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1.
采用"二重源解析"技术解析了太原市的各单一源类对城市道路尘(以下简称道路尘)的贡献值和分担率;各单一源类和道路尘对城市扬尘的贡献值和分担率;同时解析了各单一源类、道路尘和城市扬尘对环境空气颗粒物的贡献值和分担率。各源类对PM10的贡献率分别是:城市扬尘,27%;道路尘,20%;土壤风沙尘,10%;煤烟尘,13%;建筑水泥尘,10%;机动车尾气尘,11%;钢铁尘,1%;其他,8%。  相似文献   

2.
基于长沙市10种典型植物叶片的多个滞尘指标,运用模糊数学理论构建植物的滞尘等级与识别模型,实现绿化植物滞尘综合量化评判方法的探究.首先,常规方法采集叶样后,运用打孔称质量法测量叶表面积参数,显微观察法计算植物叶表气孔与绒毛密度,干洗法测量单位叶面积最大滞尘量与自然滞尘量.然后,运用模糊聚类理论对10种植物滞尘指标进行滞...  相似文献   

3.
城市绿地滞尘作用机理和规律的研究进展   总被引:7,自引:0,他引:7  
城市绿地的滞尘作用是城市绿地重要的生态功能之一。综述了城市绿地的滞尘机理、变化规律。城市绿地的滞尘机理主要分为3种方式:滞留、附着和粘附;城市绿地滞尘能力与滞尘时间、城市环境、植物种、植物群落结构等因素存在密切的联系。不同植物滞尘能力的差异很大,总体规律表现为乔木植物〉灌木植物〉草本植物;但就单位叶面积来说,滞尘能力均以草本植物〉灌木植物〉乔木植物〉藤本植物;主要原因是垂直高度不同,灌草能有效截留地面的扬尘(城市中灰尘的主要来源)。研究表明,同种类植物种在封闭式环境条件下叶片滞尘量明显低于开敞式环境条件下的滞尘量,因此,在城市不同环境中的植物滞尘能力表现为工业区〉商业交通区〉居住区〉清洁区。随着季节和滞尘时间的变化,每种植物都存在一个滞尘限度,如果无雨水或人为干扰,最终达到一个动态平衡。从城市绿地群落的垂直结构看,乔—灌—草型的绿地具有相对较好的滞尘作用,是目前较为理想的绿地类型;另外,在城市绿地面积明显不足的情况下,以藤本植物为主的垂直绿化将成为城市绿化发展的新方向。同时,在城市绿地滞尘机理、规律以及植物滞尘能力评价等方面仍需要进一步深入研究。  相似文献   

4.
针对目前对于一般尘源控制研究较少,而系统研究粉尘的扬尘(尘化)机理的研究就更少这一状况,提出弄清尘化机理、从源头上控制是治理粉尘的首要问题,对粉尘颗粒作用力进行分析,特别就超细粉尘的扬尘机理提出相应的物理模型并进行初步研究.图1,参2.  相似文献   

5.
● Compositional patterns of PAHs in dust aerosol vary from soil during dust generation. ● The EF of PAH in dust aerosol is affected by soil texture and soil PAH concentration. ● The sizes of dust aerosol play an important role in the enrichment of HMW-PAHs. Polycyclic aromatic hydrocarbons (PAHs) are major organic pollutants in soil. It is known that they are released to the atmosphere by wind via dust aerosol generation. However, it remains unclear how these pollutants are transferred through the air/soil interface. In this study, dust aerosols were generated in the laboratory using soils (sandy loam and loam) with various physicochemical properties. The PAH concentrations of these soils and their generated dust aerosol were measured, showing that the enrichment factors (EFs) of PAHs were affected by soil texture, PAH contamination level, molecular weight of PAH species and aerosol sizes. The PAHs with higher EFs (6.24–123.35 in dust PM2.5; 7.02–47.65 in dust PM10) usually had high molecular weights with more than four aromatic rings. In addition, the positive correlation between EFs of PAHs and the total OCaerosol content of dust aerosol in different particle sizes was also statistically significant (r = 0.440, P < 0.05). This work provides insights into the relationship between atmospheric PAHs and the contaminated soils and the transfer process of PAHs through the soil-air interface.  相似文献   

