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1.
A methodology to determine economically the spatial concentration distribution of the air pollutants of carbon monoxide (CO), sulphur dioxide (SO2), nitrogen monoxide (NO), nitrogen dioxide (NO2), oxides of nitrogen (NOx) and traffic rates (TR) is described. It involves the immediate transfer of samples from field to analysers for measurement and a subsequent statistical treatment. The proposed methodology has been applied in Patras using 5 and 50-l Teflon air sample bags, sampling at least 12 to 36-l actual volumes within a 20-min time interval. Totally, 221 pairs of 5-l and 112 single 50-l samples were randomly picked in morning rush hours of working days from 64 locations of a 40.0-km2 area during a winter period, when peaks of primary air pollutants usually occur due to high traffic rates and systematic inversions. Measurements were used to statistically calculate spatial average levels approximating 1-h mean concentrations with acceptable mean probable errors less than 25 % for indicative random sampling. The 1-h levels were strongly correlated to the corresponding traffic rates. Iso-concentration diagrams indicated possible zones susceptible to high pollution levels and helped to check the location appropriateness of the existing monitoring stations for (a) fixed urban-background measurements at the Vas. Georgiou A’ Sq., which was ideal, and (b) fixed traffic-oriented measurements, which should be relocated to the Ipsilon Alonion Sq. In addition, data helped to determine other points where indicative measurements should be performed. Data could be very useful for the Patras air quality assessment in conjunction with model predictions and/or objective estimation methods.  相似文献   

2.
Nitrogenous air pollutants including nitrogen dioxide (NO2), nitric acid (HNO3), nitrate (NO 3 ? ), ammonia (NH3), ammonium (NH 4 + ), and nitrous acid (HONO) were characterized at an urban forested (UF) site in Hiroshima and at a suburban forested (SF) site in Fukuoka, western Japan, using an annular denuder system for 1?year from May 2006 to May 2007 to compare the concentrations and chemical species of atmospheric nitrogenous pollutants between UF and SF sites. The proximity of the urban area was reflected in higher NO2 concentrations at the UF site than at the SF site. NO2 was more oxidized at the SF site because it is farther from an urban area than the UF site, which was reflected in higher concentrations of HNO3 at the SF site than the UF site. HNO3 and acidic sulfate is neutralized by NH3, existing as ammonium nitrate (NH4NO3) and ammonium sulfate [(NH4)2SO4] at the UF site. At the SF site, acidic sulfate is neutralized by NH3, existing as (NH4)2SO4, but NH4NO3, had scarcely formed at the SF site. A much higher HONO concentration was observed at the UF site than at the SF site, especially in winter and spring at night, which could be explained by higher NO2 concentrations at the UF site because of its proximity to an urban area and stagnant meteorological conditions. Atmospheric HONO determination was critical in evaluating the possibility of damage to trees in UF areas.  相似文献   

3.
The tall, aerodynamically rough surfaces of forests provide for the efficient exchange of heat and momentum between terrestrial surfaces and the atmosphere. The same properties of forests also provide for large potential rates of deposition of pollutant gases, aerosols and cloud droplets. For some reactive pollutant gases, including SO2, HNO3 and NH3, rates of deposition may be large and substantially larger than onto shorter vegetation and is the cause of the so called "filtering effect" of forest canopies. Pollutant inputs to moorland and forest have been compared using measured ambient concentrations from an unpolluted site in southern Scotland and a more polluted site in south eastern Germany. The inputs of S and N to forest at the Scottish site exceed moorland by 16% and 31% respectively with inputs of 7.3 kg S ha-1 y and 10.6 kg N ha-1 y-1. At the continental site inputs to the forest were 43% and 48% larger than over moorland for S and N deposition with totals of 53.6 kg S ha-1 y-1 and 69.5 kg N ha-1 y-1 respectively. The inputs of acidity to global forests show that in 1985 most of the areas receiving > 1 kg H+ ha-1 y-1 as S are in the temperate latitudes, with 8% of total global forest exceeding this threshold. By 2050, 17% of global forest will be receiving > 1 kg H-1 ha-1 as S and most of the increase is in tropical and sub-tropical countries. Forests throughout the world are also exposed to elevated concentrations of ozone. Taking 60 ppb O3 as a concentration likely to be phytotoxic to sensitive forest species, a global model has been used to simulate the global exposure of forests to potentially phytotoxic O3 concentrations for the years 1860, 1950, 1970, 1990 and 2100. The model shows no exposure to concentrations in excess of 60 ppb in 1860, and of the 6% of global forest exposed to concentrations > 60 ppb in 1950, 75% were in temperate latitudes and 25% in the tropics. By 1990 24% of global forest is exposed to O3 concentrates > 60 ppb, and this increases to almost 50% of global forest by 2100. While the uncertainty in the future pollution climate of global forest is considerable, the likely impact of O3 and acid deposition is even more difficult to assess because of interactions between these pollutants and substantial changes in ambient CO2 concentration, N deposition and climate over the same period, but the effects are unlikely to be beneficial overall.  相似文献   

