator of estuarine health.  相似文献   

15.
Conventional methods that assessed the mercury (Hg) levels were not only an outcome of atmospheric pollution, but also the possibility of Hg contamination from the sample collection to laboratory analyses. Our studies used the direct mercury analyzer that measured Hg rapidly and precisely at ultra-trace concentrations with detection limit of 0.0015 ng g?1 on six favored desert plants and their surrounding soil in Kuwait. Analysis revealed elevated Hg concentrations in Tamarix chinensis Lour., and Salsola imbricate Forssk., among the chosen desert plants, especially during summer than in winter, thus labeling the qualities of a bio-indicator to Hg pollution. The overall parts-wise analysis on the six selected plants showed the elevated mean Hg concentrations in the leaves (0.89 ng g?1) followed by root (0.51 ng g?1) and stem (0.39 ng g?1) in the desert plants. Reasons attribute to the capability of these plant parts to absorb, accumulate, and assimilate Hg at varying concentrations. The overall mean Hg concentration was high in soil (2.24 ng g?1) in comparison with the mean Hg concentrations in the desert plants (0.60 ng g?1) irrespective of the two seasons. Translocation and bioaccumulation factors indicated low uptake of Hg translocation in the plant parts from the soil. Furthermore, the mean Hg concentration was found high in samples collected from Governorates (GIII) in comparison with the samples collected from other Governorates indicating the effect of pollution from various sources. The present study characterizes the selected plants as bio-indicators and also validates the impact of regional and seasonal variations to Hg pollution at ultra-trace levels in the arid ecosystem.  相似文献   

16.
Twenty-seven samples of black weathering crust and host carbonates were studied from seven European countries (Germany, Hungary, Belgium, Czech Republic, France, Italy and Poland) representing 11 different sites. The samples were collected for sites for which long-term air pollution records are available. The mineralogical analyses (XRD, polarizing microscopy, SEM) have shown that despite decreasing SO2 emissions crust samples are still very rich in gypsum. Further, in all host rock samples gypsum was also detected. Good correlations (R2 > 0.9) were also found between water-soluble calcium and gypsum content and between sulphate and gypsum content both for black crusts and host rocks. The black gypsum crusts are four or five times richer in sulphate than the host rock. The conductivity of dissolved crust and host rock samples also shows a positive correlation with gypsum content of the samples. LA-ICP-MS analyses allowed the detection of high Pb-levels in black crusts and a negative shift in lead concentration at the crust/host rock transition. The lead content of the host rock is 2–5 mg/kg, while that of the crust is 3–25 mg/kg in the sample collected from Germany, while in the Belgian sample these values are 2–14 mg/kg and 80–870 mg/kg for the host rock and crust, respectively. The GC–MS technique allowed to detect the PAH content of black crusts and host rocks. The former one contains 0.6–15.6 (102.5) mg/kg, while in the host rock values between 0.2 and 2.4 mg/kg were found. The present study suggests that still large amounts of air pollution-related minerals and organic pollutants are found in the black weathering crusts of European carbonate buildings despite decreasing trends in air pollution.  相似文献   

17.
The experiments were conducted in open top chamber system installed at the University of the Punjab, Quaid-e-Azam Campus, Lahore, Pakistan. The mungbean (Vigna radiata (L.) Wilczek var.M28) seeds were sown in earthen pots and were kept in filtered air, unfiltered air and ambient air. The ozone concentration was monitored daily during 1000hrs till 1600 h. The data for light intensity and relative humidity was also regularly collected. The sets of plants growing in FA chambers (without ozone and dust particles) responded well as regards growth and yields are concerned. Unfiltered air reduced the number of nodules, their biomass and nitroginase activity in mungbean plants. The present study documents that the species of mycorrhizal fungi sensitive to tropospheric ozone failed to reproduce in ambient air and unfiltered air chambers (without dust particles). Out of a total of 24 species, eighteen species belonged to the genus Glomus, two each to Sclerocystis, to Acaulospora and one each to Gigaspora and Scutellospora. The total number of species was variable during the growth phase. The total number of species reduced in soil of UFA chambers with the passage of time. Species richness reduced to almost half in UFA plants as compared to FA plants. Species of the Genus Glomus were highly abundant species at various harvests in all air treatments. Amongst most abundantly recovered Glomus species were G. fasciculatum, G. mosseae, G. aggregatum, G. caledonicum, G. deserticola, G. geosporum, and G. monosporum. The pattern of abundance kept on varying at various harvests for different air and mycorrhizal treatments. In the case of plants of UFA treatment, only two species of Glomus were abundant namely G. fasciculatum and G. geosporum. Species of Acaulospora and Gigaspora in particular and Scutellospora and Sclerocystis in general were sensitive to polluted air.  相似文献   

