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Ervik TK, Leite M, Weinbruch S, Nordby KC, Ellingsen DG, Ulvestad B, Dahl K, Berlinger B, Skaugset NP. Characterization of particle exposure during tunnel excavation by tunnel boring machines. Ann Work Expo Health 2024; 68:713-724. [PMID: 38816184 PMCID: PMC11306322 DOI: 10.1093/annweh/wxae041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Accepted: 05/02/2024] [Indexed: 06/01/2024] Open
Abstract
Tunnel boring machines (TBMs) are used to excavate tunnels in a manner where the rock is constantly penetrated with rotating cutter heads. Fine particles of the rock minerals are thereby generated. Workers on and in the vicinity of the TBM are exposed to particulate matter (PM) consisting of bedrock minerals including α-quartz. Exposure to respirable α-quartz remains a concern because of the respiratory diseases associated with this exposure. The particle size distribution of PM and α-quartz is of special importance because of its influence on adverse health effects, monitoring and control strategies as well as accurate quantification of α-quartz concentrations. The major aim of our study was therefore to investigate the particle size distribution of airborne PM and α-quartz generated during tunnel excavation using TBMs in an area dominated by gneiss, a metamorphic type of rock. Sioutas cascade impactors were used to collect personal samples on 3 separate days. The impactor fractionates the dust in 5 size fractions, from 10 µm down to below 0.25 µm. The filters were weighted, and the α-quartz concentrations were quantified using X-ray diffraction (XRD) analysis and the NIOSH 7500 method on the 5 size fractions. Other minerals were determined using Rietveld refinement XRD analysis. The size and elemental composition of individual particles were investigated by scanning electron microscopy. The majority of PM mass was collected on the first 3 stages (aerodynamic diameter = 10 to 0.5 µm) of the Sioutas cascade impactor. No observable differences were found for the size distribution of the collected PM and α-quartz for the 3 sampling days nor the various work tasks. However, the α-quartz proportion varied for the 3 sampling days demonstrating a dependence on geology. The collected α-quartz consisted of more particles with sizes below 1 µm than the calibration material, which most likely affected the accuracy of the measured respirable α-quartz concentrations. This potential systematic error is important to keep in mind when analyzing α-quartz from occupational samples. Knowledge of the particle size distribution is also important for control measures, which should target particle sizes that efficiently capture the respirable α-quartz concentration.
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Affiliation(s)
- Torunn K Ervik
- National Institute of Occupational Health, P.O. Box 5330, Majorstuen, 0304 Oslo, Norway
| | - Mimmi Leite
- National Institute of Occupational Health, P.O. Box 5330, Majorstuen, 0304 Oslo, Norway
| | - Stephan Weinbruch
- National Institute of Occupational Health, P.O. Box 5330, Majorstuen, 0304 Oslo, Norway
- Technical University of Darmstadt, Institute of Applied Geosciences, Schnittspahnstrasse 9, D-64287, Darmstadt, Germany
| | - Karl-Christian Nordby
- National Institute of Occupational Health, P.O. Box 5330, Majorstuen, 0304 Oslo, Norway
| | - Dag G Ellingsen
- National Institute of Occupational Health, P.O. Box 5330, Majorstuen, 0304 Oslo, Norway
| | - Bente Ulvestad
- National Institute of Occupational Health, P.O. Box 5330, Majorstuen, 0304 Oslo, Norway
| | - Kari Dahl
- National Institute of Occupational Health, P.O. Box 5330, Majorstuen, 0304 Oslo, Norway
| | - Balazs Berlinger
- National Institute of Occupational Health, P.O. Box 5330, Majorstuen, 0304 Oslo, Norway
| | - Nils Petter Skaugset
- National Institute of Occupational Health, P.O. Box 5330, Majorstuen, 0304 Oslo, Norway
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Thompson D, Qi C. Characterization of the Emissions and Crystalline Silica Content of Airborne Dust Generated from Grinding Natural and Engineered Stones. Ann Work Expo Health 2023; 67:266-280. [PMID: 36219621 PMCID: PMC9928769 DOI: 10.1093/annweh/wxac070] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 08/31/2022] [Accepted: 09/21/2022] [Indexed: 11/12/2022] Open
Abstract
