GRIMM Messgeräte weltweit in Publikationen vertreten

Indoor Air Quality Monitors

Title: The North Atlantic Marine Boundary Layer Experiment (NAMBLEX). Overview of the campaign held at Mace Head, Ireland, in summer 2002
Author: D. E. Heard, K. A. Read, J. Methven, S. Al-Haider,W. J. Bloss, G. P. Johnson, M. J. Pilling, P. W. Seakins et al.
Date of Publication: 2006
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The North Atlantic Marine Boundary Layer Experiment (NAMBLEX), involving over 50 scientists from 12 institutions, took place at Mace Head, Ireland (53.32 N, 9.90 W), between 23 July and 4 September 2002. A wide range of state-of-the-art instrumentation enabled detailed measurements of the boundary layer structure and atmospheric composition in the gas and aerosol phase to be made, providing one of the most comprehensive in situ studies of Correspondence to: the marine boundary layer to date. This overview paper describes the aims of the NAMBLEX project in the context of previous field campaigns in the Marine Boundary Layer (MBL), the overall layout of the site, a summary of the instrumentation deployed, the temporal coverage of the measurement data, and the numerical models used to interpret the field data. Measurements of some trace species were made for the first time during the campaign, which was characterised by predominantly clean air of marine origin, but more polluted air with higher levels of NOx originatingfrom continental regions was also experienced. This paper provides a summary of the meteorological measurements and Planetary Boundary Layer (PBL) structure measurements, presents time series of some of the longer-lived trace species (O3, CO, H2, DMS, CH4, NMHC, NOx, NOy, PAN) and summarises measurements of other species that are described in more detail in other papers within this special issue, namely oxygenated VOCs, HCHO, peroxides, organohalogenated species, a range of shorter lived halogen species (I2, OIO, IO, BrO), NO3 radicals, photolysis frequencies, the free radicals OH, HO2 and (HO2+6RO2), as well as a summary of the aerosol measurements. NAMBLEX was supported by measurements made in the vicinity of Mace Head using the NERC Dornier-228 aircraft. Using ECMWF windfields,
calculations were made of the air-mass trajectories arriving at Mace Head during NAMBLEX, and were analysed together with both meteorological and trace-gas measurements. In this paper a chemical climatology for the duration of the campaign is presented to interpret the distribution of air-mass origins and emission sources, and to provide aconvenient framework of air-mass classification that is used by other papers in this issue for the interpretation of observed variability in levels of trace gases and aerosols.

Title: Benthic boundary mixing and resuspension induced by internal seiches
Author: M. Gloor, A. Wüest und M. Münnich
Date of Publication: 1994
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The effect of internal seiches on horizontal hypolimnetic bottom currents and on the stationary well-mixed benthic boundary layer (BBL) induced by these currents was studied for 2 weeks in a small prealpine lake using thermistor strings, an acoustic current meter and a CTD (C: conductivity, T: temperature, D: depth) equipped with a transmissometer. 150 profiles of temperature, conductivity and transmissivity taken during two days clearly indicate the existence of a well-mixed BBL 2 to 7 m thick. This is the result of intense mixing in the zone of high shear above the sediment associated with seiching motion. The concentration of suspended or resuspended particles, mainly of organic nature, within the BBL, was 2 to 4 times greater than that measured directly above the BBL. Resuspension is thought to be associated rather with high-frequency burst-like currents with measured speeds ranging up to 7 cm s^–1 than with the average bottom current speed of about 2 cm s^–1.

Title: Modeling the resuspension of ash deposited during the eruption of Eyjafjallajökull in spring 2010
Author: S. J. Leadbetter, M. C. Hort, S. von Löwis, K. Weber, and C. S. Witham
Date of Publication: 2012
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Eyjafjallajökull, a volcano in southern Iceland, erupted explosively in April and May 2010 depositing ash over a region of more than 3000 km2 to the east and southeast of the volcano. This deposited ash has been frequently remobilized by the wind causing concern for the health of Icelanders living in the region. An investigation was carried out to determine whether it would be possible to produce forecasts of days when high airborne ash concentrations were likely to occur. Information about the spatially varying surfacecharacteristics of the region of deposited ash is not available so in the modeling approach adopted here ash is released from the surface at a rate proportional to the cube of the excess friction velocity (local friction velocity minus a threshold) only when the friction velocity exceeds a threshold. Movement of the resuspended ash is then modeled in a Lagrangian
dispersion model. Modeled ash concentrations are compared to observed concentrations from two periods; PM10 observations between 23 May and 2 July 2010 and airborne particle counts between 21 September 2010 and 16 February 2011. More than 66% of the resuspension episodes between May and July are captured by the model and the relative magnitudes of the modeled episodes in this period are in good agreement with the observations. 66% of episodes between October and February are also captured by the model although there is an increase in the false alarm rate which appears to be due to the influence of precipitation.

Title: Spatial distribution and vertical structure of the MABL aerosols over Bay of Bengal during winter: Results from W-ICARB experiment
Author: .R. Sinhaa, R.K. Manchandaa, J.V. Subbaraoa, U.C. Dumkaa, S. Sreenivasana, S. Suresh Babub, Corresponding Author Contact Information, E-mail The Corresponding Author, E-mail The Corresponding Author and K. Krishna Moorthyb
Date of Publication: 2011
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The first ever in-situ measurements of size-segregated vertical profiles of aerosol in the marine atmospheric boundary layer (MABL) over the Bay of Bengal (BoB), made at five different locations during the winter Integrated Campaign of Aerosols, gases and Radiation Budget (W_ICARB) experiment is presented which showed large spatial variability in aerosol properties over BoB with high aerosol concentration over northern BoB (>500 cm−3) and low aerosol concentration (≤100 cm−3) over southern BoB with a moderate aerosol concentration (250–450 cm−3) over far east BoB. The altitude variation of aerosol number density is found to be steady in the convective boundary layer (up to not, vert, similar400 m) at all locations over BoB and above that the aerosol concentration is found to decrease, except at far eastern BoB. Over far eastern BoB, the altitude distribution of aerosol number concentration showed an increase at not, vert, similar600 m. Examination of the simultaneous air mass back trajectories along with the observations aerosol size distribution indicates that while the aerosols advected from IGP have a strong natural (coarse mode) component where as those from the east-Asia region are in general accumulation mode (anthropogenic) dominant.

Title: Spatial heterogeneities in aerosol size distribution over Bay of Bengal during Winter-ICARB Experiment
Author: P.R. Sinhaa, R.K. Manchandaa, , , D.G. Kaskaoutisb, S. Sreenivasana, K. Krishna Moorthyc and S. Suresh Babuc
Date of Publication: 2011
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This work examines the aerosol physical properties and size distribution measured in the Marine Atmospheric Boundary Layer (MABL) over entire Bay of Bengal (BoB) and Northern Indian Ocean (NIO) during the Winter Integrated Campaign on Aerosols, Gases and Radiation Budget (W-ICARB). The measurements were taken using the GRIMM optical particle counter from 27th December 2008 to 30th January 2009. The results show large spatial heterogeneities regarding both the total aerosol number concentrations (NT) and the size distributions over BoB, which in turn indicates the variations in the source strength or advection from different regions. The aerosol number size distribution seems to be bi-modal in the 72% of the cases and can also be parameterized by uni-modal or by a combination of power-law and uni-modal distributions for the rest of the cases. The mode radius for accumulation and coarse-mode particles ranges from not, vert, similar 0.1–0.2 μm and not, vert, similar0.6–0.8 μm, respectively. In the northern BoB and along the Indian coast, the aerosols are mainly of sub-micron size with effective radius (Reff) ranging between 0.25 and 0.3 μm highlighting the strong anthropogenic influence, while in the open oceanic areas they are much higher (0.4–0.6 μm). It was also found that the sea-surface wind plays a considerable role in the super-micron number concentration, Reff and mode radius for coarse-mode aerosols. Using the relation between NT and columnar AOD from Terra and Aqua-MODIS we found that the majority of the aerosols are within the lower MABL, while in some areas vertical heterogeneities also exist

