著者

東 朋美 神林 康弘 藤村 政樹 大倉 徳幸 吉崎 智一 中西 清香 西條 清史 早川 和一 小林 史尚 道上 義正 人見 嘉哲 中村 裕之

出版者

日本エアロゾル学会

雑誌

エアロゾル研究 (ISSN:09122834)

巻号頁・発行日

vol.29, no.1, pp.s212-s217, 2014

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The frequency and scale of Asian dust events have increased rapidly in East Asia since 2000. In connection with this, the effects of Asian dust (<i>kosa</i>) on human health, especially on allergic diseases, are major concern in Japan. We herein discuss the effects of <i>kosa</i> on allergic diseases, including asthma, chronic cough and Japanese cedar pollinosis. Epidemiological studies, as well as experimental studies, have demonstrated the association between <i>kosa</i> and the exacerbation of asthma and allergic diseases.The <i>kosa</i> particles increase airway inflammation as one of the major sources of atmospheric particulate matter. Furthermore the <i>kosa</i> particles absorb various atmospheric gases, including air pollution. Such environmental pollution enhances the response to allergens, including Japanese cedar pollen. Recently, some epidemiological studies used the <i>kosa</i> data obtained by the light detection and ranging (LIDAR) system, which distinguish between mineral dust and other spherical particles, by identifying differences in the shape of the particles. Further studies using the LIDAR system will help to identify the <i>kosa</i> aerosol components that have adverse health effects, leading to provide new strategies to prevent environmentally induced allergic diseases.

著者

堅田 元喜 永井 晴康

出版者

日本エアロゾル学会

雑誌

エアロゾル研究 (ISSN:09122834)

巻号頁・発行日

vol.25, no.4, pp.323-330, 2010 (Released:2011-01-18)

参考文献数

35

被引用文献数

2

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Recent progress in modeling particle deposition onto vegetation and the issues in validating these models are described in the present paper. Comparisons of size-dependent deposition velocity between calculations and observations may not be sufficient to validate individual modeled processes incorporated in the particle deposition model. The differences of environmental factors between measurements and calculations should be taken into account to validate the modeled processes depending on particle size ranges. Numerical simulations using detailed one-dimensional atmosphere-soil-vegetation model including particle deposition onto vegetation (SOLVEG) developed by the authors was carried out. The model reproduced the measured turbulent fluxes over the coniferous forest canopies for large (> 1 µm) and fine (< several 100 nm) particles. For the sub-micron particles, however, our model underestimated the measured particle deposition velocity obtained from various campaigns. Electrostatic deposition, thermo- and diffusio-phoretic deposition, micro-roughness such as cilium at the leaf surface, and particle growth under humid environment could affect particle deposition in this size range. Vegetation parameters such as Leaf Area Index (LAI) and leaf width also have a significant effect on the deposition velocity. This effect should be incorporated into future parameterizations of particle deposition velocity onto vegetation.

著者

竹村 俊彦

出版者

日本エアロゾル学会

雑誌

エアロゾル研究 (ISSN:09122834)

巻号頁・発行日

vol.24, no.4, pp.237-241, 2009-12-20 (Released:2009-12-25)

参考文献数

17

被引用文献数

1

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The aerosol effects on the climate system are roughly divided into three categories: direct, indirect, and semi-direct effects. Observations from satellites and ground with remote sensing and numerical models have been developed to understand and estimate aerosol effects on a global scale. In the latest assessment report of the Intergovernmental Panel on Climate Change (IPCC) , however, there are still large uncertainties in their radiative forcings in comparison with the estimation of long-lived greenhouse gases. To reduce the uncertainties, we have to study the three-dimensional aerosol distributions and the cloud-aerosol interaction more accurately. It is important to observe aerosol vertical profiles with lidar, one of the active sensors, to understand the three-dimensional aerosol distributions as well as to continue observations with passive sensors. The data assimilation, which harmonizes numerical models with observations, is also an effective method to reduce the uncertainties. A cloud resolving model coupled with an aerosol transport model is a useful tool to better understand the cloud-aerosol interaction. Efforts to analyze the aerosol climate effects quantitatively will result in more reliable projection of the future climate change and elucidating climate system.