In this study, we systematically characterized the airborne dust generated from grinding engineered and natural stone products using a laboratory testing system designed and operated to collect representative respirable dust samples. Four stone samples tested included two engineered stones consisting of crystalline silica in a polyester resin matrix (formulations differed with Stones A having up to 90wt% crystalline silica and Stone B up to 50wt% crystalline silica), an engineered stone consisting of recycled glass in a cement matrix (Stone C), and a granite. Aerosol samples were collected by respirable dust samplers, total dust samplers, and a Micro-Orifice Uniform Deposit Impactor. Aerosol samples were analyzed by gravimetric analysis and x-ray diffraction to determine dust generation rates, crystalline silica generation rates, and crystalline silica content. Additionally, bulk dust settled on the floor of the testing system was analyzed for crystalline silica content. Real-time particle size distributions were measured using an Aerodynamic Particle Sizer. All stone types generated similar trimodal lognormal number-weighted particle size distributions during grinding with the most prominent mode at an aerodynamic diameter of about 2.0-2.3 μm, suggesting dust formation from grinding different stones is similar. Bulk dust from Stone C contained no crystalline silica. Bulk dust from Stone A, Stone B, and granite contained 60, 23, and 30wt% crystalline silica, respectively. In Stones A and B, the cristobalite form of crystalline silica was more plentiful than the quartz form. Only the quartz form was detected in granite. The bulk dust, respirable dust, and total dust for each stone had comparable amounts of crystalline silica, suggesting that crystalline silica content in the bulk dust could be representative of that in respirable dust generated during grinding. Granite generated more dust per unit volume of material removed than the engineered stones, which all had similar normalized dust generation rates. Stone A had the highest normalized generation rates of crystalline silica, followed by granite, Stone B, and Stone C (no crystalline silica), which likely leads to the same trend of respirable crystalline silica (RCS) exposure when working with these different stones. Manufacturing and adoption of engineered stone products with formulations such as Stone B or Stone C could potentially lower or eliminate RCS exposure risks. Combining all the effects of dust generation rate, size-dependent silica content, and respirable fraction, the highest normalized generation rate of RCS consistently occurs at 3.2-5.6 µm for all the stones containing crystalline silica. Therefore, removing particles in this size range near the generation sources should be prioritized when developing engineering control measures.
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Affiliation(s)
- Drew Thompson
- Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Division of Field Studies and Engineering, Cincinnati, OH 45226, USA
| | - Chaolong Qi
- Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Division of Field Studies and Engineering, Cincinnati, OH 45226, USA
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Paluchamy B, Mishra DP. Dust pollution hazard and harmful airborne dust exposure assessment for remote LHD operator in underground lead-zinc ore mine open stope. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:89585-89596. [PMID: 35852746 DOI: 10.1007/s11356-022-22059-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 07/12/2022] [Indexed: 06/15/2023]
Abstract
Underground mines embroil several occupational hazards, including airborne dust generation from various mining operations. Line-of-sight remote Load Haul Dumper (LHD) mucking is adopted to draw the blasted muck from unsupported open stopes in underground metalliferous mines. Assessment of particulate matter (PM) concentrations and remote LHD operator's exposure is crucial for devising appropriate dust control measures. In this study, PM generated due to mucking in longhole open stope by line-of-sight remote LHD during downcast airflow was measured using real-time aerosol spectrometers. The particulate concentrations at upstream and downstream of dust source were analysed for various particle sizes as well as occupational dust types, such as alveolic and thoracic. The airborne dust concentration of ≤ 10 μm (PM10), ≤ 5 μm, and ≤ 1 μm (PM1) size at operator's location in downstream was measured 71.3%, 28.5%, and 3.0%, respectively. The alveolic and thoracic dust types, respectively, were determined 25.1% and 74.2% in downstream and 48.9% and 84.6% in upstream total airborne dust concentration (311 ± 246 μg/m3). Dilution of airborne dust generated due to muck sliding inside the stope was analysed with time. Moreover, dust concentrations under typical airflow scenarios encountered in open stope were simulated using Ventsim software to identify the potential dust exposure hazard for remote LHD operator. The simulation revealed that downcast airflow causes maximum exposure of harmful airborne dust for remote LHD operator. This study enhanced the understanding of exposure potential of airborne dust during remote LHD mucking. Moreover, it emphasised adoption of tele-remote-operated LHD and automated mucking operation in open stopes.
