Suchergebnisse

The mechanisms by which mineral dusts cause cell damage and altered proliferation and/or differentiation of cells are presented in "state-of-the-art" reviews of clinical and basic research. Sessions-in-depth include: Physicochemical properties of dusts as related to their pathogenic potential; molecular biology and oncogenes; growth factors and mechanisms of proliferation; mechanisms of inflammation; involvement of active oxygen species, etc. This comprehensive treatment shows how fibers and particulates cause cell damage, inflammation and disturbancies in growth, and allows us to understand the mechanisms of dust-induced lung disease

This work evaluates the potential of use of mineral dust waste from stone extraction and processing industries to develop composite materials to construction sector. Actually, a high volume of mineral waste was generated, in a stone extraction and processing industries, without any type of recycling and recovery. In this work, this waste was combined with a biopolymeric material, with different mass ratios, namely 70:30 and 50:50 of mineral waste and polymeric material. To accelerate the curing process, a compression moulding process was used. After that, a several characterization tests were performed, in order to compare the main properties of the composite materials obtained with different mass ratios of mineral dust and polymeric material. The physical and mechanical tests were performed to evaluate the density, moisture absorption, flexural strength and flexural modulus. Besides that, the thermal properties were obtained using an Alambeta testing device. The experimental results show a decrease of density of the composite materials from 2.7 g cm-3 to 2.03 g cm-3, compared with virgin slate rock. In terms of mechanical performance, an increase of flexural strength from 17.1 MPa to approximately 80 MPa was verified between Viroc and the composite materials obtained. In addition to this, an HB rating on flammability test guarantees to the composite materials an excellent capacity to fire resistance. These results allow to conclude that the recycling and recovery the slate waste has a big potential of application in several areas, such as construction one. ; project "Fibrenamics Green -Platform for the development of innovative waste -based products", code NORTE-01-0246-FEDER-000008, which is co-financed by the European Union, through the European Regional Development Fund (ERDF) under the NORTE 2020 -North Portugal Regional Operational Program 2014 –2020 ...

The role played by aerosols on UV radiative transfer in the atmosphere is very uncertain. This is especially true regarding mineral dust. To determine the sensitivity of the UV levels to the presence of this atmospheric specie, we have simulated the UV irradiance with different vertical distributions of mineral dust. We have used a discrete ordinates radiative transfer model to obtain the UV levels both at sea level and at 3000 m. We have computed the aerosol single-scattering albedo, the phase function, and the asymmetry factor by Mie scattering theory. The background aerosol profiles were taken from WCRP [1986] models, whereas the radiative properties of mineral dust have been calculated from the aerosol size distribution obtained during Saharan dust invasions at Tenerife island (28.5°N, 16.3°W). The values for aerosol optical depth assumed as input for the model calculations are 0.2 (at 550 nm) for clean background aerosols and 0.3 (at 550 nm) for the mineral dust component. From the results we can conclude that the dust vertical size distribution can affect the irradiance ratio F (with Saharan dust)/F (no Saharan dust) by 2–4%. In addition, we observe that to the same total optical depth the diffuse UV levels depend not only on the vertical dust distribution but also on the background aerosol vertical distribution. We have computed differences for the diffuse radiation fluxes of about 5% between a maritime and a continental model to the same mineral dust vertical distribution. ; This work has been supported by the CICYT (Comisión Interministerial de Ciencia y Tecnologia- Spanish Government) under contract CLI97-0453 and the Gobierno Autónomo de Canarias by contract 4/95.