Title: Ozone over the Western Mediterranean Sea - results from two years of shipborne measurements
Author: K. Velchev, F. Cavalli, J. Hjorth, E. Marmer, E. Vignati, F. Dentener, and F. Raes
Date of Publication: 2011
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Ozone, along with other air pollutants, has been measured for two years from a monitoring station placed on a cruise ship that follows a regular track in the Western Mediterranean between April and October. Conditions favouring high ozone levels have been studied by analysis of weather maps and back trajectories. This analysis was focused on a transect over the open sea in the South Western Mediterranean between Tunis and Palma de Mallorca. High ozone levels were found in situations with an anticyclonic circulation over the Western Mediterranean when subsidence brings air masses down from altitudes between 1000 and 3500 m a.s.l. Analysis of composite meteorological maps suggests a relevant contribution of breeze circulation to subsidence during events with high surface ozone concentrations; this points to an important contribution from local ozone formation. A detailed back trajectory analysis of the origin of air masses with high ozone concentrations was carried out for two "hot spots" for ozone pollution, in the Gulf of Genoa and between Naples and Palermo, respectively. The main cause of high ozone levels in the Gulf of Genoa was found to be outflow from the Po Valley and the Genoa area while such episodes along the Naples-Palermo transect were most often associated with trajectories from the Rome or Naples areas. Analysis of the relationship between measured concentrations of Black Carbon and ozone allowed to evaluate the degree of photochemical "ageing" of the air masses encountered along the route of the cruise ship.

Title: Airborne observations of the Eyjafjalla volcano ash cloud over Europe during air space closure in April and May 2010
Author: U. Schumann, B.Weinzierl, O. Reitebuch, H. Schlager, A. Minikin
Date of Publication: 2011
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Product: 1129

Airborne lidar and in-situ measurements of aerosols and trace gases were performed in volcanic ash plumes over Europe between Southern Germany and Iceland with the Falcon aircraft during the eruption period of the Eyjafjalla1 volcano between 19 April and 18 May 2010. Flight planning and measurement analyses were supported by a refined Meteosat ash product and trajectory model analysis. The volcanic ash plume was observed with lidar directly over the volcano and up to a distance of 2700 km downwind, and up to 120 h plume ages. Aged ash layers were between a few 100m to 3 km deep, occurred between 1 and 7 km altitude, and were typically 100 to 300 km wide. Particles collected by impactors had diameters up to 20 μm diameter, with size and age dependent composition. Ash mass concentrations were derived from optical particle spectrometers for a particle density of 2.6 g cm−3 and various values of the refractive index (RI, real part: 1.59; 3 values for the imaginary part: 0, 0.004 and 0.008). The mass concentrations, effective diameters and related optical properties were compared with ground-based lidar observations. Theoretical considerations of particle sedimentation constrain the particle diameters to those obtained for the lower RI values. The ash mass concentration results have an uncertainty of a factor of two. The maximum ash mass concentration encountered during the 17 flights with 34 ash plume penetrations was below 1 mgm−3. The Falcon flew in ash clouds up to about 0.8 mgm−3 for a few minutes and in an ash cloud with approximately 0.2 mgm−3 mean-concentration for about one hour without engine damage. The ash plumes were rather dry and correlated with considerable CO and SO2 increases and O3 decreases. To first order, ash concentration and SO2 mixing ratio in the plumes decreased by a factor of two within less than a day. In fresh plumes, the SO2 and CO concentration increases were correlated with the ash mass concentration. The ash plumes were often visible slantwise as faint dark layers, even for concentrations below 0.1 mgm−3.

Title: South African EUCAARI - measurements: a site with high atmospheric variability
Author: L. Laakso1,2,9, V. Vakkari2, H. Laakso2, A. Virkkula2, et al
Date of Publication: 2010
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In this paper, new long-term measurements of chemical composition and physical properties of atmospheric aerosols carried out on the eastern brink of the heavily polluted Highveld area in South Africa are introduced. As expected, a high variability of aerosol properties was observed. Optical properties of aerosol particles were found to be closely correlated with particulate mass and number concentration in the case of polluted air masses. In contrast, in clean conditions there was no clear connection between optical properties and aerosol number concentration due to the presence of multiple sources including new particle formation.

Title: Comparison of the Grimm 1.108 and 1.109 Portable Aerosol Spectrometer to the TSI 3321 Aerodynamic Particle Sizer for Dry Particles
Author: THOMAS M. PETERS*, DARRIN OTT and PATRICK T. O’SHAUGHNESSY
Date of Publication: 2010
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This study compared the response of two optical particle counters with that of an aerodynamic particle sizer. The optical particle counters rely on the amount of incident light scattered at 90 by a particle to measure particle number concentration by optical particle size. Two models of optical particle counters from Grimm Technologies were used: the portable aerosol spectrometer (PAS) 1.108 (0.3–20 mm in 15 channels); and the PAS 1.109 (0.2–20 mm in 30 size channels). With a substantially different operating principle from that employed by the optical particle counters, the aerodynamic particle sizer (APS) model 3321 (TSI, Inc., St Paul, MN, USA) sizes particles according to their behavior in an accelerating flow to provide particle number concentration by aerodynamic size over a slightly narrower size range (0.5–20 mm) in 52 channels. The responses of these instruments were compared for three sizes of monodisperse solid aerosols composed of polystyrene latex spheres and a polydisperse aerosol composed of Arizona test dust. The PASs provided similar results to those from the APS. However, there were systematic differences among instruments in number and mass concentration measurement that depended upon particle size.

Title: Temporal and vertical variations of aerosol physical and chemical properties over West Africa: AMMA aircraft campaign in summer 2006
Author: A. Matsuki1,4, B. Quennehen1,2, A. Schwarzenboeck1,2, S. Crumeyrolle2,3, H. Venzac1,2, P. Laj1,2,5, and L. Gomes3
Date of Publication: 2010
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While the Sahelian belt in West Africa stretches in the border between the global hot-spots of mineral dust and biomass burning aerosols, the presence of West African Monsoon is expected to create significant vertical and temporal variations in the regional aerosol properties through transport and mixing of particles from various sources (mineral dust, biomass burning, sulfates, sea salt). In order to improve our understanding of the evolution of the aerosolcloud system over such region across the onset of the summer monsoon, the French ATR-42 research aircraft was deployed in Niamey, Niger (13° 30' N, 02° 05' E) in summer 2006, during the three special observation periods (SOPs) of the African Monsoon Multidisciplinary Analysis (AMMA) project. These three SOPs covered both dry and wet periods before and after the onset of the Western African Monsoon. State of the art physico-chemical aerosol measurements on the ATR-42 showed a notable seasonal transition in averaged number size distributions where (i) the Aitken mode is dominating over the accumulation mode during the dry season preceding the monsoon arrival and (ii) the accumulation mode increasingly gained importance after the onset of theWest African monsoon and even dominated the Aitken mode after the monsoon had fully developed. The parameters for the mean log-normal distributions observed in respective layers characterized by the different wind regimes (monsoon layer, SAL, free troposphere) are presented, together with the major particle compositions found in the accumulation mode particles. Thereby, results of this study should facilitate radiative transfer calculations, validation of satellite remote sensors, and detailed transport modeling by partners within and outside the AMMA community. Extended analysis of the chemical composition of single aerosol particles by a transmission electron microscope (TEM) coupled to an energy dispersive X-ray spectrometer (EDX) revealed dominance of mineral dust (aluminosilicate) even in the submicron particle size range during the dry period, gradually replaced by prevailing biomass burning and sulfate particles, after the onset of the monsoon period. The spatial and temporal evolution from SOP1 to SOP2a1 and SOP2a2 of the particle physical and chemical properties and associated aerosol hygroscopic properties are remarkably consistent.