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Affiliation(s)
- B Paluchamy
- Department of Mining Engineering, Indian Institute of Technology (Indian School of Mines), Dhanbad, 826 004, India
| | - Devi Prasad Mishra
- Department of Mining Engineering, Indian Institute of Technology (Indian School of Mines), Dhanbad, 826 004, India.
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Tim B, Rojewska M, Prochaska K. Effect of Silica Microparticles on Interactions in Mono- and Multicomponent Membranes. Int J Mol Sci 2022; 23:ijms232112822. [PMID: 36361613 PMCID: PMC9654498 DOI: 10.3390/ijms232112822] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 10/14/2022] [Accepted: 10/20/2022] [Indexed: 12/01/2022] Open
Abstract
Advancing our understanding of the mechanism of the interaction between inhaled pollutant microparticles and cell membrane components is useful to study the impact of fine particulate matter on human health. In this paper, we focus on the effect of cholesterol (Chol) molecules on the surface properties of a model membrane in the presence of silica microparticles (MPs). Mixed monolayers containing phospholipid-dipalmitoylphosphatidylcholine (DPPC), Chol and silica particle dispersions (MPs; 0.033% w/w, 0.33% w/w and 0.83% w/w) were formed and studied using the Langmuir monolayer technique complemented by Brewster Angle Microscopy (BAM) images. It was shown that Chol caused a condensation of the DPPC monolayer, which influenced the penetration of MPs and their interactions with the model membrane. The relaxation experiments of the lipid–MP monolayer proved that the presence of Chol molecules in the monolayer led to the formation of lipid and MP complexes. Strong interactions between Chol and MPs contributed to the formation of more stable monolayers. The presented results can be useful to better comprehend the interaction between particulate materials and the lipid components of biomembranes.
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Affiliation(s)
- Beata Tim
- Faculty of Materials Engineering and Technical Physics, Poznan University of Technology, Ul. Piotrowo 3, 60-965 Poznan, Poland
| | - Monika Rojewska
- Institute of Chemical Technology and Engineering, Poznan University of Technology, Ul. Berdychowo 4, 60-965 Poznan, Poland
- Correspondence: ; Tel.: +48-61-665-3772; Fax: +48-61-665-3649
| | - Krystyna Prochaska
- Institute of Chemical Technology and Engineering, Poznan University of Technology, Ul. Berdychowo 4, 60-965 Poznan, Poland
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Noi DDT, Davies B, Gopaldasani V. End-of-Shift Monitoring of Respirable Crystalline Silica: A Critical Review of Measurement Techniques and Factors Influencing Accurate Measurements. Crit Rev Anal Chem 2022; 54:1492-1501. [PMID: 36063400 DOI: 10.1080/10408347.2022.2117979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
This article presents the findings of a systematic literature review focusing on the impact of interferences in host materials on Respirable Crystalline Silica (RCS) measurement, and the development of a validated method of calibration for RCS instrumentation for in-field use. The impact of interferences in host materials on RCS measurement has been shown to be critical information required for in-field use of portable RCS devices. Portable RCS instruments such as FTIR and XRD have been established to have good sensitivity for measurement but relatively low specificity due to interference in host materials. It has been shown that correction factors are needed to be applied to account for known interferences, especially when calibrating portable RCS instrumentation in-field. The potential to obtain reliable and repeatable results from RCS analysis instrumentation has also been demonstrated. There was significant evidence that interference materials could be present in host materials, and they influence RCS measurement. There is the potential and possibility of using portable RCS instrument for in-field measurement however the challenge is the calibration of such instrumentation in the field to account for changing host materials and thus potential interferences.