4.
土地利用变化与城市空气环境效应的关系   总被引:1,自引:0,他引:1  
大规模的城市用地开发导致对各种自然过程和生态过程的改变,产生了复杂的生态环境后果.该文以成都市为例.基于遥感与GIS技术,提取、分析城市土地利用变化信息;选择影响成都市空气环境质量NO2和总悬浮微粒物浓度等指标的采样点数据,通过空间分析、叠加城市土地利用图层.对获取土地利用的城市空气环境效应进行了研究.结果表明:1992-2008年研究区土地利用时空变化显著,土地利用变化以耕地的大幅度减少和建设用地和林地显著增加为主要特征;土地利用对城市空气环境产生显著影响.林地对NO2各浓度变化影响明显,各浓度所占的土地利用面积为最大;城镇用地对总悬浮微粒物的最高一级浓度影响显著,所占土地利用面积最大;NO2和总悬浮微粒物浓度的空间分布由研究区的青白江区-新都区-中心城区等区域一线向两侧依次降低,与城镇用地、工矿与交通用地的空间分布基本一致.因此,这一研究结果对改善城市空气环境质量、促进城市可持续发展和制定科学应对决策具有积极意义.  相似文献   

5.
Understanding and controlling air pollution in highly populated areas is very important, although interpreting the levels of gaseous pollutants and airborne particulate matter is complicated by dominant natural and anthropogenic emissions, micro-meteorological processes, and chemical reactions which take place directly in the atmosphere. For this reason, it is very difficult to relate the characteristics of air pollution to one or more specific emission sources. The aim of this paper is to detect associations among elements and organic compounds emitted from specific sources by means of chemical analyses, statistical processing of data, seasonal evolution study, and geochemical considerations to trace their origin. A detailed characterization of air quality during the period September 2000–September 2001 was carried out in three locations of the Venice region: A heavy traffic urban site, a public park, and the island centre of the city of Venice. Twenty-eight inorganic elements, four polycyclic aromatic hydrocarbons, CO and benzene were quantified and processed by a statistical procedure based on factor analysis considering variations on a seasonal basis. Results show the presence of associations between elements and compounds with the same behaviour in all sampling points. This indicates that several pollutants originate from a common source, and are then “diluted” throughout the study area, maintaining the imprint of their origin. Pt, polycyclic aromatic hydrocarbons, CO and benzene originating from the exhaust gas of vehicles are all linked in the traffic factor, whereas Cd is associated with Se, having a common source in industrial processes.  相似文献   

6.
采用数字显微系统测定了部分华南地区土壤中粘土颗粒粒径分布分形维数值,提出了土壤中粘土颗粒群粒度分布分形维数的几何法计算模型,并就这种分形维数与土壤比表面积和土壤透气性等性质的相互关系作了初步探讨。结果表明,采用数字显微系统测定的粘土颗粒粒径分布分形维数值介于2.2708到2.9483之间,与常规方法测定结果吻合;含砂较多的土壤样品,BET比表面积和Blaine透气时间随粒度分布分形维数值增大而减小;含粘粒较多的土壤样品,BET比表面积和Blaine透气时间同随粒度分布分形维数值增大而增大。  相似文献   

7.
土壤中有机污染物的老化及其环境意义   总被引:1,自引:0,他引:1  
李久海  潘根兴 《土壤通报》2006,37(2):378-382
持久性有机污染物随着在土壤中时间的延长,其生物有效性和毒性会逐渐下降的现象被称为老化。老化对有机污染物的有效性和行为归趋有着重要的影响。本文对国外有关老化对有机污染物生物有效性和可浸提性的影响,老化的机理和影响因素,以及老化后有机污染物生物有效性评价方法的研究作了概述。指出老化作为土壤对有机污染物修复的一种自然修复过程,可降低有机污染物的潜在环境风险,具有重要的环境意义。  相似文献   

