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Reynolds C, Ross C, Cullinan P, Blanc P. Silicosis initially presenting with empyema. Occup Med (Lond) 2024:kqae047. [PMID: 38856490 DOI: 10.1093/occmed/kqae047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2024] Open
Abstract
The current global outbreak of artificial stone silicosis is a recrudescence of a major occupational disease in the context of a novel exposure source. Respirable crystalline silica exposure, even without frank pneumoconiosis, is associated with an increased risk of respiratory infection. Empyema is a well-recognized complication of bacterial pneumonia; pneumonia among working-age adults, in turn, has been epidemiologically linked to occupational exposure to fumes and dust, including silica. A connection between empyema and silica dust inhalation has not been reported, however, whether through antecedent pneumonia or another mechanism. We describe a case of silicosis initially presenting with empyema in a 31-year-old Computerized Numerical Control stone-cutting machine operator who had heavy exposure to artificial stone and other rock dust.
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Affiliation(s)
- C Reynolds
- National Heart and Lung Institute, Imperial College London, London, UK
- Imperial College Healthcare NHS Trust, London, UK
| | - C Ross
- Imperial College Healthcare NHS Trust, London, UK
| | - P Cullinan
- National Heart and Lung Institute, Imperial College London, London, UK
| | - P Blanc
- University of California San Francisco School of Medicine, San Francisco, California, USA
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2
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Song Y, Yen S, Southam K, Gaskin S, Hoy RF, Zosky GR. The aryl hydrocarbon receptor pathway is a marker of lung cell activation but does not play a central pathologic role in engineered stone-associated silicosis. J Appl Toxicol 2024. [PMID: 38837244 DOI: 10.1002/jat.4653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 04/29/2024] [Accepted: 05/20/2024] [Indexed: 06/07/2024]
Abstract
Engineered stone-associated silicosis is characterised by a rapid progression of fibrosis linked to a shorter duration of exposure. To date, there is lack of information about molecular pathways that regulates disease development and the aggressiveness of this form of silicosis. Therefore, we compared transcriptome responses to different engineered stone samples and standard silica. We then identified and further tested a stone dust specific pathway (aryl hydrocarbon receptor [AhR]) in relation to mitigation of adverse lung cell responses. Cells (epithelial cells, A549; macrophages, THP-1) were exposed to two different benchtop stone samples, standard silica and vehicle control, followed by RNA sequencing analysis. Bioinformatics analyses were conducted, and the expression of dysregulated AhR pathway genes resulting from engineered stone exposure was then correlated with cytokine responses. Finally, we inhibited AhR pathway in cells pretreated with AhR antagonist and observed how this impacted cell cytotoxicity and inflammation. Through transcriptome analysis, we identified the AhR pathway genes (CYP1A1, CYP1B1 and TIPARP) that showed differential expression that was unique to engineered stones and common between both cell types. The expression of these genes was positively correlated with interleukin-8 production in A549 and THP-1 cells. However, we only observed a mild effect of AhR pathway inhibition on engineered stone dust induced cytokine responses. Given the dual roles of AhR pathway in physiological and pathological processes, our data showed that expression of AhR target genes could be markers for assessing toxicity of engineered stones; however, AhR pathway might not play a significant pathologic role in engineered stone-associated silicosis.