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Affiliation(s)
- David Dennis Tettey Noi
- School of Health and Society, Faculty of Arts, Social Sciences and Health, University of Wollongong, Wollongong, New South Wales, Australia
- Centre for Occupational Public Environmental Research in Safety and Health (COPERSH), Wollongong, New South Wales, Australia
| | - Brian Davies
- School of Health and Society, Faculty of Arts, Social Sciences and Health, University of Wollongong, Wollongong, New South Wales, Australia
- Centre for Occupational Public Environmental Research in Safety and Health (COPERSH), Wollongong, New South Wales, Australia
| | - Vinod Gopaldasani
- School of Health and Society, Faculty of Arts, Social Sciences and Health, University of Wollongong, Wollongong, New South Wales, Australia
- Centre for Occupational Public Environmental Research in Safety and Health (COPERSH), Wollongong, New South Wales, Australia
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6
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Rumchev K, Hoang DV, Lee A. Case Report: Exposure to Respirable Crystalline Silica and Respiratory Health Among Australian Mine Workers. Front Public Health 2022; 10:798472. [PMID: 35769775 PMCID: PMC9234445 DOI: 10.3389/fpubh.2022.798472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 05/23/2022] [Indexed: 11/13/2022] Open
Abstract
Occupational exposure to respirable crystalline silica (RCS) is common in a range of industries, including mining, and has been associated with adverse health effects such as silicosis, lung cancer, and non-malignant respiratory diseases. This study used a large population database of 6,563 mine workers from Western Australia who were examined for personal exposure to RCS between 2001 and 2012. A standardized respiratory questionnaire was also administered to collect information related to their respiratory health. Logistic regression analyses were performed to ascertain the association between RCS concentrations and the prevalence of respiratory symptoms among mine workers. The estimated exposure levels of RCS (geometric mean 0.008mg/m3, GSD 4.151) declined over the study period (p < 0.001) and were below the exposure standard of 0.05 mg/m3. Miners exposed to RCS had a significantly higher prevalence of phlegm (p = 0.017) and any respiratory symptom (p = 0.013), even at concentrations within the exposure limit. Miners are susceptible to adverse respiratory health effects at low levels of RCS exposure. More stringent prevention strategies are therefore recommended to protect mine workers from RCS exposures.
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Affiliation(s)
- Krassi Rumchev
- School of Population Health, Curtin University, Perth, WA, Australia
- *Correspondence: Krassi Rumchev
| | - Dong Van Hoang
- Department of Epidemiology and Prevention, Center for Clinical Sciences, National Center for Global Health and Medicine, Tokyo, Japan
| | - Andy Lee
- School of Population Health, Curtin University, Perth, WA, Australia
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Wieland S, Balmes A, Bender J, Kitzinger J, Meyer F, Ramsperger AF, Roeder F, Tengelmann C, Wimmer BH, Laforsch C, Kress H. From properties to toxicity: Comparing microplastics to other airborne microparticles. JOURNAL OF HAZARDOUS MATERIALS 2022; 428:128151. [PMID: 35042167 DOI: 10.1016/j.jhazmat.2021.128151] [Citation(s) in RCA: 53] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 12/22/2021] [Accepted: 12/23/2021] [Indexed: 06/14/2023]
Abstract
Microplastic (MP) debris is considered as a potentially hazardous material. It is omnipresent in our environment, and evidence that MP is also abundant in the atmosphere is increasing. Consequently, the inhalation of these particles is a significant exposure route to humans. Concerns about potential effects of airborne MP on human health are rising. However, currently, there are not enough studies on the putative toxicity of airborne MP to adequately assess its impact on human health. Therefore, we examined potential drivers of airborne MP toxicity. Physicochemical properties like size, shape, ζ-potential, adsorbed molecules and pathogens, and the MP's bio-persistence have been proposed as possible drivers of MP toxicity. Since their role in MP toxicity is largely unknown, we reviewed the literature on toxicologically well-studied non-plastic airborne microparticles (asbestos, silica, soot, wood, cotton, hay). We aimed to link the observed health effects and toxicology of these microparticles to the abovementioned properties. By comparing this information with studies on the effects of airborne MP, we analyzed possible mechanisms of airborne MP toxicity. Thus, we provide a basis for a mechanistic understanding of airborne MP toxicity. This may enable the assessment of risks associated with airborne MP pollution, facilitating effective policymaking and product design.