This paper presents a new empirical equation relating horizontal visibility and PM10 dust concentrations. The new empirical equation (IZO-Eq) is derived from observations performed at the Izaña Atmospheric Observatory (IZO, 28.30ºN, 16.49ºW, 2367 m a.s.l., Tenerife, Spain), recorded during Saharan dust outbreaks from 2003 to 2010. A filter based on relative humidity, present-weather and aerosol optical properties is applied to identify dust events. IZO-Eq is validated in the Sahel region during the dry and wet seasons (2006-2008) using data from two PM10 monitoring stations from the African Monsoon Multidisciplinary Analysis (AMMA) International project, and data from the nearest meteorological synoptic stations. The estimated PM10 derived from IZO-Eq is compared against that those obtained by other empirical equations and dust surface concentrations from NMMB/BSC-Dust model. IZO-Eq presents better performance than the other equations in both dry and wet seasons when compared with observed PM10 at two Sahelian sites. IZO-Eq is also able to reproduce the surface concentration variability simulated by NMMB/BSC-Dust. Above 10 km of horizontal visibility, empirical equations cannot be used to estimate PM10, since above this threshold equations estimate a nearly constant PM10 value, regardless of the visibility range. A comparison between the PM10 spatial distributions derived from visibility SYNOP observations through IZO-Eq, the modelled values from the NMMB/BSC-Dust model and aerosol optical depth (AOD) retrieved from MODIS is performed for the 2006-2008 period. The different spatial distributions present a rather good agreement among them as well as to reproduce the characteristic seasonal dust features over North Africa. ; The present work was carried out in the framework of the Monitoring Atmospheric Composition and Climate (MACC-II) project under the European Union Seventh Research Framework Program (Grant Agreement Number 283576), and as part of the activities of the World Meteorological Organization Sand and ...

A demonstration study to examine the feasibility of retrieving dust radiative effects based on combined satellite data from MODIS (Moderate Resolution Imaging Spectroradiometer), CERES (Clouds and the Earth's Radiant Energy System) and CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization) lidar vertical profiles along their orbit is presented. The GAME (Global Atmospheric Model) radiative transfer model is used to estimate the shortwave and longwave dust radiative effects below the CALIPSO (Cloud- Aerosol Lidar and Infrared Pathfinder Satellite) orbit assuming an aerosol parameterization based on the CALIOP vertical distribution at a horizontal resolution of 5 km and additional AERONET (Aerosol Robotic Network) data. Two study cases are analyzed: a strong long-range transport mineral dust event (aerosol optical depth, AOD, of 0.52) that originated in the Sahara Desert and reached the United Kingdom and a weaker event (AOD D0.16) that affected eastern Europe. The radiative fluxes obtained are first validated in terms of radiative efficiency at a single point with space– time colocated lidar ground-based measurements from EARLINET (European Aerosol Research Lidar Network) stations below the orbit. The methodology is then applied to the full orbit. The strong dependence of the radiative effects on the aerosol load (and to a lesser extent on the surface albedo) highlights the need for accurate AOD measurements for radiative studies. The calculated dust radiative effects and heating rates below the orbits are in good agreement with previous studies of mineral dust, with the radiative efficiency obtained at the surface ranging between -80:3 and -63:0Wm-2 for lower dust concentration event and -119:1 and -79:3Wm-2 for the strong event. Thus, results demonstrate the validity of the method presented here to retrieve 2-D accurate radiative properties with large spatial and temporal coverage. ; This work was supported by the Juan de la Cierva-Formación program (grant no. FJCI-2015-23904); the European Union through the H2020 program (ACTRIS-2, grant no. 654109; ECARS, grant no. 602014; EUNADICS-AV, grant no. 723986); the Spanish Ministry of Economy and Competitiveness CE17 55 (project TEC2015-63832-P); the EFRD (European Fund for Regional Development); the Spanish Ministry of Science, Innovation and Universities (project CGL2017-90884-REDT); and the Unidad de Excelencia Maria de Maeztu (project MDM-2016- 0600) financed by the Spanish Agencia Estatal de Investigación.