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Affiliation(s)
- Yong Song
- Menzies Institute for Medical Research, College of Health and Medicine, University of Tasmania, Hobart, Tasmania, Australia
| | - Seiha Yen
- Menzies Institute for Medical Research, College of Health and Medicine, University of Tasmania, Hobart, Tasmania, Australia
| | - Katherine Southam
- Menzies Institute for Medical Research, College of Health and Medicine, University of Tasmania, Hobart, Tasmania, Australia
| | - Sharyn Gaskin
- Adelaide Exposure Science and Health, School of Public Health, University of Adelaide, Adelaide, South Australia, Australia
| | - Ryan F Hoy
- Monash Centre for Occupational and Environmental Health, School of Public Health & Preventive Medicine, Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, Victoria, Australia
- Department of Respiratory Medicine, Alfred Health, Melbourne, Victoria, Australia
| | - Graeme R Zosky
- Menzies Institute for Medical Research, College of Health and Medicine, University of Tasmania, Hobart, Tasmania, Australia
- Tasmanian School of Medicine, College of Health and Medicine, University of Tasmania, Hobart, Tasmania, Australia
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Ramkissoon C, Gaskin S, Song Y, Pisaniello D, Zosky GR. From Engineered Stone Slab to Silicosis: A Synthesis of Exposure Science and Medical Evidence. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2024; 21:683. [PMID: 38928930 PMCID: PMC11203299 DOI: 10.3390/ijerph21060683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Revised: 05/23/2024] [Accepted: 05/23/2024] [Indexed: 06/28/2024]
Abstract
Engineered stone (ES) is a popular building product, due to its architectural versatility and generally lower cost. However, the fabrication of organic resin-based ES kitchen benchtops from slabs has been associated with alarming rates of silicosis among workers. In 2024, fifteen years after the first reported ES-related cases in the world, Australia became the first country to ban the use and importation of ES. A range of interacting factors are relevant for ES-associated silicosis, including ES material composition, characteristics of dust exposure and lung cell-particle response. In turn, these are influenced by consumer demand, work practices, particle size and chemistry, dust control measures, industry regulation and worker-related characteristics. This literature review provides an evidence synthesis using a narrative approach, with the themes of product, exposure and host. Exposure pathways and pathogenesis are explored. Apart from crystalline silica content, consideration is given to non-siliceous ES components such as resins and metals that may modify chemical interactions and disease risk. Preventive effort can be aligned with each theme and associated evidence.
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Affiliation(s)
- Chandnee Ramkissoon
- Adelaide Exposure Science and Health, School of Public Health, University of Adelaide, Adelaide, SA 5064, Australia; (S.G.); (D.P.)
| | - Sharyn Gaskin
- Adelaide Exposure Science and Health, School of Public Health, University of Adelaide, Adelaide, SA 5064, Australia; (S.G.); (D.P.)
| | - Yong Song
- Menzies Institute for Medical Research, College of Health and Medicine, University of Tasmania, Hobart, TAS 7000, Australia; (Y.S.); (G.R.Z.)
| | - Dino Pisaniello
- Adelaide Exposure Science and Health, School of Public Health, University of Adelaide, Adelaide, SA 5064, Australia; (S.G.); (D.P.)
| | - Graeme R. Zosky
- Menzies Institute for Medical Research, College of Health and Medicine, University of Tasmania, Hobart, TAS 7000, Australia; (Y.S.); (G.R.Z.)
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Ramkissoon C, Song Y, Yen S, Southam K, Page S, Pisaniello D, Gaskin S, Zosky GR. Understanding the pathogenesis of engineered stone-associated silicosis: The effect of particle chemistry on the lung cell response. Respirology 2024; 29:217-227. [PMID: 38043119 DOI: 10.1111/resp.14625] [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: 06/20/2023] [Accepted: 11/12/2023] [Indexed: 12/05/2023]
Abstract
BACKGROUND AND OBJECTIVE The resurgence of severe and progressive silicosis among engineered stone benchtop industry workers is a global health crisis. We investigated the link between the physico-chemical characteristics of engineered stone dust and lung cell responses to understand components that pose the greatest risk. METHODS Respirable dust from 50 resin-based engineered stones, 3 natural stones and 2 non-resin-based materials was generated and analysed for mineralogy, morphology, metals, resin, particle size and charge. Human alveolar epithelial cells and macrophages were exposed in vitro to dust and assessed for cytotoxicity and inflammation. Principal component analysis and stepwise linear regression were used to explore the relationship between engineered stone components and the cellular response. RESULTS Cutting engineered stone generated fine particles of <600 nm. Crystalline silica was the main component with metal elements such as Ti, Cu, Co and Fe also present. There was some evidence to suggest differences in cytotoxicity (p = 0.061) and IL-6 (p = 0.084) between dust samples. However, IL-8 (CXCL8) and TNF-α levels in macrophages were clearly variable (p < 0.05). Quartz explained 11% of the variance (p = 0.019) in macrophage inflammation while Co and Al accounted for 32% of the variance (p < 0.001) in macrophage toxicity, suggesting that crystalline silica only partly explains the cell response. Two of the reduced-silica, non-engineered stone products induced considerable inflammation in macrophages. CONCLUSION These data suggest that silica is not the only component of concern in these products, highlighting the caution required as alternative materials are produced in an effort to reduce disease risk.