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Affiliation(s)
- Simon Wieland
- Biological Physics, University of Bayreuth, Bayreuth, Germany; Animal Ecology I and BayCEER, University of Bayreuth, Bayreuth, Germany
| | - Aylin Balmes
- Institute of Applied Physics, University of Tübingen, Tübingen, Germany
| | - Julian Bender
- Institute for Biochemistry and Biotechnology, Interdisciplinary Research Center HALOmem, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Jonas Kitzinger
- Department of Physics, Humboldt University of Berlin, Berlin, Germany
| | - Felix Meyer
- Institute of Clinical Microbiology and Hygiene, University Hospital Regensburg, Regensburg, Germany
| | - Anja Frm Ramsperger
- Biological Physics, University of Bayreuth, Bayreuth, Germany; Animal Ecology I and BayCEER, University of Bayreuth, Bayreuth, Germany
| | - Franz Roeder
- Institute of Optics and Quantum Electronics, Friedrich-Schiller-University Jena, Jena, Germany
| | - Caroline Tengelmann
- Medical Faculty, University of Würzburg, Würzburg, Germany; Department of Anesthesiology, Intensive Care Medicine and Pain Therapy, University Hospital of Würzburg, Würzburg, Germany
| | | | - Christian Laforsch
- Animal Ecology I and BayCEER, University of Bayreuth, Bayreuth, Germany.
| | - Holger Kress
- Biological Physics, University of Bayreuth, Bayreuth, Germany.
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Pollard KM. Perspective: The Lung, Particles, Fibers, Nanomaterials, and Autoimmunity. Front Immunol 2020; 11:587136. [PMID: 33391263 PMCID: PMC7775503 DOI: 10.3389/fimmu.2020.587136] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 11/17/2020] [Indexed: 12/11/2022] Open
Abstract
Studies have shown that a wide range of factors including drugs, chemicals, microbes, and other environmental agents can induce pre-clinical autoimmunity. However, only a few have been confidently linked to autoimmune diseases. Among these are exposures to inhaled particulates that are known to be associated with autoimmune diseases such as lupus and rheumatoid arthritis. In this article, the potential of particle, fiber, and nanomaterial exposures to induce autoimmunity is discussed. It is hypothesized that inhalation of particulate material known to be associated with human autoimmune diseases, such as cigarette smoke and crystalline silica, results in a complex interplay of a number of pathological processes, including, toxicity, oxidative stress, cell and tissue damage, chronic inflammation, post-translational modification of self-antigens, and the formation of lymphoid follicles that provide a milieu for the accumulation of autoreactive B and T cells necessary for the development and persistence of autoimmune responses, leading to disease. Although experimental studies show nanomaterials are capable of inducing several of the above features, there is no evidence that this matures to autoimmune disease. The procession of events hypothesized here provides a foundation from which to pursue experimental studies to determine the potential of other environmental exposures to induce autoimmunity and autoimmune disease.
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Affiliation(s)
- K Michael Pollard
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, United States
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9
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Vis B, Powell JJ, Hewitt RE. Imaging flow cytometry methods for quantitative analysis of label-free crystalline silica particle interactions with immune cells. AIMS BIOPHYSICS 2020; 7:144-166. [PMID: 32642556 DOI: 10.3934/biophy.2020012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Exposure to respirable fractions of crystalline silica quartz dust particles is associated with silicosis, cancer and the development of autoimmune conditions. Early cellular interactions are not well understood, partly due to a lack of suitable technological methods. Improved techniques are needed to better quantify and study high-level respirable crystalline silica exposure in human populations. Techniques that can be applied to complex biological matrices are pivotal to understanding particle-cell interactions and the impact of particles within real, biologically complex environments. In this study, we investigated whether imaging flow cytometry could be used to assess the interactions between cells and crystalline silica when present within complex biological matrices. Using the respirable-size fine quartz crystalline silica dust Min-u-sil® 5, we first validated previous reports that, whilst associating with cells, crystalline silica particles can be detected solely through their differential light scattering profile using conventional flow cytometry. This same property reliably identified crystalline silica in association with primary monocytic cells in vitro using an imaging flow cytometry assay, where darkfield intensity measurements were able to detect crystalline silica concentrations as low as 2.5 μg/mL. Finally, we ultilised fresh whole blood as an exemplary complex biological matrix to test the technique. Even after the increased sample processing required to analyse cells within whole blood, imaging flow cytometry was capable of detecting and assessing silica-association to cells. As expected, in fresh whole blood exposed to crystalline silica, neutrophils and cells of the monocyte/macrophage lineage phagocytosed the particles. In addition to the use of this technique in in vitro exposure models, this method has the potential to be applied directly to ex vivo diagnostic studies and research models, where the identification of crystalline silica association with cells in complex biological matrices such as bronchial lavage fluids, alongside additional functional and phenotypic cellular readouts, is required.