8.
Acid rain at a rural site in Chongwon (KHN), central Korea has been under observation since 1990. To substantiate the 10-year observations, rain samples from six other sites were also collected and analyzed. Results show that acid rain occurred frequently at all sites. At KHN, seasonal and annual variability of pH values had a 10-year VWM value of 4.67 and an arithmetic mean value of 5.09. In general, a high value of pH occurred during springtime when the occurrence of yellow sand (dust) was prevalent in East Asia; during summer, heavy rain usually contained neutral pH values. During other seasons, the degree of acidic precipitation usually coincided with certain air flows. Most frequently, air flows and cyclones coming from south and central China often resulted in precipitation with low pH values observed in Korea. Using daily satellite observations from 1996, we have also been monitoring the long-range and large-scale transport of air pollutants (LSTAP) over East Asia. Many samples of LSTAP were obtained when they were crossing the Yellow Sea and moving over the Korean Peninsula and to SW Japan. The width of the Yellow Sea is ca. 350~700 km and air pollutants take 1~2 days to cross it. Cases of acid rain in Korea clearly correlate wth the LSTAP from source regions in China.  相似文献   

9.
In order to address the problem of pollutant effects on trees against the background of environmental fluctuations a simulation model using radial increment as an indicator of tree productivity is proposed. Ring times series of large trees provide one of the most acceptable biological indicators for the assessment of pollutant impact. This research focused on the tallest severely damaged and healthy trees growing close to each other in the surroundings of Jonava Mineral Fertilizer plant, which primarily emits nitrogen (N) and sulphur (S) compounds. The annual increment was found to be strongly correlated with mean September air temperature of the previous year and S load. The correlation coefficient (k=0.961) between modelled and observed tree ring times series of severely damaged trees proves the impact of S load on growth and vitality of a tree and enables fulfillment of tree condition prognosis.  相似文献   

10.
土壤污染物源解析方法及其应用研究进展   总被引:10,自引:2,他引:10       下载免费PDF全文
张长波  骆永明  吴龙华 《土壤》2007,39(2):190-195
本文介绍了污染物源解析的方法体系,重点对化学质量平衡法、多元统计模型、混合方法、分子标志物与同位素技术等受体模型研究方法的原理与应用进展加以总结,论述了化学质量平衡法和多元统计模型的优缺点、适用范围及应用现状;指出以这两种方法为基础形成的混合方法可避免前者选择排放源种类时的主观性,同时又可检验后者在鉴别过程中是否遗漏其他未知源,从而能够发挥最大的优势;最后对源解析方法的发展趋势及土壤学应用加以展望。  相似文献   

11.
Many bryophytes rely to a large extent on atmospheric deposition for their nutrient uptake.However, increasing levels of atmospheric ammonium NH 4 + and nitrate NO 3 - attract concern as to the possible harmful effects onbryophytes from these two nutrient sources. Changes in nitrate reductase (NR) activities, cation(Ca, K and Mg), total nitrogen (N) and organic acid concentrations were investigated for themosses, Racomitrium lanuginosum, Rytidiadelphus loreus and Philonotis fontana, in response to asingle field misting with 3 mol m-3 NH 4 + and NO 3 - . Increases of 20% were recordedfor tissue N content, 48 hr after misting with N containing solutions. When labelled NH 4 + or NO 3 - were applied to R. Lanuginosum at 1, 3 and 6mol m-3 concentrations, partitioning ofincorporated 15N between different tissueregions occured, with the highest N uptake in the upper stem and leaves. High concentrations ofapplied N resulted in reduced efficiency of N uptake. NH 4 + applications caused declines in NR activities, organic acidsand cations, whereas, NO 3 - treatments causedthe reverse response. Changes in cation contents, organic acids and NR activity reflect short-termregulation of N metabolism in the presence of defined N sources, as well as potential mechanismsof regulating cell pH homoeostasis. The consistency of physiological responses, especially NRactivities, over short-term pollution episodes, provides evidence for their use as indicators of both NH 4 + and NO 3 - pollution.  相似文献   