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Affiliation(s)
- Chandnee Ramkissoon
- Adelaide Exposure Science and Health, School of Public Health, University of Adelaide, Adelaide, South Australia, Australia
| | - Yong Song
- Menzies Institute for Medical Research, College of Health and Medicine, University of Tasmania, Hobart, Australia
| | - Seiha Yen
- Menzies Institute for Medical Research, College of Health and Medicine, University of Tasmania, Hobart, Australia
| | - Katherine Southam
- Menzies Institute for Medical Research, College of Health and Medicine, University of Tasmania, Hobart, Australia
| | - Simone Page
- Menzies Institute for Medical Research, College of Health and Medicine, University of Tasmania, Hobart, Australia
| | - Dino Pisaniello
- Adelaide Exposure Science and Health, School of Public Health, University of Adelaide, Adelaide, South Australia, Australia
| | - Sharyn Gaskin
- Adelaide Exposure Science and Health, School of Public Health, University of Adelaide, Adelaide, South Australia, Australia
| | - Graeme R Zosky
- Menzies Institute for Medical Research, College of Health and Medicine, University of Tasmania, Hobart, Australia
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Lu Y, Mu M, RenChen X, Wang W, Zhu Y, Zhong M, Jiang Y, Tao X. 2-Deoxy-D-glucose ameliorates inflammation and fibrosis in a silicosis mouse model by inhibiting hypoxia-inducible factor-1α in alveolar macrophages. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2024; 269:115767. [PMID: 38039851 DOI: 10.1016/j.ecoenv.2023.115767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2023] [Revised: 11/12/2023] [Accepted: 11/27/2023] [Indexed: 12/03/2023]
Abstract
Inhaling silica causes the occupational illness silicosis, which mostly results in the gradual fibrosis of lung tissue. Previous research has demonstrated that hypoxia-inducible factor-1α (HIF-1α) and glycolysis-related genes are up-regulated in silicosis. The role of 2-deoxy-D-glucose (2-DG) as an inhibitor of glycolysis in silicosis mouse models and its molecular mechanisms remain unclear. Therefore, we used 2-DG to observe its effect on pulmonary inflammation and fibrosis in a silicosis mouse model. Furthermore, in vitro cell experiments were conducted to explore the specific mechanisms of HIF-1α. Our study found that 2-DG down-regulated HIF-1α levels in alveolar macrophages induced by silica exposure and reduced the interleukin-1β (IL-1β) level in pulmonary inflammation. Additionally, 2-DG reduced silica-induced pulmonary fibrosis. From these findings, we hypothesize that 2-DG reduced glucose transporter 1 (GLUT1) expression by inhibiting glycolysis, which inhibits the expression of HIF-1α and ultimately reduces transcription of the inflammatory cytokine, IL-1β, thus alleviating lung damage. Therefore, we elucidated the important regulatory role of HIF-1α in an experimental silicosis model and the potential defense mechanisms of 2-DG. These results provide a possible effective strategy for 2-DG in the treatment of silicosis.