6.
The miners as well as the inhabitants vicinity to the mining areas are generally susceptible to the respiratory disorders due to constant exposure to the coalmine dust for a prolonged period. In this paper the dust concentration and dust dose associated with the rate of tuberculosis around the major part of Ib Valley Coalfield (Belpahar and Brajarajnagar area) have been analysed. Several field trips around Ib Valley Coalfield have been conducted for consecutively three years (2005, 2006 and 2007) to evaluate the present status of the dust concentration and rate of tuberculosis infection. It was observed that the dust concentrations of different residential places as well as the places vicinity to the opencast mining projects have been increased in the subsequent years of investigation. As a result, the dust doses of various residential places have also increased in a parallel manner. The dust doses of various mining sites range from 25.51 to 37.08 mg, 34.76 to 41.03 mg and 37.8 to 44.49 mg during 2005, 2006 and 2007 respectively. Interestingly in most of the mining sites the dust doses are more than the safe dust does (32 mg). An attempt has been made to correlate the dust concentration with tuberculosis infection in the area by making a questionnaire survey. Early symptoms of tuberculosis were reported in case of 121 out of 205, 129 out of 212 and 145 out of 220 inhabitants during 2005, 2006 and 2007 respectively. The study clearly revealed that the tuberculosis patients have been increased significantly in the successive years of investigation.  相似文献   

7.
Phthalic acid esters (PAEs) are widely used as plasticizers and in consumer products, which may enter the environment and present risks to human health. U.S. EPA classifies six PAEs as priority pollutants, which could be accumulated in street dust at the interface of atmosphere, biosphere and geosphere. This study collected a total of 58 street dust samples from Xi’an City in Northwest China and analyzed for concentrations of the priority PAEs. Composition, distribution, sources and health risk of the PAEs were further examined. All the priority PAEs were detected in the street dust. The concentrations of individual PAEs varied between not detected and 183.19 mg/kg. The sum of the 6 priority PAEs (∑6PAEs) ranged from 0.87 to 250.30 mg/kg with a mean of 40.48 mg/kg. The most abundant PAEs in the street dust were di-n-butyl phthalate and di (2-ethylhexyl) phthalate (DEHP). Higher concentrations of ∑6PAEs in the street dust were found in the south and west parts of Xi’an City as well as its urban center, which were possibly attributed to the prevailing northerly Asian winter monsoon. The PAEs in the street dust originated mainly from wide application of plasticizers as well as cosmetics and personal care products. The main pathways of human exposure to PAEs in the street dust were ingestion and dermal adsorption of dust particles. The non-cancer risk of human exposure to PAEs in the street dust was relatively low, while the risk to children was higher than that to adults. The cancer risk of human exposure to DEHP in the street dust was lower than the standard limit value of 10?6.  相似文献   

8.
中国北方典型污染城市主要绿化树种的滞尘效应(英文)   总被引:1,自引:0,他引:1  
为研究城市人工植被的滞尘效应及其对城市生态环境的改善作用,以中国北方典型污染城市--临汾市为例.通过野外典型采样法和室内分析,测定了不同生活型主要绿化植物的滞尘能力,讨论了植物的滞尘量与滞尘时间的关系,并且研究了污染程度及距污染源距离对植物滞尘能力的影响.结果表明,在同一降尘条件下,不同生活型植物滞尘能力差异表现为草本植物的滞尘能力显著高于其它生活型植物(落叶乔木,灌木和藤本植物),而其它生活型植物间的滞尘能力无显著差异性;对针叶林来说,圆柏和雪松的滞尘能力间亦存在显著差异.在不同的污染情况下(污染程度及和污染源的距离不同),同种植物的滞尘能力亦有明显的差异,这与植物的高度和生长特性有关.而且,随时间推移,植物叶片的滞尘量呈现周期变化.而不是一个随时间无限增长的量,也有其饱和量.因此,在进行城市绿化设计时,需要综合考虑绿化树种的滞尘能力、滞尘周期及其生长环境情况等.  相似文献   

9.
王明仕  李晗  王明娅  曹宁  宋党育 《生态环境》2014,(12):1933-1937
为了研究中国大气降尘量的地域性分布特征,探讨大气降尘的影响因素,文章以中国大气降尘研究为基础,汇总近20年25个行政区44个地区的降尘量数据,以10 t·km-2·month-1为间隔首次划分降尘区间,为中国降尘量标准的制定提供参考。中国大气降尘现有研究多集中在东北部、中东部地区以及西北沙漠地区,降尘量整体分布为北方高于南方,西部多于东部。除涉及强沙尘暴袭击区域外,现有研究区域的降尘量算术平均值为14.73 t·km-2·month-1,53.7%的研究区域降尘量小于该平均值。降尘量少于20 t·km-2·month-1的地区多集中于沿海地区、长江中下游地区以及东北平原地区,此类地区多为旅游景区和重要的商品粮产地,植被覆盖率较高,水土保持性能良好,且不易有较大的风沙侵袭;华北平原地区、内蒙古高原地区和准噶尔盆地一带降尘量相对偏高,此类区域多为重工业区,发展经济的同时造成了不同程度的环境污染和资源掠夺;降尘量最大的地区位于塔里木盆地一带,最大值为2915.96 t·km-2·month-1,属于沙尘暴多发区。大气降尘量虽会在一定程度上受到经济发展、工业布局、能源结构的影响,但更多的是因为其地域性差异而造成降尘量不同。中国现有的各地降尘量的数据较少,且研究区多位于城市等人类活动中心,更多地区的降尘量尚需要进一步研究。  相似文献   