Title: Characterizing the performance of two optical particle counters (Grimm OPC1.108 and OPC1.109) under urban aerosol conditions
Author: J. Burkart, G. Steiner, G. Reischl, H. Moshammer, M. Neuberger and R. Hitzenberger
Date of Publication: 2010
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The performance of Grimm optical particle counters (OPC, models 1.108 and 1.109) was characterized under urban aerosol conditions. Number concentrations were well correlated. The different lower cut-off diameters (0.25 and 0.3 μm) give an average difference of 23.5%. Both detect less than 10% of the total particle concentration (0.01–1 μm; Differential Mobility Analyzer), but in the respective size ranges, differences are <10%. OPC number size distributions were converted to mass concentrations using instrument-specific factors given by the manufacturer. Mass concentrations for OPC1.108 were 60% higher than for OPC1.109 and (in case of OPC1.109) much lower than those measured with an impactor in the relevant size range or a TSP filter. Using the C-factor correction suggested by the manufacturer, OPC1.109 underestimated mass concentrations by 21% (impactor) and by about 36% (TSP filter), which is in the range of comparability of co-located different mass concentration methods (Hitzenberger, Berner, Maenhaut, Cafmeyer, Schwarz, & Mueller et al., 2004).

Title: Measured and predicted aerosol light scattering enhancement factors at the high alpine site Jungfraujoch
Author: R. Fierz-Schmidhauser, P. Zieger, M. Gysel, L. Kammermann, P. F. DeCarlo, U. Baltensperger, and E.Weingartner
Date of Publication: 2010
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Product: 1108

Ambient relative humidity (RH) determines the water content of atmospheric aerosol particles and thus has an important influence on the amount of visible light scattered by particles. The RH dependence of the particle light scattering coefficient ( sigma sp) is therefore an important variable for climate forcing calculations. We used a humidification system for a nephelometer which allows for the measurement of sigma sp at a defined RH in the range of 20–95%. In this paper we present measurements of light scattering enhancement factors f (RH)= Sigma sp(RH)/ Sigma sp(dry) from a 1-month campaign (May 2008) at the high alpine site Jungfraujoch (3580ma.s.l.), Switzerland. Measurements at the Jungfraujoch are representative for the lower free troposphere above Central Europe. For this aerosol type hardly any information about the f (RH) is available so far. At this site, f (RH=85%) varied between 1.2 and 3.3. Measured f (RH) agreed well with f (RH) calculated with Mie theory using measurements of the size distribution, chemical composition and hygroscopic diameter growth factors as input. Good f (RH) predictions at RH<85% were also obtained with a simplifiedmodel, which uses the Angström exponent of Sigma sp(dry) as input. RH influences further intensive optical aerosol properties. The backscatter fraction decreased by about 30% from 0.128 to 0.089, and the single scattering albedo increased on average by 0.05 at 85% RH compared to dry conditions. These changes in sp, backscatter fraction and single scattering albedo have a distinct impact on the radiative forcing of the Jungfraujoch aerosol.

Title: Cloud processing of mineral dust: direct comparison of cloud residual and clear sky particles during AMMA aircraft campaign in summer 2006
Author: A. Matsuki1,3, A. Schwarzenboeck1, H. Venzac1, P. Laj1, S. Crumeyrolle2, and L. Gomes2
Date of Publication: 2010
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In order to gain insights into the characteristics of the mineral dust particles incorporated in the actual cloud droplets and the related cloud processing, the French ATR- 42 research aircraft equipped both with a counterflow virtual impactor (CVI) and community aerosol inlet was deployed in Niamey, Niger (13°30' N, 02° 05' E) in August 2006 within the framework of the African Monsoon Multidisciplinary Analysis (AMMA) project.
Cloud residual and clear-sky particles were collected separately and analyzed individually using a transmission electron microscope (TEM) and a scanning electron microscope coupled with an energy dispersive X-ray spectroscopy (SEM-EDX). The analysis revealed interesting characteristics on the coarse dust particles (Dp>1μm), particularly those which likely had acted as CCN.
Traces of heterogeneously formed secondary sulfate, chloride and nitrate were found on many dust particles (though fraction of sulfate may be present in the form of gypsum as primary dust component). These secondary species were particularly enhanced in clouds (i.e. cloud processing). The study illustrates that calcium-rich particles assumed to be carbonates (Calcite, Dolomite) contained the secondary species in significantly larger frequency and amount than the silicates (Quartz, Feldspar, Mica, Clay), suggesting that they represent the most reactive fraction of the mineral dust. A surprisingly large fraction of the Ca-rich particles were already found in deliquesced form even in clear-sky conditions, most probably reflecting their extreme hygroscopicity,resulting from their reaction with HNO3 gas.
Both silicate and Ca-rich particles were found dominant among the supermicron cloud residues, and they were supposed to be those previously activated as CCN. It is highly probable that the observed formation of soluble materials enhanced their cloud nucleating abilities.

Title: The Mobile Air Quality Study (MAQS)-an international project
Author: David A Groneberg, Cristian Scutaru*, Mathias Lauks, Masaya Takemura, Tanja C Fischer, Silvana Kölzow
Date of Publication: 2010
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Product: 1109

Due to an increasing awareness of the potential hazardousness of air pollutants, new laws, rules and guidelines have recently been implemented globally. In this respect, numerous studies have addressed traffic-related exposure to particulate matter using stationary technology so far. By contrast, only few studies used the advanced technology of mobile exposure analysis. The Mobile Air Quality Study (MAQS) addresses the issue of air pollutant exposure by combining advanced high-granularity spatial-temporal analysis with vehicle-mounted, person-mounted and roadside sensors. The MAQS-platform will be used by international collaborators in order 1) to assess air pollutant exposure in relation to road structure, 2) to assess air pollutant exposure in relation to traffic density, 3) to assess air pollutant exposure in relation to weather conditions, 4) to compare exposure within vehicles between front and back seat (children) positions, and 5) to evaluate "traffic zone"-exposure in relation to non-"traffic zone"-exposure.Primarily, the MAQS-platform will focus on particulate matter. With the establishment of advanced mobile analysis tools, it is planed to extend the analysis to other pollutants including NO2, SO2, nanoparticles and ozone.

Title: Road Dust Emissions from Paved Roads Measured Using Different Mobile Systems
Author: Liisa Pirjola, Christer Johansson, Kaarle Kupiainen, et al
Date of Publication: 2010
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Product: 1109

Very few real-world measurements of road dust suspension have been performed to date. This study compares two different techniques (referred to as Sniffer and Emma) to measure road dust emissions. The main differences between the systems are the construction of the inlet, different instruments for recording particulate matter (PM) levels, and different loads on the wheel axes (the weight of Sniffer was much higher than that of Emma). Both systems showed substantial small-scale variations of emission levels along the road, likely depending on-road surface conditions. The variations observed correlated quite well, and the discrepancies are likely a result of variations in dust load on the road surface perpendicular to the driving direction that cause variations in the measurements depending on slightly different paths driven by the two vehicles. Both systems showed a substantial influence on the emission levels depending on the type of tire used. The summer tire showed much lower suspension than the winter tires (one nonstudded and one studded). However, the relative importance of the nonstudded versus studded tire was rather different. For the ratio of studded/nonstudded, Emma shows higher values on all road sections compared with Sniffer. Both techniques showed increased emission levels with increasing vehicle speed. When the speed increased from 50 to 80 km hr_1, the relative concentrations increased by 30–170% depending on the tire type and dust load. However, for road sections that were very dirty, Sniffer showed a much higher relative increase in the emission level with the nonstudded tire. Sniffer’s absolute concentrations were mostly higher than Emma’s. Possible reasons for the differences are discussed in the paper. Both systems can be used for studying relative road dust emissions and for designing air quality management strategies.