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Affiliation(s)
- Yuting Lu
- School of Public Health, Anhui University of Science and Technology, China; Key Laboratory of Industrial Dust Prevention and Control, Occupational Safety and Health, Ministry of Education, Anhui University of Science and Technology, China
| | - Min Mu
- School of Public Health, Anhui University of Science and Technology, China; Key Laboratory of Industrial Dust Prevention and Control, Occupational Safety and Health, Ministry of Education, Anhui University of Science and Technology, China; Anhui Institute of Occupational Safety and Health, Anhui University of Science and Technology, China; Joint Research Center of Occupational Medicine and Health, Institute of Grand Health, Hefei Comprehensive National Science Center, Anhui University of Science and Technology, China.
| | - Xiaotian RenChen
- School of Public Health, Anhui University of Science and Technology, China; Key Laboratory of Industrial Dust Prevention and Control, Occupational Safety and Health, Ministry of Education, Anhui University of Science and Technology, China
| | - Wenyang Wang
- School of Public Health, Anhui University of Science and Technology, China; Key Laboratory of Industrial Dust Prevention and Control, Occupational Safety and Health, Ministry of Education, Anhui University of Science and Technology, China; Anhui Institute of Occupational Safety and Health, Anhui University of Science and Technology, China
| | - Yingrui Zhu
- School of Public Health, Anhui University of Science and Technology, China; Key Laboratory of Industrial Dust Prevention and Control, Occupational Safety and Health, Ministry of Education, Anhui University of Science and Technology, China
| | - Meiping Zhong
- School of Public Health, Anhui University of Science and Technology, China; Key Laboratory of Industrial Dust Prevention and Control, Occupational Safety and Health, Ministry of Education, Anhui University of Science and Technology, China
| | - Yuerong Jiang
- School of Public Health, Anhui University of Science and Technology, China; Key Laboratory of Industrial Dust Prevention and Control, Occupational Safety and Health, Ministry of Education, Anhui University of Science and Technology, China
| | - Xinrong Tao
- School of Public Health, Anhui University of Science and Technology, China; Key Laboratory of Industrial Dust Prevention and Control, Occupational Safety and Health, Ministry of Education, Anhui University of Science and Technology, China; Anhui Institute of Occupational Safety and Health, Anhui University of Science and Technology, China; Joint Research Center of Occupational Medicine and Health, Institute of Grand Health, Hefei Comprehensive National Science Center, Anhui University of Science and Technology, China
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León-Jiménez A. New Etiological Agents of Silicosis. Arch Bronconeumol 2023:S0300-2896(23)00099-6. [PMID: 36967343 DOI: 10.1016/j.arbres.2023.03.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2022] [Revised: 02/28/2023] [Accepted: 03/01/2023] [Indexed: 06/18/2023]
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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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Ramkissoon C, Gaskin S, Hall T, Pisaniello D, Zosky G. Engineered Stone Fabrication Work Releases Volatile Organic Compounds Classified as Lung Irritants. Ann Work Expo Health 2022; 67:288-293. [PMID: 36239208 PMCID: PMC9923029 DOI: 10.1093/annweh/wxac068] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 08/11/2022] [Accepted: 09/08/2022] [Indexed: 11/13/2022] Open
Abstract
Engineered stones are often characterized for their crystalline silica content. Their organic composition, particularly that of the emissions generated during fabrication work using hand-held power tools, is relatively unexplored. We forensically screened the emissions from dry-cutting 12 engineered stone products in a test chamber for their organic composition by pyrolysis-gas chromatography-mass spectrometry (GC-MS) plus selected traditional capture and analysis techniques. Phthalic anhydride, which has a Respiratory Sensitization (RSEN) Notation by the American Conference of Governmental Industrial Hygienists (ACGIH), was the most common and abundant compound, at 26-85% of the total organic composition of engineered stone emissions. Benzaldehyde and styrene were also present in all twelve samples. During active cutting, the predominant volatile organic compound (VOC) emitted was styrene, with phthalic anhydride, benzene, ethylbenzene, and toluene also detected. These results have important health implications as styrene and phthalic anhydride are irritants to the respiratory tract. This study suggests a risk of concurrent exposure to high levels of respirable crystalline silica and organic lung irritants during engineered stone fabrication work.