18.
Human activities contribute different pollutants to receiving waters, often with significant variations in time and space. Therefore, integrating multiple parameters of water quality and their spatiotemporal variations is necessary to identify the pollution characteristics. Based on the water quality monitoring data with 12 parameters for 2 years at 22 sampling sites in the Cao-E River system, eastern China, the projection pursuit method was used to project all parameters and their temporal variations into a one-dimensional vector through two projections. Accordingly, we could easily assess the comprehensive water quality in different sampling sites and then classify their water pollution features. Factor analysis was then used to identify the pollution characteristics and potential sources. Results showed that all sampling sites for the river system could be classified into four groups: headwater sites (HS), agricultural nonpoint sources pollution sites (ANPS), point sources pollution sites (PSPS), and mixed sources pollution sites. Water quality in HS was good, containing only a few nutrients from the woodland runoff and soil erosion. For ANPS, the main pollutants were dissolved phosphorus, total P, and nitrate nitrogen (NO3 ?-N), mainly from farming land. For PSPS, ammonium nitrogen (NH4 +-N) and organic pollutants originated from industrial and municipal sewage. In HS and ANPS, NO3 ?-N was the main form of nitrogen, and a high ratio of NO3 ?-N/NH4 +-N was a remarkable characteristic, whereas NH4 +-N was the main form of nitrogen in PSPS. Except in HS, water quality in the other groups could not meet the local water quality control standard. Finally, suggestions were proposed for water pollution control for the different groups.  相似文献   

19.
The Kathmandu valley urban area is growing as a metropolis. Bishnumati corridor in Kathmandu valley is is a target of increased pollution. The unabated solid waste land-filling on either side of the river-bank and animal slaughter houses and biological waste arising from these activities, busy commercial and high residential density characterize the corridor. Six areas, namely Teku Dovan, Kalimati Bridge, Kankeswori, Shova Bhagwati, Balaju and New Bus Park areas, all areas falling within the Bishnumati corridor were selected to measure air quality representing corridor. The pollutants quantified were respirable particulate matter — PM10, sulphur dioxide and oxides of nitrogen. The air-borne microbial flora and fungi load quantification were also carried out. Teku Dovan (918.92 μg/m3) and Shovabhagavati areas (847.45 μg/m3) showed higher levels of particulates. Kankeswori area showed highest levels of aerial bacterial (3.7×107 cfu/m3) and fungal load (4.8×108 cfu/m3). The PM10 levels at all the sites are substantial and fall in the categories of ’Harmful’ and ’Hazardous’ quality of air suggesting that the corridor needing intervention to minimize the risk from air pollution. Non-judicious open-air combustion of the solid waste contributes to air pollution. Heavy traffic and few roads not clad with asphalt; perceivable mal-odor and persistent stench emanating from the indiscriminate disposal and consequent putrefaction processes, dense population and increased commercial activities are other principal contributing sources to the resulting pollution of the corridor. In view of this status, mitigating measures to minimize exposure to the toxicants in the corridor is a necessity.  相似文献   

20.
美国全球变化研究计划实施进展与研究展望   总被引：1，自引：2，他引：1  
美国全球变化研究计划（USGCRP）自成立以来的10年中，取得了丰硕的研究成果，也面临新的挑战，列举了自1990年以来尤其是近几年来USGCRP的主要成果与贡献，其中在国家评估，厄尔尼诺－南方涛动的预测，全球温度记录，过去1000年中最温暖的时期，北美碳汇，温室气体增加与臭氧损耗，臭氧损耗评估，大气污染物的长距离输送，海洋分析，热带测雨卫星，雷达卫星，火灾监测，SeaWiFS，全球环境维息服务等方面取得的成绩尤为显著，剖析了USGCRP在未来10年中的研究目标及其研究重点和面临的挑战。  相似文献   

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