10.
石家庄大叶黄杨叶片滞尘量及滞尘颗粒物的粒度   总被引:5,自引:0,他引:5  
大叶黄杨强滞尘能力是城市近地面层环境中清除颗粒物污染的重要机制。以大气颗粒物污染严重的石家庄市为代表,选取石家庄裕华路北部市区为研究范围,对大叶黄杨叶片的滞尘效应及滞尘颗粒物粒度特征进行了研究。结果表明,在晴朗或多云微风天气条件下,30个取样点的大叶黄杨叶片平均滞尘量为0.356g/(m2.d),颗粒物的平均粒度值为1.91μm。大叶黄杨叶片滞尘量在石家庄市不同地区的差异排序为:北二环地区>体育大街与东二环地区>中华大街与西二环地区>西郊>东郊>火车站附近地区>博物馆周边地区。因此,石家庄市大气环境治理应针对不同地段的污染情况采取不同的治理方法。  相似文献   

11.
The objective of this study was to determine the dust concentrations in selected tractor and combine operations in eastern Mediterranean region in Turkey Mean dust concentrations were 137.9 mg m(-3), 83.6 mg m(-3), 80.3 mg m(-3), and 88.8 mg m(-3) respectively for soil packing, furrowing, straw making, and baling on tractors with no cabins whereas 106.9 mg m(-3) was found in combines without cabins, which are much higher than the limit dust concentration (10 mg m(-3)) considered hazardous for workers' health. In tractor operations with field-installed cabins, mean dust concentrations were 5.6 mg m(-3), 6.6 mg m(-3), 6.4 mg m(-3), and 3.7 mg m(-3), respectively in soil packing, furrowing, straw making, and baling while 4.7 mg m(-3) was measured in combines with field-installed cabins. Considering unit-manufactured cabins, mean dust concentrations were 1.1 mg m(-3), 1.6 mg m(-3), 3.2 mg m(-3), and 1.4 mg m(-3) respectively in tractor operations, and 1.4 mg mr(-3) in combine operations. Variance analyses showed that not only the respiration environment of the workers but also the field operation had a significant effect on measured dust concentrations (p < 0.01). Pearson correlation coefficient was 0.74 (very strong level) between dust concentration and wind speed in soil packing, 0.46 (medium level) between dust concentration and wind speed in baling, and 0.44 (medium level) between dust concentration and ground speed in combining.  相似文献   

12.
Little information on the evaluation of airborne particulate matter (APM) and sedimentation particles from subway stations is available. The thermal metamorphism of train wheels generating toxic particles in subway stations is a possibility. In this study, the toxicity and physiological effects of particles from subway stations were evaluated using a yeast bioassay system. Estrogenic and antiestrogenic activities of APM in APM extracts from subway stations were determined. No estrogenic activity was found in the APM fractions and their S9-activated APM samples. Sedimentation dust samples also showed no estrogen activity. In contrast, extracts from sedimentation dust samples showed antiestrogen activity. Marked yeast toxicity was observed in the samples extracted from sedimentation dust. Potent yeast toxicity was also found in the S9-activated extracts from sedimentation dust. The results suggest that sedimentation dust from a semiclosed area of a subway system has antiestrogen activity, although both the origin and generation system of this activity are uncertain. These pollutants in sedimentation dust may change to a more toxic form in vivo by S9 activation.  相似文献   

13.

With a growing awareness of environmental protection, the dust pollution caused by automobile foundry work has become a serious and urgent problem. This study aimed to explore contamination levels and health effects of automobile foundry dust. A total of 276 dust samples from six types of work in an automobile foundry factory were collected and analysed using the filter membrane method. Probabilistic risk assessment model was developed for evaluating the health risk of foundry dust on workers. The health risk and its influencing factors among workers were then assessed by applying the Monte Carlo method to identify the most significant parameters. Health damage assessment was conducted to translate health risk into disability-adjusted life year (DALY). The results revealed that the mean concentration of dust on six types of work ranged from 1.67 to 5.40 mg/m3. The highest health risks to be come from melting, cast shakeout and finishing, followed by pouring, sand preparation, moulding and core-making. The probability of the risk exceeding 10−6 was approximately 85%, 90%, 90%, 75%, 70% and 45%, respectively. The sensitivity analysis indicated that average time, exposure duration, inhalation rate and dust concentration (C) made great contribution to dust health risk. Workers exposed to cast shakeout and finishing had the largest DALY of 48.64a. These results can further help managers to fully understand the dust risks on various types of work in the automobile foundry factories and provide scientific basis for the management and decision-making related to health damage assessment.