著者

サマラス ジシス 白井 忠

出版者

日本エアロゾル学会

雑誌

エアロゾル研究 = Journal of aerosol research (ISSN:09122834)

巻号頁・発行日

vol.16, no.3, pp.190-196, 2001-09-20

著者

速水 洋 藤田 慎一

出版者

日本エアロゾル学会

雑誌

エアロゾル研究 (ISSN:09122834)

巻号頁・発行日

vol.21, no.4, pp.354-358, 2006-12-20 (Released:2007-03-29)

参考文献数

15

被引用文献数

5

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Concentrations of PM2.5 mass and inorganic ionic components measured in Komae, Tokyo, from FY1998 to FY2005 are analyzed for studying the interannual variability. It is found that the mass concentration tends to decrease annually, and this tendency is pronounced in winter. It is considered from the comparisons with other studies in South Kanto that the decreasing tendency is a relatively large-scale phenomenon, and the PM2.5 mass concentration is being uniformed in the area. Inorganic ionic species do not show such decreasing tendency in general. As a result, concentration ratios of secondary inorganic aerosol (SIA) to PM2.5 mass tend to increase. This could lead to the uniformity in PM2.5 mass concentration. The SIA concentration is high, very close to the US Air Quality Standard for PM2.5. Therefore, the SIA should be more concerned in order to reduce the PM2.5 mass concentration.

著者

坂本 和彦 広田 祐二 根津 豊彦 坪田 美佐 君島 克憲 奥山 正喜

出版者

日本エアロゾル学会

雑誌

エアロゾル研究 (ISSN:09122834)

巻号頁・発行日

vol.14, no.3, pp.242-247, 1999-09-20 (Released:2009-08-14)

参考文献数

6

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In order to investigate on particulate matter emission and generation by the traffic of heavy-duty vehicles on roads, total suspended particulate matter (TSP) were collected at the roadside along major local-road Urawa-Tokorosawa with high-volume air samplers during September 14∼16 and November 30∼December 5, 1992. Concentration of tire-dust in TSP was determined by a method based on the determination of thiophene derivatives generated by the pyrolysis of TSP. During the latter sampling period, ambient concentrations of tire-dust generated by the traffic of heavy-duty vehicles and passenger cars were 1.8∼5.9 and 2.7∼6.0 μgm-3, respectively. These results suggest that 3-methylthiophene be a suitable indicator of TSP emitted and generated from heavy-duty vehicles, because it is a specific pyrolyzate from tire-dust for trucks and buses. Concentration of elemental carbon (EC), most of which could be emitted by diesel-powered vehicles. Contributions of total tire-dust by heavy-duty vehicles and passenger cars to TSP and EC concentration were ca. 4 and ca. 20%, respectively.

著者

熊谷 貴美代

出版者

日本エアロゾル学会

雑誌

エアロゾル研究 (ISSN:09122834)

巻号頁・発行日

vol.26, no.4, pp.315-320, 2011 (Released:2011-12-28)

参考文献数

15

被引用文献数

1

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Observations of atmospheric aerosols were carried out at Maebashi and Mt Akagi located in the inland Kanto plain. Fine and coarse particles were collected using a low-volume air sampler, and organic carbon (OC), water-soluble organic carbon (WSOC), elemental carbon and ionic components were measured. The highest concentration of fine particles was observed in spring, and nitrate and sulfate were the major components. Sulfate and OC were dominant in summer and fall. We found that ammonium sulfate was widely distributed in the inland Kanto plain while ammonium nitrate was localized in Maebashi. The seasonal variation of WSOC concentration rising from summer to fall was observed at Maebashi. The WSOC/OC ratio increased in summer, suggesting that organic aerosols were influenced by aging. We focused on water-soluble organic components in fine particles; dicarboxylic acids as tracers of photochemical reaction products, and levoglucosan as a tracer of biomass burning emission. The concentrations of total diacids in spring and summer were higher than in winter. WSOC concentration showed highly positive correlation with total diacids concentration in each season. Levoglucosan observed was considerably high in winter. We found that the secondary formation is the dominant source of organic aerosols, especially in the warm seasons, and that biomass burning is another important source of organic aerosol in winter.