12.
对北京地区具代表性的环境功能区表层土壤饱和烃的组成与分布特征进行分析,并讨论了饱和烃污染物的来源。研究结果表明,在不同环境功能区表层土壤样品中均检测到了正构烷烃、类异戊间二烯烷烃、烷基环己烷和甾、萜烷烃等饱和烃化合物,其中正构烷烃和类异戊间二烯烷烃占优势。不同环境功能区和土壤类型的表层土壤样品中饱和烃的组成、分布特征和来源均存在明显差异,其中城区土壤受人为污染最为严重。表层土中饱和烃类化合物的来源比较复杂,既有人为污染源,又有天然来源。其中,中-低碳数正构烷烃主要是人为来源,高碳数正构烷烃主要为生物来源;类异戊间二烯烷烃、烷基环己烷和甾、萜类化合物则主要来源于矿物油、化石燃料和生物质不完全燃烧的产物等。  相似文献   

13.
空气负离子是衡量一个地区空气清洁度的重要指标,对人体的心理和生理机能具有重要的促进作用。随着森林生态旅游的兴起,空气负离子的发生过程及影响机制已成为生物气象、森林生态和森林康养等相关领域的研究热点。本研究以华北低丘山地栓皮栎人工林为试验对象,在2018年和2019年6−9月森林植被叶面积相对不变期间,定位观测获取人工林冠层空气负离子及微气象参数,采用Python软件筛选出光合有效辐射约为零,温度、风速及颗粒物浓度相对不变条件下的观测数据,分析空气湿度(RH)对空气负离子浓度(NAI)的影响特征,建立基于空气相对湿度的预测模型,并对模型进行检验。结果表明,在不同空气相对湿度范围内,空气负离子浓度随空气湿度的升高呈现三种变化趋势,在空气相对湿度35%~55%范围内,空气负离子浓度相对稳定,二者呈稳定常数关系;在相对湿度55%~75%范围内,空气负离子浓度迅速上升,二者呈线性递增关系;在相对湿度75%~95%范围内,空气负离子浓度适度下降,二者呈线性递减关系。在此基础上,构建了空气负离子浓度与空气相对湿度的分段拟合方程,3个湿度区间分别为NAI=729;NAI=9.396RH+198.994,决定系数(R2)为0.807(P<0.01);以及NAI=−4.849RH+1232.992,决定系数(R2)为0.642(P<0.01)。各拟合函数的预测值与实测值均不存在显著差异,均方根误差(RMSE)分别为6.175、7.091、8.213,而RH在55%~75%和75%~95%范围内决定系数(R2)分别为0.806、0.836,模型的模拟精度高且均方根误差较小。说明构建的分段拟合函数能够准确反映空气相对湿度对空气负离子浓度的影响,可为进一步深入研究空气负离子对气候变化的响应机制提供基础依据。  相似文献   

14.
The presence of illicit drugs and their metabolites in surface waters has to be considered a new type of hazard, still unknown, for the aquatic ecosystem, due to the potent pharmacological activities of all the illicit drugs. Our research was therefore aimed at evaluating the impact of illicit drugs on the aquatic fauna, till now still undervalued. To this aim, we verified the ability of the European eel (Anguilla anguilla), a well-known biomonitor of environmental contamination, to bioaccumulate cocaine, one of the most abundant illicit drugs found in surface waters. Silver eels were exposed to a nominal cocaine concentration of 20?ng/l for 1?month; at the same time, control, carrier, and post-exposure recovery groups were made. Brains, gills, liver, kidney, muscle, gonads, spleen, digestive tract, and sections of dorsal skin were assayed by high-pressure liquid chromatography. Cocaine was found in the tissues of the treated eels and, at low concentrations, in almost all tissues of post-exposure recovery eels. These results indicate that cocaine is able to accumulate into the eel tissues; its presence suggests potential risks for eels since cocaine could affect their physiology and contribute to their decline, and for humans consuming contaminated fish.  相似文献   

15.
Multivariate methods were used to relate microcrustacean (pelagic and littoral) richness and composition (presence/absence) to water quality and other environmental variables. All acidification variables (pH, aluminium, ANC) showed significant correlation with both species richness and composition. The variation in microcrustacean richness was best explained by the combination of dissolved organic carbon (DOC), fish species richness and lake area. Of 16 variables tested, pH showed strongest correlation with the main gradient in the crustacean composition explaining between 13 and 16% of the variance in the species data (CCA). pH, elevation, lake area, average depth, DOC, conductivity and fish species richness explained 30–54% of the total variance. Stronger correlation was obtained between species composition and environmental data in analyses which included the between-year differences than analyses based on the cumulative species records. Analyses based on the pelagic species exclusively gave similarly stronger correlation than analyses based on all crustacean species. Small changes in the species composition during the three years of study may be an indication of recovery of microcrustaceans in Killarney lakes.  相似文献   