  相似文献   

14.
浮尘对冬小麦叶片光合作用及细胞膜透性的影响   总被引:2,自引:0,他引:2  
我国是浮尘发生频繁的国家。浮尘作为一种灾害性天气不仅直接危害作物,而且通过减少直接辐射,减缓冰雪融化,减少河水流量,改变土壤性质等间接影响作物的生长发育。因此,深入研究浮尘对作物的影响具有重要意义。但目前,国内外的学者主要偏重研究人为粉尘和工业污染物对野生植物及绿化植物的影响,较少关注自然降尘对作物的影响;特别是在长期浮尘胁迫下冬小麦叶片的气孔导度、净光合速率、细胞质膜相对透性等生理指标的变化很少有研究。通过模拟降尘和盆栽试验,研究了拔节期和盛花期的降尘对冬小麦叶片温度(Tleaf)、叶绿素含量(Chl)、游离脯氨酸含量(Pro)、净光合速率(Pn)、气孔导度(Gs)、胞间CO2浓度(Ci)、细胞膜透性的影响(MP)。结果表明,降尘使拔节期和盛花期冬小麦的净光合速率分别下降52%和43.9%,差异均显著(P〈0.05);降尘还增大细胞膜透性,破坏了冬小麦自身调节系统,使拔节期和盛花期的叶绿素含量分别下降14.4%和20.4%,达到极显著差异(P〈0.01);降尘还使拔节期叶片的气孔导度下降到对照的26.9%(P〈0.05),同时叶面温度升高,脯氨酸含量增加38.2%。  相似文献   

15.
北京城市道路积尘多环芳烃的粒度分布特征及其影响因素   总被引:3,自引:0,他引:3  
对北京城市不同道路类型的道路积尘进行了为期16个月的采样,分别分析了道路尘的粒径、多环芳烃及TOC.道路积尘的粒径呈三峰态分布,<75 μm部分的颗粒所占体积最大,>214 μm部分颗粒所占体积最小.>214 μm这部分颗粒中的多环芳烃质量分数最低,<75μm和75~214μm这两部分颗粒中多环芳烃的质量分数没有显著差异,但由于<75μm部分颗粒所占的体积和质量比例最大,这部分颗粒的多环芳烃累积量所占比例最高.不同道路的积尘粒径存在差异,海淀路和成府路机动车道的积尘颗粒相比自行车道和人行道的颗粒更粗.由于粒径分布的差异和多环芳烃质量分数的差异,不同类型道路的多环芳烃累积量的粒径分布呈现差异.多环芳烃质量分数和累积量的粒度分布也呈现季节差异,冬春季<75 μm颗粒中的多环芳烃质量分数最高,多环芳烃的累积量所占比例也较夏秋季高.在三个粒级中,TOC与多环芳烃质量分数均呈现显著的正相关.高比例的细颗粒及细颗粒中的多环芳烃使得道路积尘再悬浮进入大气以及随湿沉降进入地表径流的环境风险加大.  相似文献   

16.
Over the past decade, ambient air particulate matter (PM) has been clearly associated with adverse health effects. In Brazil, small and poor communities are exposed to indoor dust derived from both natural sources, identified as blowing soil dust, and anthropogenic particles from mining activities. This study investigates the physicochemical and mineralogical composition of indoor PM10 dust samples collected in Minas Gerais, Brazil, and evaluates its cytotoxicity and inflammatory potential. The mean PM10 mass concentration was 206 μg/m3. The high dust concentration in the interior of the residences is strongly related to blowing soil dust. The chemical and mineralogical compositions were determined by ICP-OES and XRD, and the most prominent minerals were clays, Fe-oxide, quartz, feldspars, Al(hydr)oxides, zeolites, and anatase, containing the transition metals Fe, Cr, V, Ni, Cu, Zn, Ti, and Mn as well as the metalloid As. The indoor dust samples presented a low water solubility of about 6 %. In vitro experiments were carried out with human lung alveolar carcinoma cells (A549) to study the toxicological effects. The influence of the PM10 dust samples on cell viability, intracellular formation of reactive oxygen species (ROS), and release of the pro-inflammatory cytokine IL-8 was analysed. The indoor dust showed little effects on alamarBlue reduction indicating unaltered mitochondrial activity. However, significant cell membrane damage, ROS production, and IL-8 release were detected in dependence of dose and time. This study will support the implementation of mitigation actions in the investigated area in Brazil.  相似文献   