著者

浦 幸帆 長田 和雄 香川 雅子 三上 正男 的場 澄人 青木 一真 篠田 雅人 黒崎 泰典 林 政彦 清水 厚 植松 光夫

出版者

日本エアロゾル学会

雑誌

エアロゾル研究 (ISSN:09122834)

巻号頁・発行日

vol.26, no.3, pp.234-241, 2011 (Released:2011-09-28)

参考文献数

25

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Water-insoluble filtered residue materials of atmospheric wet and dry deposition are composed of mineral dusts and organic materials such as pollens. The number of pollens in the filter residue of deposition samples at Tottori was counted for 2 sizes at about 45 and 30 µm using a confocal laser microscope. Non-destructive X-ray fluorescence (XRF) analysis was used to measure Fe content of the filter residue. Relationship between Fe content analyzed by XRF and insoluble residue weight corrected for pollen weight assuming pollen density of 0.9 g/cm3 showed a linear relationship, suggesting that insoluble residue corrected for pollen weight contains Fe of 3.7 % by weight on the average. The average Fe content is consistent with the values reported for Asian dust (Kosa) events in Korea and China. Because Fe content of insoluble residue in filter samples is easily measured by XRF method, mineral dust amounts in the filter residue samples can be estimated from Fe content of the sample and the average fraction of Fe for Asian dust.

著者

阪田 総一郎 岡田 孝夫

出版者

日本エアロゾル学会

雑誌

エアロゾル研究 (ISSN:09122834)

巻号頁・発行日

vol.8, no.1, pp.37-45, 1993-03-20 (Released:2011-03-04)

参考文献数

11

被引用文献数

1

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The effect of moisture on the chemical formation of air ions produced by corona discharge in clean air, and the formation of large clusters were mainly discussed in this paper. We measured the composition of positive and negative air ions generated by corona discharge in clean air using an atmospheric pressure lonization mass spectrometer (APIMS). The positive ions were composed of H+(H2O)n (n= 1 , 2 , 3 , ……), and the negative ions of CO3-(H2O)n, O2-(H2O)n, NO3-, NO2-(H2O)n, O-, and O3-. The degree of hydration, n, in those hydrate ions increased with a moisture increase. Ultra-fine particles of nanometer size were detected in the ionized clean air with a CNC, and the number of them also increased with the moisture increase. Large hydrate ions which have high degrees of hydration, probably constitute those ultra-fine particles.

著者

林 政彦 岩坂 泰信

出版者

日本エアロゾル学会

雑誌

エアロゾル研究 (ISSN:09122834)

巻号頁・発行日

vol.5, no.4, pp.294-301, 1990-12-20 (Released:2011-06-14)

参考文献数

21

著者

山田 裕司 小泉 彰 宮本 勝宏

出版者

日本エアロゾル学会

雑誌

エアロゾル研究 = Journal of aerosol research (ISSN:09122834)

巻号頁・発行日

vol.11, no.1, pp.35-43, 1996-03-20

被引用文献数

7

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Aerosol penetrations through fibrous filters with pinholes were studied theoretically and experimentally. An equivalent thin filter layer (ETFL) model assuming a virtual filter layer was proposed to account for penetration through filters with pinholes. From one to thirty pinholes per filter were made on HEPA filter media using columnar pins of 0.195, 0.150 or 0.130 mm in diameter. Aerosol penetration through these filters was measured using monodisperse NaCl aerosols ranging from 0.05 to 0.3 μm in diameter at air flow face velocities of 0.00775, 0.0233 and 0.0698 m/s. Net penetration through the pinholes increased in proportion to the pinhole number and size. But there was no change in pressure drops across the filters. As a result of analysis based on the ETFL model, the layer thickness was estimated to range from 1/5 to 1/12 of the normal filter thickness. The predicted penetration curves were confirmed to agree well with the measured curves.

著者

児島 紘

出版者

日本エアロゾル学会

雑誌

エアロゾル研究 (ISSN:09122834)

巻号頁・発行日

vol.10, no.4, pp.265-270, 1995-12-20 (Released:2010-07-22)

参考文献数

21

被引用文献数

1

著者

飯沼 恒一

出版者

日本エアロゾル学会

雑誌

エアロゾル研究 (ISSN:09122834)

巻号頁・発行日

vol.18, no.1, pp.9-14, 2003-03-20 (Released:2007-11-27)

参考文献数

27

被引用文献数

1

著者

坂本 和彦 新井 哲也

出版者

日本エアロゾル学会

雑誌

エアロゾル研究 (ISSN:09122834)