16.
系统地归纳了近几年来对辽宁省喀左县农作物主要害虫发生发展与气象条件关系及其预测模型的研究成果;对2002年农作物主要害虫发生趋势进行了预报;并提出若干防治对策。  相似文献   

17.
Spheroidal carbonaceous particles (SCPs) from the sediments of 48 Irish lakes were enumerated and characterised according to fuel type. The concentration of metals was determined in the surface sediments and in selected mosses from the catchments of these lakes. Generally the metal concentrations in both the surface sediments and mosses were consistent with background levels found in the remote parts of Europe. Where higher metal concentrations occurred these could often be accounted for by local geochemical sources. SCP levels in the sediments of the selected lakes along the east coast were of sufficient magnitude to suggest a transboundary influence notwithstanding local sources. SCP characterisation also suggests the influence of emissions in Northern Ireland on deposition, particularly in the north-west of Ireland. There was reasonable correlation between the concentration of oil particles in the surface sediments and vanadium, but not with nickel, in mosses. SCP concentrations were not correlated with measured physical characteristics of the lakes. The level of deposition indicated is not likely to have a significant impact on human health over and above the damaging effects of urban dwelling but the adverse impact of this deposition on acid-sensitive surface waters in Ireland has been recorded.  相似文献   

18.
Rose  N.L.  Harlock  S. 《Water, air, and soil pollution》1998,106(3-4):287-308
Spheroidal carbonaceous particles (SCP) and trace metals (Cd, Cu, Pb, Ni, V and Zn) were analysed from 75 lake surface sediments across the UK. Trace metals were additionally analysed from catchment mosses (Hylocomium splendens and Pleurozium schreberi) from 43 of the sites but were absent from the remainder. Spatial distribution of SCP concentration and trace metal concentrations in sediments and mosses showed good agreement with each other and with known emission sources. Particles were allocated to their fuel-type and spatial trends in these data showed good agreement with potential sources. High areas of oil particle deposition were identified in the south-east of England, Merseyside, Galloway / Northern Ireland, the Firth of Forth and eastern Scotland. Oil SCP concentrations showed good agreement with Ni and V concentrations in mosses suggesting an atmospheric source for these metals from the combustion of this fuel. Characterised SCP trends also showed good agreement with predictions from models such as HARM and EMEP. Most high deposition areas of metals and particles were found to coincide with population centres suggesting a possible impact on human health.  相似文献   

19.
大庆龙凤湿地土壤理化性质与硒元素分布关系研究   总被引:5,自引:0,他引:5  
为了解大庆龙凤湿地土壤理化性质对硒的含量、形态与分布的影响,对大庆龙凤湿地保护区4个样区20个样点4个不同层次土样中硒的含量、形态、分布以及部分理化性质进行了研究。结果表明:大庆龙凤湿地土壤全硒含量为121~150μg/kg,由于硒淋溶流失的影响,随土壤深度的增加,全硒含量无明显变化;有效硒总量为22~28μg/kg,包括水溶态硒、交换态硒与富啡酸态硒三种形态。影响土壤硒的主要因素包括土壤有机质、土壤黏粒含量及pH值,其中土壤有机质、黏粒含量与硒含量之间存在正相关关系,土壤pH值与硒含量存在极显著的负相关关系。  相似文献   

20.
The concentrations of fly-ash particles were studied in the surface sediments of 42 lakes in Estonia. Concentrations of both spheroidal carbonaceous particles (SCPs) and inorganic ash spheres (IASs) were determined and the particles chemically characterised to different fuel types. This was accompanied by trace metal analyses from lake surface sediments and catchment mosses in order to determine the distribution of atmospheric pollutants. The obtained spatial distribution data for fly-ash particles varied to a great extent, partly due to differences in sedimentation rates but mainly due to higher deposition in industrial areas. The distribution patterns of the different particle types in lake sediments, as well as the trace metals in mosses, show that the deposition of airborne particulates is of local origin around pollution sources and that the share of long-range transported atmospheric impurities is high along the main cyclonic routes in Estonia.  相似文献   

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