Abstract
A growing focus on sustainability increases the need for renovation and repurposing of existing building stock to increase energy efficiency without material waste. Indoor demolition and renovation, rather than total demolition and rebuilding, produces an altered exposure situation for the workers involved. The outer shell of the building is often kept intact and protected, while the inner structure is being demolished and rebuilt, leading to an enclosed working environment.
In this study personal respirable dust and respirable crystalline silica (RCS) samples were collected at 14 demolition sites. The samples were analyzed with X-ray diffraction using the NIOSH 7500 method for RCS. During the measurements workers did manual demolition and cleaning out silica containing materials. The exposure measurements showed that 18 % of the respirable samples and 57 % of the RCS samples were above the Norwegian occupational exposure limits (OELs) of 5 and 0.05 mg/m3, respectively.
In addition, an assessment was performed on indirectly exposed workers, working within the same buildings. These workers showed a substantial exposure to RCS with 15 % of samples being above the Norwegian OEL, despite not working with silica containing materials. Indirectly exposed workers are often overlooked in exposure assessments or regarded as unexposed since they are not producing or resuspending the pollutant. Furthermore, the workers themselves are less aware of the exposure and thereby less likely to use dust protection.

We present the dust module in the Multiscale Online Non-hydrostatic AtmospheRe CHemistry model (MONARCH) version 2.0, a chemical weather prediction system that can be used for regional and global modeling at a range of resolutions. The representations of dust processes in MONARCH were upgraded with a focus on dust emission (emission parameterizations, entrainment thresholds, considerations of soil moisture and surface cover), lower boundary conditions (roughness, potential dust sources), and dust–radiation interactions. MONARCH now allows modeling of global and regional mineral dust cycles using fundamentally different paradigms, ranging from strongly simplified to physics-based parameterizations. We present a detailed description of these updates along with four global benchmark simulations, which use conceptually different dust emission parameterizations, and we evaluate the simulations against observations of dust optical depth. We determine key dust parameters, such as global annual emission/deposition flux, dust loading, dust optical depth, mass-extinction efficiency, single-scattering albedo, and direct radiative effects. For dust-particle diameters up to 20¿µm, the total annual dust emission and deposition fluxes obtained with our four experiments range between about 3500 and 6000¿Tg, which largely depend upon differences in the emitted size distribution. Considering ellipsoidal particle shapes and dust refractive indices that account for size-resolved mineralogy, we estimate the global total (longwave and shortwave) dust direct radiative effect (DRE) at the surface to range between about -0.90 and -0.63¿W¿m-2 and at the top of the atmosphere between -0.20 and -0.28¿W¿m-2. Our evaluation demonstrates that MONARCH is able to reproduce key features of the spatiotemporal variability of the global dust cycle with important and insightful differences between the different configurations. ; This research has been supported by the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement no. 789630. Martina Klose has received funding through the Helmholtz Association's Initiative and Networking Fund (grant agreement no. VH-NG-1533). Jeronimo Escribano and Matthew L. Dawson have received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreements no. 754433 (Jeronimo Escribano) and no. 747048 (Matthew Dawson). BSC co-authors acknowledge funding from the following: the European Research Council (FRAGMENT (grant no. 773051)); the AXA Research Fund; the Spanish Ministry of Science, Innovation and Universities (grant no. CGL2017- 88911-R); the EU H2020 project FORCES (grant no. 821205); the CMUG-CCI3-TECHPROP contract, an activity carried out under a program of and funded by the European Space Agency (ESA); and the DustClim project, which is part of ERA4CS, an ERA-NET initiated by JPI Climate and funded by FORMAS (SE), DLR (DE), BMWFW (AT), IFD (DK), MINECO (ES), and ANR (FR), with cofunding by the European Union (grant no. 690462). Ron L. Miller is funded by the NASA Modeling, Analysis and Prediction Program (NNG14HH42I). Jasper F. Kok acknowledges support from the National Science Foundation (NSF) under grant nos. 1552519 and 1856389 and the Army Research Office (grant no. W911NF-20- 2-0150). Yue Huang has received funding from the Columbia University Earth Institute Postdoctoral Research Fellowship and from NASA (grant no. 80NSSC19K1346) awarded under the Future Investigators in NASA Earth and Space Science and Technology (FINESST) program. ; Peer Reviewed ; Postprint (published version)