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Affiliation(s)
- Bradley Vis
- Biomineral Research Group, Department of Veterinary Medicine, University of Cambridge, Madingley Rd, Cambridge CB3 0ES, UK
| | - Jonathan J Powell
- Biomineral Research Group, Department of Veterinary Medicine, University of Cambridge, Madingley Rd, Cambridge CB3 0ES, UK
| | - Rachel E Hewitt
- Biomineral Research Group, Department of Veterinary Medicine, University of Cambridge, Madingley Rd, Cambridge CB3 0ES, UK
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Brouwer DH, Rees D. Can the South African Milestones for Reducing Exposure to Respirable Crystalline Silica and Silicosis be Achieved and Reliably Monitored? Front Public Health 2020; 8:107. [PMID: 32318535 PMCID: PMC7154115 DOI: 10.3389/fpubh.2020.00107] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 03/18/2020] [Indexed: 11/29/2022] Open
Abstract
Silicosis and other respirable crystalline silica-associated diseases, most notably tuberculosis, have long been substantial causes of morbidity and mortality in South Africa. For the mining and non-mining industries, silicosis elimination programmes have been developed with milestones regarding reduction of levels of exposure to respirable crystalline silica (RCS) and targets regarding the date of eradication. The present paper explores the feasibility of achieving these targets by investigating the evidence that levels of exposure and silicosis incidence rates have declined by an appraisal of the methods for data collection and reporting. In the mining industry the silicosis elimination programme is supported by the development and advocacy of leading practices to reduce the exposure. RCS exposure data are routinely collected according to a Code of Practice (CoP) and the results are reported to the Mine Health and Safety Inspectorate. As the CoP and the actual workplace practices have been demonstrated to have some flaws, there is some concern about the accuracy of the actual exposure data and the data interpretation. The annually reported levels of exposure suggest a decline, however, the actual levels of RCS as well as the number of exposed workers, were not reported over the last few years. With regard to the silicosis incidence rates, a steady decline of new cases is reported. However, there is a risk of under-diagnosis and- reporting especially in former miners. In the non-mining industries, a systematic baseline of RCS exposure levels and silicosis incidence is lacking. The reporting by industries on assigning of the workforce to exposure categories seems to be fragmented and incomplete. Consequently, any evidence of progress toward achieving the silicosis elimination target cannot be documented. Both the silicosis elimination target and the exposure milestone are aspirational but are unlikely to be achieved. Nevertheless, the formal mining industry may get close. Exposure control interventions, especially in the non-mining industries, should be developed and implemented and pragmatic methods need to be put in place to identify sources of new silicosis cases for targeted intervention.