巻号頁・発行日

vol.12, no.2, pp.130-134, 1997-06-20 (Released:2010-02-19)

参考文献数

16

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Particle formation by radiolysis was observed in the neutralizer of the differential mobility analyzer (DMA) in air or N2 under presence of O3 and/or SO2. The effects of SO2 concentration, relative humidity and O3 concentration on the particle formation in the neutralizer were investigated. This particle formation may cause artifacts in aerosol size-measuring using a DMA. The particle number concentration increased with increasing of SO2 concentration and relative humidity. In low humidity condition, remarkable increase of the number concentration was observed when 0.1 ppm of O3 was added to SO2 (0.2 ppm)/N2 (H2O < 15 ppm) mixture. The mechanisms of the particle formation in the neutralizer under presence of O3 were discussed.

著者

明星 敏彦 小笠原 真理子 浅井 琢也 松倉 正雄

出版者

日本エアロゾル学会

雑誌

エアロゾル研究 (ISSN:09122834)

巻号頁・発行日

vol.13, no.1, pp.35-43, 1998-03-20 (Released:2010-02-03)

参考文献数

17

被引用文献数

1

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This work describes the performance of the midget impinger for submicron aerosols. Collection efficiencies of the midget impinger were investigated numerically and experimentally. Flow fields in the midget impinger were solved using FLUENT, which is a computational fluid dynamics software and calculates RNG k-ε model for intermediate Re number, k-ε model for high Re number, and laminar flow model. Polystyrene latex (PSL) particles ranging from 0.10 to 3.1 μm and monodisperse diethyl-hexyl-sebacate (DEHS) mist ranging from 0.3 to 1.5 μm were aerosolized and introduced into the midget impinger. These theoretical and experimental results show a good agreement. The impinger shows poor performance for submicron particles and bubbling in the impinger contributes to 10% higher collection efficiency for submicron mist particles than that without water filling. PSL particles larger than 0.6 μm show bounce off the bottom surface of the impinger.

著者

向井 正

出版者

日本エアロゾル学会

雑誌

エアロゾル研究 (ISSN:09122834)

巻号頁・発行日

vol.22, no.2, pp.119-124, 2007-06-20 (Released:2007-06-20)

参考文献数

8

被引用文献数

1

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We present the current status of the research for interplanetary dust particles, based on the results recently obtained by space missions for exploration of primitive bodies, i.e. Stardust and Deep-impact missions to comets, and HAYABUSA mission to asteroid. The comet missions have suggested the existence of grain materials produced in high (beyond 1,000 K) temperature region, which implies the presence of radial convection of grains in the proto-planetary nebula. On the other hand, the asteroid mission has revealed that the asteroid Itokawa has low mass density of 1.95 g/cm3, and consequently it suggests high interior porosity of about 40 %. This evidence suggests that the occurrence of catastrophic collisional disruption of mother bodies yielded the high porosity aggregates consisting of fragment debris, as well as a large amount of dust particles in interplanetary space.

著者

江竜 和信 瀬戸 章文 水上 陽介 名倉 瑞紀 古内 正美 田島 奈穂子 加藤 孝晴 榎原 研正 大谷 吉生

出版者

日本エアロゾル学会

雑誌

エアロゾル研究 (ISSN:09122834)

巻号頁・発行日

vol.24, no.1, pp.24-29, 2009-03-20 (Released:2009-03-31)

参考文献数

8

被引用文献数

3

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Inertial filter, which classifies nanoparticles by inertial filtration, has been developed by Otani et al. (Aerosol and Air Quality Research, 7, 343-352 (2007) ) . The present work is aimed at formulating the fundamental design rules for the inertial filters with an appropriate cutoff size at a low pressure drop. We numerically calculated the classification performance for nanoparticles and compared the results with the experimental data obtained with TEM grids which has rigid and uniform structure as a model filter. As a result, thorough the theoretical calculation and experiments, (1) the collection efficiency of inertial filter can be successfully predicted by the conventional filtration theory based on the single fiber collection efficiency. (2) A filter with a finer fiber diameter can achieve smaller cutoff size at a lower pressure drop, however, the theoretical calculation suggested (3) an inertial filter consisting of fibers smaller than 14 μm cannot suppress the diffusional collection of nanoparticles with the diameter of 20 nm even at a filtration velocity of 30 m/s.