Title: Emission and dry deposition of accumulation mode particles in the Amazon Basin
Author: L. Ahlm1, R. Krejci1, E. D. Nilsson1, E. M. M°artensson1, M. Vogt1, and P. Artaxo2
Date of Publication: 2010
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Product: 1109

Size-resolved vertical aerosol number fluxes of particles in the diameter range 0.25–2.5 μm were measured with the eddy covariance method from a 53 m high tower over the Amazon rain forest, 60 km NNW of Manaus, Brazil. This study focuses on data measured during the relatively clean wet season, but a shorter measurement period from the more polluted dry season is used as a comparison. /Size-resolved net particle fluxes of the five lowest size bins, representing 0.25–0.45 μm in diameter, were in general dominated by deposition in more or less all wind sectors in the wet season. This is an indication that the source of primary biogenic aerosol particles may be small in this particle size range. Transfer velocities within this particle size range were observed to increase linearly with increasing friction velocity and increasing particle diameter. /In the diameter range 0.5–2.5 μm, vertical particle fluxes were highly dependent on wind direction. In wind sectors where anthropogenic influence was low, net upward fluxes were observed. However, in wind sectors associated with higher anthropogenic influence, deposition fluxes dominated. The net upward fluxes were interpreted as a result of primary biogenic aerosol emission, but deposition of anthropogenic particles seems to have masked this emission in wind sectors with higher anthropogenic influence. The net emission fluxes were at maximum in the afternoon when the mixed layer is well developed, and were best correlated with horizontal wind speed according to the equation log10 F=0.48 · U+2.21 where F is the net emission number flux of 0.5–2.5 μm particles [m−2 s−1] and U is the horizontal wind speed [ms−1] at the top of the tower.

Title: Black carbon measurements in the boundary layer over western and northern Europe
Author: G. R. McMeeking1, T. Hamburger2, D. Liu1, M. Flynn1
Date of Publication: 2010
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Product: 1129

Europe is a densely populated region that is a significant global source of black carbon (BC) aerosol, but there is a lack of information regarding the physical properties and spatial/vertical distribution of rBC in the region. We present the first aircraft observations of sub-micron refractory BC (rBC) aerosol concentrations and physical properties measured by a single particle soot photometer (SP2) in the lower troposphere over Europe. The observations spanned a region roughly bounded by 50_ to 60_ N and from 15_Wto 30_ E. The measurements, made between April and September 2008, showed that average rBC mass concentrations ranged from about 300 ngm−3 near urban areas to approximately 50 ngm−3 in remote continental regions, lower than previous surface-based measurements. rBC represented between 0.5 and 3% of the sub-micron aerosol mass. Black carbon mass size distributions were log-normally distributed and peaked at approximately 180 nm, but shifted to smaller diameters (_160 nm) near source regions. rBC was correlated with carbon monoxide (CO) but had different ratios to CO depending on location and air mass. Light absorption coefficients were measured by particle soot absorption photometers on two separate aircraft and showed similar geographic patterns to rBC mass measured by the SP2. We summarize the rBC and light absorption measurements as a function of longitude and air mass age and also provide profiles of rBC mass concentrations and size distribution statistics. Our results will help evaluate model-predicted regional rBC concentrations and properties and determine regional and global climate impacts from rBC due to atmospheric heating and surface dimming.

Title: Evaluation Of The Overall Particle Emission Reduction Efficiencies Of Commercially Available Laser Printer Filters
Author: G. Steiner, D. Wimmer, G.P. Reischl, E. Peteln, M. Vojta
Date of Publication: 2009
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The performance of three commercially available filter systems [improved DEXWET filter system Modular Professional 2000 (DW), Filter A and Filter B], specially assigned for office machines was investigated. Therefore, the overall particle emissions evolving from a standard b/w laser printer during a print job were investigated, using a specially designed exposition test chamber with a volume of 0.4 m³. Measurements with and without mounted filter systems were performed.

Title: Real-Time Monitoring of Arsenic, Cadmium, Copper, and Lead Concentrations in Copper Smelter Particulates Using a TSI 8520 DustTrak, a Haz-Dust EPAM-5000, and a Grimm 1.109
Author: J. Freestone, J. McDonald, J. Mecham, L. Pahler, R. Larson
Date of Publication: 2009
Hyperlink: http://www.aiha.org/education/meetings-conferences/aihce/archivedabstracts/2010abstracts/Documents/2010_Aerosol_Technology_Abstracts.pdf
Product: 1109

Exposure to arsenic, cadmium, copper, and lead in workplace particulates is a potential health concern in the copper smelter where this study was conducted. Standard sampling and analytical analysis of metals in particulates requires1 to 2 weeks before results are available. The purpose of this study is to determine if the commercially available TSI 8520 DustTrak, Haz‐Dust EPAM‐5000, and Grimm 1.109 real‐time aerosol‐monitoring instruments in conjunction with specific correction factors provided by this study can provide acceptable approximations of arsenic, cadmium, copper, and lead concentrations determined by standard sampling and analytical techniques. Methods: Copper smelter particulates were sampled during 16 sampling events using matched weight Mixed Cellulose Ester (MCE) filter cassettes while simultaneously monitoring particulates with a DustTrak, a Haz‐Dust, and a Grimm real‐time aerosol monitoring instrument. Cassette filters were analyzed using an inductively coupled plasma mass spectrometry (ICP‐MS) instrument to determine the concentrations of arsenic, cadmium, copper, and lead. Individual linear regressions with the yintercept forced to zero were developed to determine the relationship between measurements recorded by these three instruments and laboratory‐reported arsenic, cadmium, copper, and lead concentrations. Results: Linear regressions yielded correction factors that can be applied to the three aerosol monitoring instrument readings to obtain relative concentrations for each of the four metals. The coefficient of determination (R2) values from the linear regressions were 0.70 to 0.94 for arsenic, 0.67 to 0.82 for cadmium, 0.70 to 0.91 for copper, and 0.54 to 0.93 for lead. Conclusions: These results suggest that the TSI 8520 DustTrak, the Haz‐Dust, and the Grimm 1.109 instruments may provide real‐time data useful in providing estimates for concentrations of arsenic, cadmium, copper, and lead in copper smelter particulates, although percent compositions of the metals in these particulates seem to be variable. These results suggest additional studies are needed for verification.,

Title: Chemistry and transport of pollution over the Gulf of Mexico and the Pacific: spring 2006 INTEX-B campaign overview and first results
Author: H. B. Singh, W. H. Brune, J. H. Crawford, F. Flocke, and D. J. Jacob
Date of Publication: 2009
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Product: 1109

Intercontinental Chemical Transport Experiment- B (INTEX-B) was a major NASA (Acronyms are provided in Appendix A.) led multi-partner atmospheric field campaign completed in the spring of 2006 (http://cloud1.arc.nasa.gov/intex-b/). Its major objectives aimed at (i) investigating the extent and persistence of the outflow of pollution from Mexico; (ii) understanding transport and evolution of Asian pollution and implications for air quality and climate across western North America; and (iii) validating space-borne observations of tropospheric composition. INTEX-B was performed in two phases. In its first phase (1–21 March), INTEX-B operated as part of the MILAGRO campaign with a focus on observations over Mexico and the Gulf of Mexico. In the second phase (17 April–15 May), the main INTEX-B focus was on trans-Pacific Asian pollution transport. Multiple airborne platforms carrying state of the art chemistry and radiation payloads were flown in concert with satellites and ground stations during the two phases of INTEX-B. Validation of Aura satellite instruments (TES, OMI, MLS, HIRDLS) was a key objective within INTEX-B. Satellite products along with meteorological and 3-D chemical transport model forecasts were integrated into the flight planning process to allow targeted sampling of air parcels. Inter-comparisons were performed among and between aircraft payloads to quantify the accuracy of data and to create a unified data set. Pollution plumes were sampled over the Gulf of Mexico and the Pacific several days after downwind transport from source regions. Signatures of Asian pollution were routinely detected by INTEX-B aircraft, providing a valuable data set on gas and aerosol composition to test models and evaluate pathways of pollution transport and their impact on air quality and climate. This overview provides details about campaign implementation and a context within which the present and future INTEX-B/MILAGRO publications can be understood.

