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Wiedensohler A.,Leibniz Institute for Tropospheric Research | Birmili W.,Leibniz Institute for Tropospheric Research | Nowak A.,Leibniz Institute for Tropospheric Research | Sonntag A.,Leibniz Institute for Tropospheric Research | And 47 more authors.
Atmospheric Measurement Techniques | Year: 2012

Mobility particle size spectrometers often referred to as DMPS (Differential Mobility Particle Sizers) or SMPS (Scanning Mobility Particle Sizers) have found a wide range of applications in atmospheric aerosol research. However, comparability of measurements conducted world-wide is hampered by lack of generally accepted technical standards and guidelines with respect to the instrumental set-up, measurement mode, data evaluation as well as quality control. Technical standards were developed for a minimum requirement of mobility size spectrometry to perform long-term atmospheric aerosol measurements. Technical recommendations include continuous monitoring of flow rates, temperature, pressure, and relative humidity for the sheath and sample air in the differential mobility analyzer. We compared commercial and custom-made inversion routines to calculate the particle number size distributions from the measured electrical mobility distribution. All inversion routines are comparable within few per cent uncertainty for a given set of raw data. Furthermore, this work summarizes the results from several instrument intercomparison workshops conducted within the European infrastructure project EUSAAR (European Supersites for Atmospheric Aerosol Research) and ACTRIS (Aerosols, Clouds, and Trace gases Research InfraStructure Network) to determine present uncertainties especially of custom-built mobility particle size spectrometers. Under controlled laboratory conditions, the particle number size distributions from 20 to 200 nm determined by mobility particle size spectrometers of different design are within an uncertainty range of around ±10% after correcting internal particle losses, while below and above this size range the discrepancies increased. For particles larger than 200 nm, the uncertainty range increased to 30%, which could not be explained. The network reference mobility spectrometers with identical design agreed within ±4% in the peak particle number concentration when all settings were done carefully. The consistency of these reference instruments to the total particle number concentration was demonstrated to be less than 5%. Additionally, a new data structure for particle number size distributions was introduced to store and disseminate the data at EMEP (European Monitoring and Evaluation Program). This structure contains three levels: raw data, processed data, and final particle size distributions. Importantly, we recommend reporting raw measurements including all relevant instrument parameters as well as a complete documentation on all data transformation and correction steps. These technical and data structure standards aim to enhance the quality of long-term size distribution measurements, their comparability between different networks and sites, and their transparency and traceability back to raw data. © Author(s) 2012. Source

Stoehr L.C.,GRIMM Aerosol Technik GmbH and Co. KG | Stoehr L.C.,University of Salzburg | Madl P.,University of Salzburg | Boyles M.S.P.,University of Salzburg | And 9 more authors.
Environmental Science and Technology | Year: 2015

Air pollution is associated with increased risk of cardiovascular and pulmonary diseases, but conventional air quality monitoring gives no information about biological consequences. Exposing human lung cells at the air-liquid interface (ALI) to ambient aerosol could help identify acute biological responses. This study investigated electrode-assisted deposition of diesel exhaust aerosol (DEA) on human lung epithelial cells (A549) in a prototype exposure chamber. A549 cells were exposed to DEA at the ALI and under submerged conditions in different electrostatic fields (EFs) and were assessed for cell viability, membrane integrity, and IL-8 secretion. Qualitative differences of the DEA and its deposition under different EFs were characterized using scanning mobility particle sizer (SMPS) measurements, transmission electron microscopy (TEM), and electron energy loss spectroscopy (EELS). Upon exposure to DEA only, cell viability decreased and membrane impairment increased for cells at the ALI; submerged cells were unaffected. These responses were enhanced upon application of an EF, as was DEA deposition. No adverse effects were observed for filtered DEA or air only, confirming particle-induced responses. The prototype exposure chamber proved suitable for testing DEA-induced biological responses of cells at the ALI using electrode-assisted deposition and may be useful for analysis of other air pollutants. © 2015 American Chemical Society. Source

Stoehr L.C.,University of Salzburg | Stoehr L.C.,GRIMM Aerosol Technik GmbH and Co. KG | Endes C.,University of Fribourg | Radauer-Preiml I.,University of Salzburg | And 9 more authors.
Particle and Fibre Toxicology | Year: 2015

