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Schulte P.A.,Centers for Disease Control and Prevention | Iavicoli I.,University of Naples Federico II | Rantanen J.H.,International Commission on Occupational Health ICOH | Dahmann D.,Institute for the Research on Hazardous Substances IGF | And 9 more authors.
Nanotoxicology | Year: 2016

Responsible development of any technology, including nanotechnology, requires protecting workers, the first people to be exposed to the products of the technology. In the case of nanotechnology, this is difficult to achieve because in spite of early evidence raising health and safety concerns, there are uncertainties about hazards and risks. The global response to these concerns has been the issuance by authoritative agencies of precautionary guidance to strictly control exposures to engineered nanomaterials (ENMs). This commentary summarizes discussions at the “Symposium on the Health Protection of Nanomaterial Workers” held in Rome (25 and 26 February 2015). There scientists and practitioners from 11 countries took stock of what is known about hazards and risks resulting from exposure to ENMs, confirmed that uncertainties still exist, and deliberated on what it would take to conduct a global assessment of how well workers are being protected from potentially harmful exposures. © 2016 Taylor & Francis.

Fonseca A.S.,CSIC - Institute of Environmental Assessment And Water Research | Fonseca A.S.,University of Barcelona | Viana M.,CSIC - Institute of Environmental Assessment And Water Research | Perez N.,CSIC - Institute of Environmental Assessment And Water Research | And 6 more authors.
Aerosol Science and Technology | Year: 2016

ABSTRACT: During occupational exposure studies, the use of conventional scanning mobility particle sizers (SMPS) provides high quality data but may convey transport and application limitations. New instruments aiming to overcome these limitations are being currently developed. The purpose of the present study was to compare the performance of the novel portable NanoScan SMPS TSI 3910 with that of two stationary SMPS instruments and one ultrafine condensation particle counter (UCPC) in a controlled atmosphere and for different particle types and concentrations. The results show that NanoScan tends to overestimate particle number concentrations with regard to the UCPC, particularly for agglomerated particles (ZnO, spark generated soot and diesel soot particles) with relative differences >20%. The best agreements between the internal reference values and measured number concentrations were obtained when measuring compact and spherical particles (NaCl and DEHS particles). With regard to particle diameter (modal size), results from NanoScan were comparable < [± 20%] to those measured by SMPSs for most of the aerosols measured. The findings of this study show that mobility particle sizers using unipolar and bipolar charging may be affected differently by particle size, morphologies, particle composition and concentration. While the sizing accuracy of the NanoScan SMPS was mostly within ±25%, it may miscount total particle number concentration by more than 50% (especially for agglomerated particles), thus making it unsuitable for occupational exposure assessments where high degree of accuracy is required (e.g., in tier 3). However, can be a useful instrument to obtain an estimate of the aerosol size distribution in indoor and workplace air, e.g., in tier 2. © 2016 Spanish Research Council. Published with liscence by American Assotiation for Aerosol Research.

Weber K.,Dusseldorf University of Applied Sciences | Eliasson J.,University of Iceland | Vogel A.,Dusseldorf University of Applied Sciences | Fischer C.,Dusseldorf University of Applied Sciences | And 5 more authors.
Atmospheric Environment | Year: 2012