Title: Mexico City aerosol analysis during MILAGRO using high resolution aerosol mass spectrometry at the urban supersite (T0)
Author: A. C. Aiken1,2,*, D. Salcedo3, M. J. Cubison2, J. A. Huffman1,2, P. F. DeCarlo2,4,*, I. M. Ulbrich1,2, et al.
Date of Publication: 2009
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Product: 110x

Submicron aerosol was analyzed during the MILAGRO field campaign in March 2006 at the T0 urban supersite in Mexico City with a High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) and complementary instrumentation. Mass concentrations, diurnal cycles, and size distributions of inorganic and organic species are similar to results from the CENICA supersite in April 2003 with organic aerosol (OA) comprising about half of the fine PM mass. Positive Matrix Factorization (PMF) analysis of the high resolution OA spectra identified three major components: chemically-reduced urban primary emissions (hydrocarbon-like OA, HOA), oxygenated OA (OOA, mostly secondary OA or SOA), and biomass burning OA (BBOA) that correlates with levoglucosan and acetonitrile. BBOA includes several very large plumes from regional fires and likely also some refuse burning. A fourth OA component is a small local nitrogen-containing reduced OA component (LOA) which accounts for 9% of the OA mass but one third of the organic nitrogen, likely as amines. OOA accounts for almost half of the OA on average, consistent with previous observations. OA apportionment results from PMF-AMS are compared to the PM2.5 chemical mass balance of organic molecular markers (CMB-OMM, from GC/MS analysis of filters). Results from both methods are overall consistent. Both assign the major components of OA to primary urban, biomass burning/woodsmoke, and secondary sources at similar magnitudes. The 2006 Mexico City emissions inventory underestimates the urban primary PM2.5 emissions by a factor of ~4, and it is ~16 times lower than afternoon concentrations when secondary species are included. Additionally, the forest fire contribution is at least an order-of-magnitude larger than in the inventory.

Title: Ionization for reducing particulate matter emissions from poultry houses
Author: M. Cambra-López, A. Winkel, J. van Harn, N. W. M. Ogink, A. J. A. Aarnink
Date of Publication: 2009
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Product: 1109

We evaluated the effect of ionization in reducing particulate and gaseous emissions in broiler houses and its effect on particle size distribution. Furthermore, we evaluated the performance of the tested ionization system and its influence on bird performance. The experiment was done during two consecutive rearing cycles in a pilot‐scale broiler house with four identical rooms. We measured concentrations of PM10 and PM2.5, airborne micro‐organisms, ammonia, and odor of the incoming and outgoing air. Emissions were calculated by multiplying measured concentration difference of each pollutant by measured ventilation exchange rates. Performance of the system was evaluated through quantifying ion concentration, ozone production, and ultrafine particle concentration. Moreover, we recorded bird weight gain, consumption variables, mortality, exterior quality, and foot pad lesions. Overall measured mass emissions reductions were 36% for PM10 and 10% for PM2.5. Total mass was reduced less for PM2.5 because reduction efficiency decreased to the end of the growing period (P < 0.10). This coincided with increased particulate concentrations, increased ventilation exchange rates, and dust accumulation on surfaces. Higher reduction efficiencies were observed in relation to increased particle size. Ionization did not have a significant effect on micro‐organism, ammonia, or odor emissions or on bird performance. Ionization proved to be a practical and effective technique for particulate reduction, with minimal maintenance required for use in broiler houses. It is recommended to evaluate the use of ionization in commercial broiler houses to validate these results.,

Title: Physical and Biochemical Properties of Airborne Flour Particles Involved in Occupational Asthma
Author: MICHEL LAURIE`RE*, PETER GORNER, ISABELLE BOUCHEZ-MAHIOUT, et al
Date of Publication: 2008
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Product: 1105

Aerosol particles which deeply penetrate the human airways and which trigger baker’s asthma manifestations are known to represent only a part of flour and of airborne particles found in bakeries. They were a major focus of this study. To this end, aerosols were produced from different wheat and rye flours, using an automatic generator designed for bronchial challenge. Particles were characterized for their size distribution, their ability to be deposited in the airways, their protein content, their histological composition and their reactivity with immunoglobulin E (IgE) present in sera from asthmatic bakers. Like dust particles collected in the bakery, the aerosols produced showed increased protein content but decreased IgE reactive protein content when compared to the corresponding bulk flours. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of these particles showed a predominance of endosperm gluten proteins. Under scanning electron microscopy, flour particles displayed various tissue fragments with entrapped large A-starch and small B- or C-starch granules, whereas aerosol particles appeared primarily as a mixture of the endosperm intracellular interstitial protein matrix and small B- or C-starch granules free or still associated. These observations showed that aerosols supposed to penetrate deeply the airways, mainly correspond to intracellular fragments of endosperm cells enriched in gluten proteins but with lower amount of allergens belonging to albumins or globulins.

Title: Studies on aerosol properties during ICARB-2006 campaign period at Hyderabat, India using ground-based measurements and satellite data
Author: Badarinath, K. V. and Shailesh Kumar Kharol
Date of Publication: 2008
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Product: 1108

Continuous and campaign-based aerosol field measurements are essential in understanding fundamental atmospheric aerosol processes and for evaluating their effect on global climate, environment and human life. Synchronous measurements of Aerosol Optical Depth (AOD), Black Carbon (BC) aerosol mass concentration and aerosol particle size distribution were carried out during the campaign period at tropical urban regions of Hyderabad, India. Daily satellite datasets of DMSP-OLS were processed for night-time forest fires over the Indian region in order to understand the additional sources (forest fires) of aerosol. The higher values in black carbon aerosol mass concentration and aerosol optical depth correlated well with forest fires occurring over the region. Ozone Monitoring Instrument (OMI) aerosol index (AI) variations showed absorbing aerosols over the region and correlated with ground measurements.

Title: Comparison of the TSI Model 8520 and Grimm Series 1.108 Portable Aerosol Instruments Used to Monitor Particulate Matter in an Iron Foundry
Author: Yu-Hsiang Cheng
Date of Publication: 2008
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Product: 1108

This study uses two real-time dust monitors, the TSI Model 8520 DustTrak and Grimm Series 1.108 Aerosol Spectrometer, to determine PM10 and PM2.5 levels simultaneously in an iron foundry. The SA Model 241 Dichotomous Sampler was used as a reference gravimetric method for comparing the measurement results obtained by these direct-reading instruments. The response to PM levels from DustTrak is higher than that of the Aerosol Spectrometer. The DustTrak provides an overestimation PM levels, and PM levels measured by an Aerosol Spectrometer are lower than actual concentrations. Calibration factors of the DustTrak and Aerosol Spectrometer are 0.74 and 1.33, respectively, when used to measure particulate matter at an iron foundry. Based on measurement results, the DustTrak provides a lower overestimation of PM10 levels than PM2.5 levels; that is, the response of the DustTrak increases as particle size decreases. In addition, measurement results suggest that the Aerosol Spectrometer provides precise measurements of PM10 and PM2.5, and measurement accuracy compared with the reference gravimetric method can be improved through a calibration factor.

Title: Real-time measurements of fine / ultrafine sulfate aerosols in the Arctic atmosphere during summertime: Insights to Cloud Condensation Nuclei (CCN) sources
Author: Jean SCIARE, Roland Sarda-Estève
Date of Publication: 2008
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Product: 1108

Title: Inhalable and Respirable Dust
Author: Linnainmaa, Markku, Laitinen, Juha, Leskinen, Ari, Sippula, Olli and Kalliokoski, Pentti
Date of Publication: 2008
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Product: 1105

The performance of four sampling devices for inhalable dust and three devices for respirable dust was tested with different kinds of dusts in the laboratory and in the field. The IOM sampler was chosen as the reference method for inhalable dust, and the IOM sampler provided with the porous plastic foam media was used as the reference method for respirable dust. The other tested instruments were the Button sampler, the optical Grimm aerosol monitor, and the Dekati two-stage cascade impactor with cutoff sizes of 10 and 4 μm. The study confirmed the applicability of the IOM and Button samplers. The newfoam product followed the respirable criteria well. However, the foam sampler was unstable for measuring inhalable dust, probably due to its moisture absorption. In addition, high dust loads should be avoided with the foam sampler due to increase in filtering efficiency. The concentrations of inhalable dust measured with the Button sampler, the Grimm monitor, and the impactor sampler were usually close to those measured with the reference sampler. On the other hand, impactor sampling yielded higher respirable dust concentrations than the reference method in the field, which may have been caused by particle bounce; high dust loads should be avoided while using the impactor. The results also showed that the Grimm monitor enables real-time dust concentration determinations that are accurate enough for routine monitoring of occupational exposure and for testing efficiency of control measures in workplaces.