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Affiliation(s)
- Chandnee Ramkissoon
- Author to whom correspondence should be addressed. Tel: +610883134957; e-mail:
| | - Sharyn Gaskin
- Adelaide Exposure Science and Health, School of Public Health, University of Adelaide, Adelaide, SA 5031, Australia
| | - Tony Hall
- Mawson Analytical Spectrometry Services, School of Physical Sciences, University of Adelaide, Adelaide, SA 5000, Australia
| | - Dino Pisaniello
- Adelaide Exposure Science and Health, School of Public Health, University of Adelaide, Adelaide, SA 5031, Australia
| | - Graeme Zosky
- Menzies Institute for Medical Research, College of Health and Medicine, University of Tasmania, Hobart, TAS 7000, Australia
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Tang Q, Xing C, Li M, Jia Q, Bo C, Zhang Z. Pirfenidone ameliorates pulmonary inflammation and fibrosis in a rat silicosis model by inhibiting macrophage polarization and JAK2/STAT3 signaling pathways. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2022; 244:114066. [PMID: 36108436 DOI: 10.1016/j.ecoenv.2022.114066] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 09/03/2022] [Accepted: 09/06/2022] [Indexed: 06/15/2023]
Abstract
Macrophages play an important role in causing silicosis eventually becoming an irreversible fibrotic disease, and there are no specific drugs for silicosis in the clinic so far. Pirfenidone has consistently been shown to have anti-inflammatory and anti-fibrotic effects, but the specific mechanism by which it ameliorates fibrosis in silicosis is unclear. A rat silicosis model was established in this study, and lung tissues and serum were collected by batch execution at 14, 28, and 56 days. Also, the effects of Pirfenidone on macrophage polarization and pulmonary fibrosis were evaluated in silicosis with early intervention and late treatment by histological examination, Enzyme-linked immunosorbent assay, Hydroxyproline assay, Western blot and Quantitative reverse transcription polymerase chain reaction. The results showed that Pirfenidone significantly reduced pulmonary fibrosis in rats with silicosis, and both early intervention and late treatment effectively inhibited the expression of α-SMA, Col-I, Vimentin, Hydroxyproline, IL-1β, IL-18, and the M2 macrophage marker CD206 and Arg-1, while only early intervention effectively inhibited E-cad, TGF-β1, TNF-α, and the M1 macrophage marker iNOS, CD86. Furthermore, Pirfenidone dramatically reduced the mRNA expression of the JAK2/STAT3. These findings imply that Pirfenidone may reduce pulmonary fibrosis in silicosis rats by inhibiting macrophage polarization via the JAK2/STAT3 signaling pathway.
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Affiliation(s)
- Qiong Tang
- Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong 250000, China; Shandong Academy of Occupational Health and Occupational Medicine, Jinan, Shandong 250000, China
| | - Chen Xing
- Jinan Center For Disease Control And Prevention, Jinan, Shandong 250000, China
| | - Ming Li
- Shandong Academy of Occupational Health and Occupational Medicine, Jinan, Shandong 250000, China
| | - Qiang Jia
- Shandong Academy of Occupational Health and Occupational Medicine, Jinan, Shandong 250000, China
| | - Cunxiang Bo
- Shandong Academy of Occupational Health and Occupational Medicine, Jinan, Shandong 250000, China.
| | - Zhenling Zhang
- Shandong Academy of Occupational Health and Occupational Medicine, Jinan, Shandong 250000, China.