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Affiliation(s)
- Derk H Brouwer
- Faculty of Health Sciences, School of Public Health, University of the Witwatersrand, Johannesburg, South Africa
| | - David Rees
- Faculty of Health Sciences, School of Public Health, University of the Witwatersrand, Johannesburg, South Africa.,National Institute for Occupation Health, National Health Laboratory Service, Johannesburg, South Africa
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11
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Wu Q, Han L, Xu M, Zhang H, Ding B, Zhu B. Effects of occupational exposure to dust on chest radiograph, pulmonary function, blood pressure and electrocardiogram among coal miners in an eastern province, China. BMC Public Health 2019; 19:1229. [PMID: 31488099 PMCID: PMC6728990 DOI: 10.1186/s12889-019-7568-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 08/29/2019] [Indexed: 02/07/2023] Open
Abstract
Background Coal dust is one of the most serious risk factor that leads to respiratory diseases and cardiovascular diseases in miners. This study aimed to observe the effects of occupational dust exposure on chest radiograph, pulmonary function (PF), blood pressure (BP) and electrocardiogram (ECG) indexes in coal miners and explore the related risk factors. Methods In the Chinese Occupational Disease Monitoring and Occupational Health Risk Assessment Program, a total of 11,061 subjects in 2015 and 12,597 subjects in 2016 were recruited in this study. The chest radiograph, PF, BP and ECG of coal miners were surveyed using radiograph machine, spirometer, sphygmomanometer and electrocardiograph, respectively. Results The prevalence of aberrant BP was the highest in coal miners, followed by abnormal ECG, PF and radiograph. Significant differences in abnormal BP, ECG, PF and radiograph of coal miners were closely associated with age, years of dust exposure, smoking, drinking, working types and size of mines. A total of 80 persons diagnosed with coal workers’ pneumoconiosis (CWP) in 2015–2016, which occupied 0.34% of the coal miners. Conclusion Abnormal BP, ECG, PF and radiograph of coal miners are highlighted health problems in China and require serious attention. Feasible health promotion and protective facilities should be adopted to guarantee coal miners’ health. Electronic supplementary material The online version of this article (10.1186/s12889-019-7568-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Qiuyun Wu
- School of Public Health, Xuzhou Medical University, Xuzhou, 221004, China
| | - Lei Han
- Institute of Occupational Disease Prevention, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, 210009, China
| | - Ming Xu
- Institute of Occupational Disease Prevention, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, 210009, China
| | - Hengdong Zhang
- Institute of Occupational Disease Prevention, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, 210009, China
| | - Bangmei Ding
- Institute of Occupational Disease Prevention, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, 210009, China
| | - Baoli Zhu
- Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, 211166, China.
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Cauda E, Chubb L, Reed R, Stepp R. Evaluating the use of a field-based silica monitoring approach with dust from copper mines. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2018; 15:732-742. [PMID: 29985785 PMCID: PMC6319252 DOI: 10.1080/15459624.2018.1495333] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Monitoring worker exposure to respirable crystalline silica in dusty environments is an important part of a proactive health and safety program. This is the case for surface copper mines in Arizona and New Mexico. The spatial and temporal variability of respirable dust and crystalline silica concentrations in those mines, coupled with the time lapse in obtaining crystalline silica analysis results from accredited laboratories, present a challenge for an effective exposure monitoring approach and the resulting intervention strategies. The National Institute for Occupational Safety and Health (NIOSH) is developing a novel approach to be used at a mine site for the quantification of crystalline silica in respirable dust samples collected with traditional sampling techniques. The non-destructive analysis is carried out using a portable Fourier transform infrared spectroscopy (FTIR) unit. In this study, respirable dust samples were collected over two visits to each of five copper mines, for a total of 10 datasets. The silica in each respirable dust sample was estimated by analyzing the sample with the portable FTIR unit. The quality of the estimation was assessed using the results of the NIOSH 7500 method on the same samples. The confounding effect of other minerals present in the respirable dust in the mines was also assessed, and two quantification approaches were investigated to address it: a sector-specific and a mine-specific approach. The results showed that the sector-specific approach is not effective due to the high variability of relative composition of the minerals among mines. For this approach the combined average relative difference was -13% (-17.6%, -8.9% CI). When using the mine-specific quantification approach, the average relative difference was as low as 2.8% (-3.7%, 9.3% CI); however, this approach was still affected by the variable relative composition of the minerals in the dust in each mine. The use of a multivariate approach on the analysis of each sample was proposed as the next step to achieve consistent low relative differences. This study demonstrates the potential of using a portable FTIR for estimation of crystalline silica in respirable dust samples for in-field exposure monitoring.