Title: Development of an Electrostatic Precipitator for Off-Line Particle Analysis
Author: J. Dixkens, H. Fissan
Date of Publication: 2008
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Product: 5561

Due to the lake of in-situ aerosol particle analysis systems, aerosol samples are taken and analyzed off-line. For detailed analysis of particle properties such as shape, morphology, and composition, off-line operating analytical tools like light microscopes, scanning electron microscopes (SEM), total reflection x-ray fluorescence (TXRF), and so on are used. The analysis must be performed on a representative sample of particles homogeneously deposited on a flat sample plate. This avoids sample preparation steps which may change the sample. In this paper we describe the design, construction, and evaluation of a continuous sampling device that deposits gasborne particles on an analytically suitable sample plate. The collection ef. ciency and the deposition pattern were optimized using a numerical model and experiments. It turned out that representative samples appropriate for further analysis can be taken in the particle size range from 0.03 m m

Title: Design and performance of an optimized electrical diffusion battery
Author:
Date of Publication: 2008
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Product: 5601

Standard aerosol instruments to measure particle size distributions in the ultrafine size range are large and heavy. We built a small electrical diffusion battery, which can be carried in a backpack and thusmakes size-resolved short-term personal aerosol exposition measurements possible. The instrument was designed for maximal measurable particle size range and long maintenance intervals. The optimum number of stages for the diffusion battery was found with a Monte-Carlo simulation. To assess the instrument's performance, we compared size distributions measured with the electrical diffusion battery to those obtained with standard aerosol instruments (the scanning mobility particle sizer and the fast mobility particle sizer of TSI Inc.). In general, the readings of the electrical diffusion battery and those of standard instruments agree well (to within 10–20%).

Title: Performance of Vienna Type Differential Mobility Analyzer at 1.2-20 Nanometer
Author: G.P.Reischel, J.M.Mäkelä,J.Necid
Date of Publication: 2008
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Product: 55

The transfer functions of the so called "Vienna type" differential mobility analyzer (DMA) were studied experimentally at the size range of 1.2-20 nm following the procedure suggested by Stolzenburg (1988) Ph.D. Thesis. For the study, two identical DMAs were used as a tandem DMA (TDMA) arrangement to measure nanoparticles from a hot wire WO, generator. The approximate analytical formulae by Stolzenburg describing diffusion broadening of the DMA transfer function were observed to be valid with high accuracy from 20 nm down to - 2 nm. In the size range of 1.2-2 nm nominal mobility equivalent diameter small deviations of the shape of the TDMA output signal predicted by Stolzenburg were found. AEROSOSLC IENCEA ND TECHNOLO2G7:6Y5 1-672 (1997) 0 1997 American Associationfor Aerosol Research

Title: Performance evaluation of three optical particle counters with an efficient multimodal calibration method
Author: Michael Heim, BenjaminJ.Mullins, Heinz Umhauer, Gerhard Kasper
Date of Publication: 2008
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Product: 1109

The sizing accuracies of two widely used yet hitherto unevaluated optical particle counters (OPCs—Grimm Model 1.109 and Palas Model WELAS 2100) as well as one high-resolution, non-commercial OPC were evaluated. The measured data were compared to scattering intensity calculations based on Mie theory. Additionally, the counting efficiency for all three counters was measured, as was the influence of coincidence effects for the OPC with the lowest (manufacturer specified) upper concentration limit. Beside the traditional polystyrene latex calibration, a little-known, very fast and precise “multimodal” calibration methodwas used, which is based on the simultaneous generation of up to eight sharpmultiple-charge modes from polydisperse di-ethyl-hexyl-sebacate (DEHS) particles by electrical mobility classification.

Title: Arctic smoke - aerosol characteristics during a record smoke event in the European Arctic and its radiative impact
Author: R. Treffeisen, P. Tunved, J. Str¨om, A. Herber; et al
Date of Publication: 2007
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Product: 1101

In early May 2006 a record high air pollution event was observed at Ny-A° lesund, Spitsbergen. An atypical weather pattern established a pathway for the rapid transport of biomass burning aerosols from agricultural fires in Eastern Europe to the Arctic. Atmospheric stability was such that the smoke was constrained to low levels, within 2 km of the surface during the transport. A description of this smoke event in terms of transport and main aerosol characteristics can be found in Stohl et al. (2007). This study puts emphasis on the radiative effect of the smoke. The aerosol number size distribution was characterised by lognormal parameters as having an accumulation mode centered around 165– 185 nm and almost 1.6 for geometric standard deviation of the mode. Nucleation and small Aitken mode particles were almost completely suppressed within the smoke plume measured at Ny-A° lesund. Chemical and microphysical aerosol information obtained at Mt. Zeppelin (474ma.s.l) was used to derive input parameters for a one-dimensional radiation transfer model to explore the radiative effects of the smoke. The daily mean heating rate calculated on 2 May 2006 for the average size distribution and measured chemical composition reached 0.55Kday^−1 at 0.5 km altitude for the assumed external mixture of the aerosols but showing much higher heating rates for an internal mixture (1.7Kday^−1). In comparison a case study for March 2000 showed that the local climatic effects due to Arctic haze, using a regional climate model, HIRHAM, amounts to a maximum of 0.3Kday^−1 of heating at 2 km altitude (Treffeisen et al., 2005).

Title: Challenge testing in the diagnosis of occupational allergic conjunctivitis
Author: Tomasz Wittczak1,2, Anna Krakowiak1,2, Jolanta Walusiak1,2, Alicja Pas-Wyroslak3, Monika Kowalczyk1,2 and Cezary Palczynski1,2,4
Date of Publication: 2007
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Product: 1105

To perform cellular analysis of tear fluid before and after a specific challenge test with high-molecular weight allergens in symptomatic subjects.

Title: Sources, size distribution, and downwind grounding of aerosols from Mount Etna
Author: A. G. Allen,1 T. A. Mather,2 A. J. S. McGonigle,3 A. Aiuppa,4 P. Delmelle,et al
Date of Publication: 2006
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Product: 1108

The number concentrations and size distributions of aerosol particles >0.3 μm diameter were measured at the summit of Mount Etna and up to 10 km downwind from the degassing vents during July and August 2004. Aerosol number concentrations reached in excess of 9 × 106 L−1 at summit vents, compared to 4–8 × 104 L−1 in background air. Number concentrations of intermediate size particles were higher in emissions from the Northeast crater compared to other summit crater vents, and chemical composition measurements showed that Northeast crater aerosols contained a higher mineral cation content compared to those from Voragine or Bocca Nuova, attributed to Strombolian or gas puffing activity within the vent. Downwind from the summit the airborne plume was located using zenith sky ultraviolet spectroscopy. Simultaneous measurements indicated a coincidence of elevated ground level aerosol concentrations with overhead SO2, demonstrating rapid downward mixing of the plume onto the lower flanks of the volcano under certain meteorological conditions. At downwind sites the ground level particle number concentrations were elevated in all size fractions, notably in the 2.0–7.5 μm size range. These findings are relevant for assessing human health hazard and suggest that aerosol size distribution measurements may aid volcanic risk management.