During the time period of the eruption of the Icelandic volcano Eyjafjallajökull in April/May 2010 the Duesseldorf University of Applied Sciences has performed 14 research flights in situations with and without the volcanic ash plume over Germany. In parallel to the research flights in Germany three measurement flights have been performed by the University of Iceland in May 2010 over the western part of Iceland. During two of these flights the outskirts of the eruption plume were entered directly, delivering most direct measurements within the eruption plume during this eruptive event. For all the measurement flights reported here, light durable piston-motor driven aircrafts were used, which were equipped with optical particle counters for in-situ measurements. Real-time monitoring of the particle concentrations was possible during the flights. As different types of optical particle counters have been used in Iceland and Germany, the optical particle counters have been re-calibrated after the flights to the same standard using gravimetric reference methods and original Eyjafjallajökull volcanic ash samples. In-situ measurement results with high spatial resolution, directly from the eruption plume in Iceland as well as from the dispersed and several days old plume over Germany, are therefore presented here for the first time. They are normalized to the same ash concentration calibration standard. Moreover, airborne particles could be sampled directly out of the eruption plume in Iceland as well as during the flights over Germany.During the research flights over Iceland from 9 May 2011 to 11 May 2011 the ash emitted from the vent of the volcano turned out to be concentrated in a narrow well-defined plume of about 10km width at a distance of 45-60km away from the vent. Outside this plume the airborne ash concentrations could be proved to be below 50μgm -3 over western Iceland. However, by entering the outskirts of the plume directly the research aircraft could detect ash concentrations of up to 2000μgm -3.On the other hand, the ash plume, which was analysed by research flights over Germany several thousand km away from the eruption vent, appeared to be significantly structured in horizontal and vertical directions. Different sub-plumes could be found. Peak concentrations of more than 330μg m -3 could be detected.The results of the measurements within the ash plume over Germany were compared with the predictions of the London VAAC model. The range of ash concentrations found by the research aircraft in Germany were not in conflict with the calculations of concentration regimes by the London VAAC model. However, the in-situ measurements performed by the research aircraft were able to deliver information about the structure and composition of the ash plume, which could not be covered by the dispersion model.Therefore, light piston-motor driven aircrafts equipped with optical particle counters proved to be a very versatile tool for the real-time in-situ determination of the spatial extension of volcanic ash plumes, the ash particle size distributions and the particle mass concentrations. Moreover, all these parameters could be measured with a high horizontal and vertical spatial resolution. Therefore, these kinds of measurements can deliver immediate data for the validation and verification of dispersion models and can give direct in-situ information additional to LIDAR measurements and satellite observations. As the piston-motor driven aircrafts are able to operate even at elevated volcanic ash concentrations they can provide valuable ash concentration results for air traffic safety. © 2011 Elsevier Ltd.

Grafen M.,Ruhr University Bochum | Nalpantidis K.,Ruhr University Bochum | Platte F.,Ruhr University Bochum | Monz C.,Institute for the Research on Hazardous Substances IGF | Ostendorf A.,Ruhr University Bochum
Aerosol Science and Technology | Year: 2015

The demand for precise and continuous monitoring of air quality has increased. An important descriptor of air quality is the concentration of problematic carbonaceous particles responsible for diseases and climate change. The specific measurement of carbonaceous components in the air is still a topic in research and development. Here, we introduce an integrated and continuous soot monitoring system based on Raman spectroscopy. In comparison to the often utilized light absorption, Raman spectroscopy is capable of determining the graphitic microstructure found in carbonaceous particles. We present first measurements taken in a controlled environment contaminated with varying concentrations of diesel soot. The Raman bands of soot turn out to be tightly mixed up with signals from secondary physical factors. In order to evaluate the data, multivariate methods are applied. After determination of the latent variables using principal component analysis (PCA), the system is further rotated using a linear discriminant analysis (LDA)-criterion and a subsequent nonlinear iterative partial least squares (NIPALS)-like step. One of the variables obtained by this methodology can be shown to exclusively describe the optical filter loading while the orthogonal factor space allows for conclusions on the secondary factors.Copyright 2015 American Association for Aerosol Research © 2015 Copyright © American Association for Aerosol Research.

Asbach C.,Institute of Energy and Environmental Technology | Kaminski H.,Institute of Energy and Environmental Technology | Von Barany D.,Institute of Energy and Environmental Technology | Kuhlbusch T.A.J.,Institute of Energy and Environmental Technology | And 9 more authors.
Annals of Occupational Hygiene | Year: 2012

Five different portable instrument types to monitor exposure to nanoparticles were subject to an intensive intercomparison measurement campaign. Four of them were based on electrical diffusion charging to determine the number concentration or lung deposited surface area (LDSA) concentration of airborne particles. Three out of these four also determined the mean particle size. The fifth instrument type was a handheld condensation particle counter (CPC). The instruments were challenged with three different log-normally distributed test aerosols with modal diameters between 30 and 180 nm, varying in particle concentration and morphology. The CPCs showed the highest comparability with deviations on the order of only ±5%, independent of the particle sizes, but with a strictly limited upper number concentration. The diffusion chargerbased instruments showed comparability on the order of ±30% for number concentration, LDSA concentration, and mean particle size, when the specified particle size range of the instruments matched the size range of the aerosol particles, whereas significant deviations were found when a large amount of particles exceeded the upper or lower detection limit. In one case the reported number concentration was even increased by a factor of 6.9 when the modal diameter of the test aerosol exceeded the specified upper limit of the instrument. A general dependence of the measurement accuracy of all devices on particle morphology was not detected. © The Author 2012.

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