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Affiliation(s)
- Emanuele Cauda
- Pittsburgh Mining Research Division, Dust Control, Ventilation and Toxic Substances Branch, National Institute for Occupational Safety and Health, Pittsburgh, Pennsylvania
| | - Lauren Chubb
- Pittsburgh Mining Research Division, Dust Control, Ventilation and Toxic Substances Branch, National Institute for Occupational Safety and Health, Pittsburgh, Pennsylvania
| | - Rustin Reed
- Embry-Riddle Aeronautical University, Prescot, Arizona
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Nardi J, Nascimento S, Göethel G, Gauer B, Sauer E, Fão N, Cestonaro L, Peruzzi C, Souza J, Garcia SC. Inflammatory and oxidative stress parameters as potential early biomarkers for silicosis. Clin Chim Acta 2018; 484:305-313. [PMID: 29860036 DOI: 10.1016/j.cca.2018.05.045] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 05/22/2018] [Accepted: 05/23/2018] [Indexed: 01/25/2023]
Abstract
Workers involved in mining activities are exposed to crystalline silica, which leads to constant pulmonary inflammatory reactions and severe oxidative damage, resulting in silicosis. In this work, we aimed to evaluate inflammatory and oxidative stress parameters as potential early biomarkers of effect to assess crystalline silica toxicity in workers who had occupational exposure during mining. We enrolled 38 workers exposed to crystalline silica (WECS), 24 individuals with silicosis (IWS), and 30 occupationally unexposed workers (OUW), a total of 92 participants. The WECS were divided into 2 groups, according to the time of exposure: 19 workers with 1-15 years of occupational exposure (WECS I) and 19 workers with >16 years of occupational exposure (WECS II). The inflammatory parameters assessed were L-selectin, β-2 integrin, and intercellular adhesion molecule-1 (ICAM-1) surface protein expression in lymphocytes and monocytes, complement C3 and C4, high sensitivity C-reactive protein (hsCRP), and adenosine deaminase (ADA) in serum. Plasma levels of malondialdehyde (MDA) and serum levels of vitamin C were determined as biomarkers of oxidative stress. Biochemical and hematological parameters were also investigated. L-selectin surface protein expression was significantly decreased in the WECS II group (p < 0.05), indicating the importance of this immune system component as a potential marker of crystalline-silica-induced toxicity. The MDA levels were significantly increased in the WECS I, WECS II, and IWS groups compared to the OUW group (p < 0.05). Vitamin C levels were decreased, while C3, hsCRP, ADA, and aspartate aminotransferase (AST) levels were increased in the IWS group compared to the OUW group (p < 0.05). Glucose and urea levels were significantly higher in the WECS I, II, and IWS groups compared to the OUW group (p < 0.05). Negative partial association was found between L-selectin and time of exposure (p < 0.001), supporting the relevance of this biomarker evaluation in long-term exposure to crystalline silica. Significant associations were also observed among inflammatory and oxidative stress biomarkers. Therefore, our results demonstrated the relevance of L-selectin as a potential peripheral biomarker for monitoring crystalline silica-induced toxicity in miners after chronic exposure, before silicosis has developed. However, more studies are necessary for better understanding of the use L-selectin as an early biomarker in exposed workers.
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Affiliation(s)
- Jessica Nardi
- Laboratório de Toxicologia (LATOX), Departamento de Análises, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil; Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Sabrina Nascimento
- Laboratório de Toxicologia (LATOX), Departamento de Análises, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil; Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Gabriela Göethel
- Laboratório de Toxicologia (LATOX), Departamento de Análises, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil; Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Bruna Gauer
- Laboratório de Toxicologia (LATOX), Departamento de Análises, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil; Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Elisa Sauer
- Laboratório de Toxicologia (LATOX), Departamento de Análises, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil; Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Nuryan Fão
- Laboratório de Toxicologia (LATOX), Departamento de Análises, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil; Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Larissa Cestonaro
- Laboratório de Toxicologia (LATOX), Departamento de Análises, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil; Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Caroline Peruzzi
- Laboratório de Toxicologia (LATOX), Departamento de Análises, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil; Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Jorge Souza
- Unidade Regional de Saúde do Trabalhador, Ametista do Sul, RS, Brazil
| | - Solange Cristina Garcia
- Laboratório de Toxicologia (LATOX), Departamento de Análises, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil; Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil.
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