Title: Evaluation of a High-Efficiency, Filter-Bank System
Author: Stephen B. Martin Jr., Bryan R. Beamer, and Ernest S. Moyer
Date of Publication: 2006
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Product: 1108

National Institute for Occupational Safety and Health (NIOSH) investigators evaluated filtration efficiencies at three U.S. Postal Service (USPS) facilities. Ventilation and filtration systems (VFSs) had been installed after the 2001 bioterrorist attacks when the USPS unknowingly processed letters laden with B. anthracis spores. The new VFS units included high-efficiency particulate air (HEPA) filters and were required by USPS contract specifications to provide an overall filtration efficiency of at least 99.97% for particles between 0.3 μm and 3.0 μ m. The USPS evaluation involved a modification of methodology used to test total filtration system efficiency in agricultural tractor cab enclosures. The modified sampling strategy not only proved effective for monitoring the total filtration system component of VFS performance but also distinguished between filtration systems performing to the high USPS performance criteria and those needing repair or replacement. The results clearly showed the importance of choosing a pair of optical particle counters that have been closely matched immediately prior to testing. The modified methodology is readily adaptable to any workplace wishing to evaluate air filtration systems, including high-efficiency systems.

Title: Penetration of Ultrafine Particles and Ion Clusters Through Wire Screens by Ichitsubo et al.
Author: M. Heim, B. J. Mullins, and G. Kasper
Date of Publication: 2006
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Product: 55

A recent paper by the authors (Heim et al. 2005) examined the filtration efficiency of nanoparticles in the 2.5–20 nm size range, in an attempt to determine if thermal bounce occurs. The work included a critical review of previous work, including the work of Ichitsubo et al. (1996), which was the only paper found by the authors which appeared to detect actual “thermal rebound.”

Title: Experimental study on enhanced Brownian coagulation of sodium compound aerosol in the presence of gamma field
Author: V. Subramaniana, R. Baskarana,∗, R. Indiraa
Date of Publication: 2005
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Product: 1108

In this study experiments were carried out by generating sodium compound aerosols in the aerosol test facility (ATF) and exposing the chamber volume panoramically with gamma radiation source. By using a light scattering technique, the real time changes in number concentration of aerosols and their volume–size distributions were measured. From the data, the coagulation coefficient is derived with and without the presence of gamma radiation field. It is observed that the coagulation coefficient is nearly one order more in the presence of gamma field than without gamma field. From the volume–size distribution data, it is observed that when there is no gamma field, there is a gradual shifting of mode from lower size to upper size ranges during the period of 100 min whereas, when gamma field is present, the size distribution becomes bi-modal at about 5 min duration and becomes multimodal as time progresses.

Title: Occupational eosinophilic bronchitis in afoundry worker exposed to iscyanate and baker exposed to flou
Author: abio Di Stefano, Luca Di Giampaolo, Nicola Verna and Mario Di Gioacchino
Date of Publication: 2005
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Eosinophilic bronchitis without asthma may occur as a consequence of occupational exposure. The cases of a foundry worker and a baker who developed symptoms, respectively, due to exposure to isocyanate and flour, are reported. Cough was not associated with variable airflow obstruction or with airway hyper-responsiveness and was responsive to inhaled corticosteroids. The eosinophilia detectable in their sputum was causally related to the occupational exposure in the workplace. The examination of induced sputum should be used in addition to the objective monitoring of lung function for workers who have asthma-like symptoms in an occupational setting.

Title: Measurements of atmospheric aerosol size distributions by co-located optical particle counters
Author: A. Tiwary, J. Colls
Date of Publication: 2004
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Product: 1105

Ambient aerosol number concentrations and size distributions were measured in both indoor and outdoor environments using two identical co-located and concurrently operated optical particle counters (OPCs). Indoor measurements were performed in a research laboratory, whereas two different locations were used for outdoor measurements; the sampling duration exceeded 12 hours and one hour respectively. Results from the two OPCs have been presented for eight size classes between 0.5 and 20 mm, represented by central value diameters 0.875, 1.5, 2.75, 4.25, 6.25, 8.75, 12.5 and 15 mm. Overall, for the six indoor and outdoor experiments conducted at different times of day, the mean particle count ratios from the two OPCs for the individual samples showed ¡20% variation for indoor experiments and ¡50% variations for outdoor experiments. Significant random departures of the mean ratios from unity at all size classes were noticed even for indoor sample periods exceeding 20 hours. However, the coefficient of determination (R2) for the plots of readings from the two OPCs indicated higher consistency for ‘‘fine’’ particles (0.5–3.5 mm) than for ‘‘coarse’’ particles (10–20 mm), with average R2 w 0.8 and R2 v 0.5 respectively. Poisson counting statistics help to explain the divergence in the latter case where number concentrations were very low for the outdoor experiments. However, it cannot explain the divergence for indoor measurements where the concentrations were much higher. Increasing the averaging period reduced the scatter, especially in size classes with low number concentration. However, this procedure may lead to over-smoothing of data for environments with rapidly changing number concentration. These results indicate that, when two such analysers are used for comparative studies, the divergence between their responses may generate significant values of source contribution or deposition flux, even for nominally similar aerosol populations.

Title: Size-segregated aerosol mass closure and chemical composition in Monte Cimone (I) during MINATROC
Author: J.-P. Putaud1, R. Van Dingenen1, A. Dell’Acqua1, et al
Date of Publication: 2004
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Product: 1105

Physical and chemical characterizations of the atmospheric aerosol were carried out at Mt. Cimone (Italy) during the 4 June–4 July 2000 period. Particle size distributions in the size range 6 nm–10μm were measured with a differential mobility analyzer (DMA) and an optical particle counter (OPC). Size-segregated aerosol was sampled using a 6-stage low pressure impactor. Aerosol samples were submitted to gravimetric and chemical analyses. Ionic, carbonaceous and refractory components of the aerosol were quantified. We compared the sub- and super-μm aerosol mass concentrations determined by gravimetric measurements (mGM), chemical analyses (mCA), and by converting particle size distribution to aerosol mass concentrations (mSD). Mean random uncertainties associated with the determination of mGM, mCA, and mSD were assessed. The three estimates of the sub-μm aerosol mass concentration agreed, which shows that within experimental uncertainty, the sub-μm aerosol was composed of the quantified components. The three estimates of the super-μm aerosol mass concentration did not agree, which indicates that random uncertainties and/or possible systematic errors in aerosol sampling, sizing or analyses were not adequately accounted for. Aerosol chemical composition in air masses from different origins showed differences, which were significant in regard to experimental uncertainties. During the Saharan dust advection period, coarse dust and fine anthropogenic particles were externally mixed. No anthropogenic sulfate could be found in the super-μm dust particles. In contrast, nitrate was shifted towards the aerosol super-μm fraction in presence of desert dust.

Title: Size-segregated aerosol mass closure and chemical composition in Monte Cimone (I) during MINATROC
Author: J.-P. Putaud1, R. Van Dingenen1, A. Dell’Acqua1, et al
Date of Publication: 2004
Hyperlink: Link
Product: 1105

Physical and chemical characterizations of the atmospheric aerosol were carried out at Mt. Cimone (Italy) during the 4 June–4 July 2000 period. Particle size distributions in the size range 6 nm–10μm were measured with a differential mobility analyzer (DMA) and an optical particle counter (OPC). Size-segregated aerosol was sampled using a 6-stage low pressure impactor. Aerosol samples were submitted to gravimetric and chemical analyses. Ionic, carbonaceous and refractory components of the aerosol were quantified. We compared the sub- and super-μm aerosol mass concentrations determined by gravimetric measurements (mGM), chemical analyses (mCA), and by converting particle size distribution to aerosol mass concentrations (mSD). Mean random uncertainties associated with the determination of mGM, mCA, and mSD were assessed. The three estimates of the sub-μm aerosol mass concentration agreed, which shows that within experimental uncertainty, the sub-μm aerosol was composed of the quantified components. The three estimates of the super-μm aerosol mass concentration did not agree, which indicates that random uncertainties and/or possible systematic errors in aerosol sampling, sizing or analyses were not adequately accounted for. Aerosol chemical composition in air masses from different origins showed differences, which were significant in regard to experimental uncertainties. During the Saharan dust advection period, coarse dust and fine anthropogenic particles were externally mixed. No anthropogenic sulfate could be found in the super-μm dust particles. In contrast, nitrate was shifted towards the aerosol super-μm fraction in presence of desert dust.