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Characterization of Si and SiO 2 in Dust Emitted during Granite Polishing as a Function of Cutting Conditions. MATERIALS 2022; 15:ma15113965. [PMID: 35683263 PMCID: PMC9182374 DOI: 10.3390/ma15113965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 05/18/2022] [Accepted: 05/24/2022] [Indexed: 11/17/2022]
Abstract
Particles emitted during manufacturing processes such as polishing can represent a serious danger for the environment and for occupational safety. The formation mechanisms responsible for these dust emissions include chip formation, friction at the tool/workpiece and chip/tool interfaces, shearing and cutting. These mechanisms thus depend on workpiece and tool properties, as well as the polishing conditions. In the case of granite polishing, particle emissions during polishing can contain chemical compounds such as silica, which represent harmful health risks for the worker. It is therefore important to characterize the particles emitted and to search for possible interactions between the particles (size and composition) and the machining conditions in order to find ways of reducing emissions at the source. In this study, an investigation was undertaken to characterize the particles emitted during granite polishing as a function of polishing conditions, type of granite, and abrasive grit sizes used. Scanning electron microscopy (SEM) was employed for particle morphology characterization and particle grain size and chemical composition were evaluated using X-ray diffraction (XRD) and energy dispersive X-ray (EDX) techniques, respectively. Results show that the influence of polishing speed and feed rate on particle emission depends mainly on the granite type used, providing useful information for controlling the polishing procedure, and thereby dust emission.
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11
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Thredgold L, Ramkissoon C, Kumarasamy C, Gun R, Rowett S, Gaskin S. Rapid Assessment of Oxidative Damage Potential: A Comparative Study of Engineered Stone Dusts Using a Deoxyguanosine Assay. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19106221. [PMID: 35627757 PMCID: PMC9140999 DOI: 10.3390/ijerph19106221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 05/09/2022] [Accepted: 05/16/2022] [Indexed: 11/21/2022]
Abstract
The popularity of engineered stone (ES) has been associated with a global increase in occupational lung disease in workers exposed to respirable dust during the fabrication of benchtops and other ES products. In this study, the reactivity and subsequent oxidative reduction potential of freshly generated ES dusts were evaluated by (i) comparing different engineered and natural stones, (ii) comparing settled and respirable stone dust fractions and (iii) assessing the effect of ageing on the reactivity of freshly generated stone dust. An established cell-free deoxyguanosine hydroxylation assay was used to assess the potential for oxidative DNA damage. ES dust exhibited a higher relative reactivity than two of the three natural stones tested. Respirable dust fractions were found to be significantly more reactive than their corresponding settled fraction (ANOVA, p < 0.05) across all stone types and samples. However, settled dust still displayed high relative reactivity. The lower reactivity of the settled dust was not due to decay in reactivity of the respirable dust when it settled but rather a result of the admixture of larger nonrespirable particles. No significant change in respirable dust reactivity was observed for three ES samples over a 21-day time period, whereas a significant decrease in reactivity was observed in the natural stone studied. This study has practical implications for dust control and housekeeping in industry, risk assessment and hazard management.
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Affiliation(s)
- Leigh Thredgold
- Adelaide Exposure Science and Health, School of Public Health, University of Adelaide, Adelaide, SA 5005, Australia; (L.T.); (C.R.); (C.K.); (R.G.)
| | - Chandnee Ramkissoon
- Adelaide Exposure Science and Health, School of Public Health, University of Adelaide, Adelaide, SA 5005, Australia; (L.T.); (C.R.); (C.K.); (R.G.)
| | - Chellan Kumarasamy
- Adelaide Exposure Science and Health, School of Public Health, University of Adelaide, Adelaide, SA 5005, Australia; (L.T.); (C.R.); (C.K.); (R.G.)
| | - Richard Gun
- Adelaide Exposure Science and Health, School of Public Health, University of Adelaide, Adelaide, SA 5005, Australia; (L.T.); (C.R.); (C.K.); (R.G.)
| | - Shelley Rowett
- SafeWork SA, Government of South Australia, Adelaide, SA 5035, Australia;
| | - Sharyn Gaskin
- Adelaide Exposure Science and Health, School of Public Health, University of Adelaide, Adelaide, SA 5005, Australia; (L.T.); (C.R.); (C.K.); (R.G.)
- Correspondence:
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