17.
采用粉煤灰(FA)和Ca(OH)2水合制得的高活性吸收剂作为二氧化硫的干法脱硫剂,重点研究了两种粉煤灰(电除尘灰和湿式水膜除尘灰)在同一配比、同一水合温度、同一水合时间下的脱硫效率,结果表明:电除尘灰比湿式水膜除尘灰脱硫效率高,并且电除尘的脱硫效率略微低于活性炭,同时介绍了粉煤灰的脱硫机理。  相似文献   

18.
The aim of this study was to investigate arsenic (As) accumulation in street dust and health risk of population. The investigation concentrated on: a. pollution levels of As in street dust; b. spatial distribution of As in street dust; c. physicochemical properties analysis of street dust; and d. assessment of population health risk due to As exposure to street dust. As concentration in street dust ranged from 3.33 to 185.1?mg?kg?1, with a mean of 33.10?mg?kg?1, which was higher than the background value of Liaoning soil. As contamination level of the area closing to Huludao Zinc Plant (HZP) was highest. Spatial variation showed that the pollution center was close to HZP, formed radial distribution pattern and extended to the northeast and southwest of HZP. The pH and organic matter of street dust were both higher than the background values of soil in Liaoning. There was significantly negative correlation between As concentration and the pH. The mass percentages of particles 180?C100,?<100?C75,?<75?C63, and?<63???m were 29.8, 3.7, 21.3, and 4.2?%, respectively. The highest of As concentration was found in the smallest particle size (<63???m). As loadings in the particles of grain size 180?C100 and?<75?C63???m were higher than other particle fractions. Results of the risk assessment indicated that the highest risk was associated with the ingestion of street dust particles. Health risk for different use scenarios to human decreased in the order of HZP?>?Industrial district?>?School?>?Commercial center?>?Residential area. Around HZP, Hazard Index (HI) for children and cancer risk of As by street dust exposure exceeded the acceptable values. It indicated that there was a potential adverse effect on children health by As exposure to the street dust of Huludao.  相似文献   

19.
为研究植物叶片重金属含量与滞尘之间的关系,对青岛市区道路绿化树种——圆柏(Sabinachinensis)叶片中Pb、zn、Cu、Cd4种重金属含量及其滞尘特征进行了系统分析,并在此基础上探讨了两者之间的关系。结果表明:不同距离和高度处的叶片Pb、Zn含量差异显著,与距离和高度呈负相关关系;叶片Cu含量与高度负相关,与距离相关性不显著;Cd含量则与距离和高度均没有显著相关关系。距离和高度对滞尘量有显著影响,而两者的交互作用对滞尘量的影响不显著,随着距离和高度的增加滞尘量逐渐减少。叶面尘中Pb、Zn含量空间分布差异较大,而Cu、Cd含量分布差异不显著。叶片重金属含量与相对应的叶面尘重金属含量之间具有显著正相关关系,除Cd以外叶片重金属含量与滞尘量之间也表现出不同程度的正相关关系。  相似文献   

20.
To understand the features and leaching characteristics of copper (Cu) scrap smelting dust and its potential risk to environment and humans, three types of smelting dust were sampled and investigated. The dust samples were collected from the dust captured by cyclone collector, panel cooler, and bag house in a typical Cu scrap smelting process of a factory in Guangxi of China. Zinc (Zn), Cu and lead (Pb) were the main elements of the samples of cyclone collector dust (CCD), panel cooler dust (PCD), and bag house dust (BHD). There were less arsenic (As), Pb and Cu in CCD than PCD and BHD, and PCD contained more manganese (Mn), nickel (Ni), and iron (Fe) than BHD. The particle shapes of BHD appeared more regular than CCD and PCD, and energy dispersive X-ray spectroscopy analysis illustrated the compositions of selected surface areas of three samples. The size of particles ranged from 0.011 to 33.11 μm in CCD, from less than 1 μm to several mm in PCD, and from 0.832 to 363.078 μm in BHD. The main elements in leachate were Zn and Mn from CCD, Zn, cadmium (Cd) and Pb from PCD, Zn, Mn and Cd from BHD. The leaching toxicity risk of Cd, Mn, and Zn of PCD and BHD was higher than CCD.  相似文献   

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