Title: Filamentous Microorganisms and their fragments in indoor air
Author: Rafal L, Gorny
Date of Publication: 2004
Hyperlink: Link
Product: 1109

The paper summarizes the current state of knowledge regarding the role of filamentous microorganisms (i.e., fungi and actinomycetes) and their submicrometerpropagules (fragments) in formation of indoor bioaerosol. It discusses the importance of water damages in buildings and the role of humidity as a cause of fungal andactinomycetal contamination and subsequent deterioration of indoor spaces. The importance of the size of airborne microbial propagules for adverse health effects is broadly commented as well. Regarding the microbial fragments, the method of their release from the contaminated surfaces (including factors influencing their aerosolization, i.e., air velocity, colony structure, moisture conditions, vibration of the surface, time factor), modern measurement techniques and newly obtained results of the immunological reactivity of fragments are discussed. The novel ideas concerning the dynamic description of the release process of microbial propagules from their sources are also presented.

Title: Bestimmung diffuser Emissionen in einem Asphaltmischwerk
Author: Dipl.- Chem. J. Krusche, Dipl.- Ing. R. Heidenreich, Dipl.- Ing. A. Zschoppe
Date of Publication: 2003
Hyperlink:
Product: 1106

Im Auftrag des Sächsischen Landesamtes für Umwelt und Geologie wurde eine Messeinrichtung zur Bestimmung der diffusen Emissionen für den Industriezweig Steine/ Erden entwickelt und erprobt. Die Erstmessung wurde an einer Asphaltmischanlage (AMA) durchgeführt. Die neue Messmethode zur Charakterisierung diffuser Emissionen erfasst sowohl die Staubkonzentration, als auch die Kornverteilung des Staubes an verschiedenen Punkten einer flächenhaften Emission. Die Erprobung der Messeinrichtung konnte erfolgreich durchgeführt werden. Die in vier Messkampagnen an dem Asphaltmischplatz Freital der Sächsischen Asphaltmischwerke gewonnenen Erkenntnisse erlauben es, die Gesamtemission des Mischplatzes und ihren Einfluss auf die Umgebung besser als bisher einzuschätzen.

Title: Evaluation of Aerosol Release During the Handling of Unrefined Single Walled Carbon Nanotube Material
Author: National Institute for Occupational Safety and Health, 4676 Columbia Parkway, Cincinnati, OH 45226; †Comprehensive Health Services, Inc., NASA-JSCPaul A Baron, Andrew D Maynard, and Michael Foley
Date of Publication: 2003
Hyperlink: Link
Product: 1108

Carbon nanotubes represent a new form of carbon that has several unique properties, including great tensile strength, high conductivity (in some states), high surface area, unique electronic properties, and potentially high molecular adsorption capacity. A number of laboratories are generating small quantities of this material, and commercial interest in the substance is motivating the rapid development of large-scale production facilities. However, little is known of the potential toxicity of the material, or how it should most appropriately be handled to minimize exposure.
In a collaborative effort the National Institute for Occupational Safety and Health (NIOSH), National Aeronautics and Space Administration (NASA), Rice University, and Carbon Nanotechnologies Inc. (CNI) are investigating the nature of the aerosol released when unrefined nanotubes are handled—that is, the material that is aerosolized during the production process, prior to its being purified. Two separate studies have been undertaken on single-walled carbon
nanotubes (SWCNT)—a specific form of the material comprised of carbon tubes around 1.5 nanometers (nm) in diameter and up to a millimeter or more in length, and having a single layer of carbon atoms that form the tube wall. Two sources of the material were considered: (1) laser ablation, which leads to a relatively compact powder, and (2) nanotubes formed using the High-Pressure Carbon Monoxide process (HiPCO®), leading to an expanded material that has very low bulk density. Primarily, the propensity for the material to form an aerosol while being agitated was investigated in the laboratory. Aerosol size distribution between 4 nm and 20 μm was measured when the material was agitated in a number of ways. At high agitation levels, a bimodal or trimodal aerosol was formed below 10 μm, depending on the material source, and HiPCO®-generated material led to the release of particles smaller than 10 nm in diameter. However, it was unclear whether these particles represented nanotubes, catalyst particles (used in the manufacturing process), or compact
carbonaceous particles. Generation rates were typically two orders of magnitude below those for a similar volume of fumed alumina—chosen because it represents another material that has a very low bulk density and is formed from nanometer-sized primary particles. ...

Title: Measuring the Emission Rate of an Aerosol Source Placed in a Ventilated Room Using Tracer Gas: Influence of Particle Wall Deposition
Author: D. BÉMER, M. T. LECLER, R. RÉGNIER, G. HECHT, J. M. GERBER
Date of Publication: 2001
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Product: 1108

A method to measure the emission rate of an airborne pollutant source using a tracer gas was tested in the case of an aerosol source. The influence of particle deposition on the walls of a test room of 72 m3 was studied. The deposition rate of an aerosol of MgCl2 was determined by means of two methods: one based on measuring the aerosol concentration decay inside the ventilated room, the other based on calculation of the material mass balance. The concentration decay was monitored by optical counting and the aerosol mass concentration determined by means of sampling on a filter and analysis of the mass deposited by atomic absorption spectrometry. Four series of measurements were carried out. The curve giving the deposition rate according to the particle aerodynamic diameter (dae) was established and shows deposition rates higher than those predicted using the model of Corner. The decay method gives the best results. The study carried out has shown that the phenomenon of deposition has little effect on the measurement of the aerosol source emission rate using a tracer gas for particles of aerodynamic diameter <5 µm (underestimation <25%). For particles of a greater diameter, wall deposition is an extremely limiting factor for the method, the influence of which can, however, be limited by using a test booth of small volume and keeping the sampling duration as short as possible.

Title: Physical characterization of particulate emissions from diesel engines: a review
Author: H. Burtscher
Date of Publication: 1999
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Product: 55

Properties of particles emitted from diesel engines and the consequences of these properties for sampling and measuring the particles are reviewed. The influence of aftertreatment devices such as particle traps and catalytic converters on particle properties is demonstrated. Based on the particle properties and results from health effect studies, requirements to metrics, and measurement systems, for example, for type approval testing, are discussed. This discussion is limited to physical properties. Special attention is given to the volatile fraction. We show that care has to be taken when designing the sampling and dilution system, because this step decisively influences what happens with the volatile material, which may remain in the gas phase, condense on solid particles, or form new particles by nucleation. If nucleation occurs, particles formed in the sampling lines may dominate the particle number concentration. A selection of systems for dilution, conditioning and measuring is shown. Systems to determine number, mass, and surface concentrations, size distributions, and carbon concentration are discussed. The discussion is focused on systems developed or adapted recently for the physical characterization of diesel particles. 2005 Elsevier Ltd. All rights reserved.

Title: A new Electromobility Spectrometer for the Measurement of aerosol distributions in the Sizerange from 1 to 1000nm
Author: W.Winklmayr, G.P. Reischl, O.Lindner, A.Berner
Date of Publication: 1990
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Product: 55-U

The electromobility Spectrometer is an automated measurement system for the size analysis if fine and ultrafine aerosols using Differential Mobility Analysers (DMA) for the classification of particles and an elestrical sensor for their detection. To cover a particle sizerange from 1 to 1000nm, new DMAs with different geometries have been designed to optimize performance for small and large particles. Key problems in the characterization of partices smaller than 20nm have been adressed. A Farady Cup electrometer woth a sensitivity of 10^-16 A is used as a particle sensor to avoid the deficieny of condensation nucleus counters with counting efficiencies decreasing with particle size...


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