Background: Stably transfected lung epithelial reporter cell lines pose an advantageous alternative to replace complex experimental techniques to monitor the pro-inflammatory response following nanoparticle (NP) exposure. Previously, reporter cell lines have been used under submerged culture conditions, however, their potential usefulness in combination with air-liquid interface (ALI) exposures is currently unknown. Therefore, the aim of the present study was to compare a panel of interleukin-8 promoter (pIL8)-reporter cell lines (i.e. green or red fluorescent protein (GFP, RFP), and luciferase (Luc)), originating from A549 lung epithelial type II-like cells cells, following NPs exposure under both submerged and ALI conditions. Methods: All cell lines were exposed to zinc oxide (ZnO) NPs at 0.6 and 6.2 μg/cm2 for 3 and 16 hours under both submerged and ALI conditions. Following physicochemical characterization, the cytotoxic profile of the ZnO-NPs was determined for each exposure scenario. Expression of IL-8 from all cell types was analyzed at the promoter level and compared to the mRNA (qRT-PCR) and protein level (ELISA). Results: In summary, each reporter cell line detected acute pro-inflammatory effects following ZnO exposure under each condition tested. The pIL8-Luc cell line was the most sensitive in terms of reporter signal strength and onset velocity following TNF-aα treatment. Both pIL8-GFP and pIL8-RFP also showed a marked signal induction in response to TNF-aα, although only after 16 hrs. In terms of ZnO-NP-induced cytotoxicity pIL8-RFP cells were the most affected, whilst the pIL8-Luc were found the least responsive. Conclusions: In conclusion, the use of fluorescence-based reporter cell lines can provide a useful tool in screening the pro-inflammatory response following NP exposure in both submerged and ALI cell cultures. © 2015 Stoehr et al. Source

Schneider F.,GRIMM Aerosol Technik GmbH and Co. KG | Spielvogel J.,GRIMM Aerosol Technik GmbH and Co. KG | Hock T.,Hagenlocher GmbH and Co. KG | Pesch M.,GRIMM Aerosol Technik GmbH and Co. KG
Chemical Engineering Transactions | Year: 2010

A 15 kW test pellet burner was evaluated in regards to particle emission in preparation of an upcoming change in regulation. If the burner was operated incorrectly significant levels of particle emission were reached. The GRIMM emission sampling system in combination with a scanning mobility particle sizer allowed continuous online measurements of these emissions in the size range 3nm to 155nm with a resolution of 44 size channels. Single channel measurements can be performed with a time resolution of up to 4 Hz. The system is very robust, portable, and only needs a power outlet for operation, it is therefore ideal for process control and emission measurements. Copyright © 2010, AIDIC Servizi S.r.l. Source

Keck L.,GRIMM Aerosol Technik GmbH and Co. KG | Pesch M.,GRIMM Aerosol Technik GmbH and Co. KG | Grimm H.,GRIMM Aerosol Technik GmbH and Co. KG
Journal of Physics: Conference Series | Year: 2011

A wide range aerosol spectrometer (WRAS) was used for comprehensive long term measurements of aerosol size distributions. The system combines the results of an optical aerosol spectrometer with the results of a Scanning Mobility Particle Sizer (SMPS) to record essentially the full size range (5 nm - 32 μm) of atmospheric particles in 72 channels. Measurements were carried out over one year (2009) at the Global Atmospheric Watch (GAW)-Station Hohenpeienberg, Bavaria. Total particle number concentrations obtained from the aerosol size distributions were compared to the total number concentrations measured by a Condensation Particle Counter (CPC). The comparison showed an excellent agreement of the data. The high time resolution of 5 minutes allows the combination of the measured size distributions with meteorological data and correlations to gaseous pollutants (CO, NOx and SO2). A good correlation of particle number and CO concentrations was found for long distance transported small particles, which were probably mainly soot particles. Correlations to NOx were observed for aerosols from local sources such as traffic emissions. The formation of secondary aerosols from gaseous precursors was also observed. Episodes of relatively high concentration of particles in the range of 2-3 μm were probably caused by pollen. Source

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