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Khuniqi HN, Rasoulzadeh Y, Mohammadian Y. DNA damage in foundry workers using non-invasive micronucleus cytome assay. MUTATION RESEARCH. GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2023; 891:503686. [PMID: 37770143 DOI: 10.1016/j.mrgentox.2023.503686] [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: 03/12/2023] [Revised: 08/23/2023] [Accepted: 08/24/2023] [Indexed: 10/03/2023]
Abstract
Workers in the foundry industry are exposed to hazardous chemical agents such as metal fumes, gases, vapor of molten metal, and respirable dust and hazardous physical agents such as heat, noise, and electromagnetic fields. Co-exposures to hazardous physical and chemical agents in foundry workplaces may cause DNA damage in workers. This study aimed to evaluate DNA damage in foundry workers. Thirty-three exposed foundry workers as a exposure groups and 33 non-exposed individuals as a control groups participated in this study. Buccal micronucleus cytome (BMCyt assay) assay was used to assess DNA damage. Results showed that foundry workers were under exposure to hazardous chemical and physical agents such as metal fumes and noise. The percentage of micronucleus (MN) cells in exposure group (0.59 ± 0.93 %) were statistically higher than control group (0.23 ± 0.23 %) (P < 0.05) %). Also, the percentage of nuclear bud cells and binucleated cells in exposure group were statistically higher than control group (P < 0.05). The percentage of differentiated normal cells were significantly higher in the control group compared to the exposed group (P < 0.05). Foundry workers are at risk of DNA damage; therefore, prevention measures need to be implemented to reduce exposure to air pollutants in foundry workplaces.
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Affiliation(s)
| | - Yahya Rasoulzadeh
- Road Traffic Injury Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Department of Occupational Health Engineering, Faculty of Health, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Yousef Mohammadian
- Department of Occupational Health Engineering, Faculty of Health, Tabriz University of Medical Sciences, Tabriz, Iran.
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2
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Howlett P, Mousa H, Said B, Mbuya A, Kon OM, Mpagama S, Feary J. Silicosis, tuberculosis and silica exposure among artisanal and small-scale miners: A systematic review and modelling paper. PLOS GLOBAL PUBLIC HEALTH 2023; 3:e0002085. [PMID: 37733799 PMCID: PMC10513209 DOI: 10.1371/journal.pgph.0002085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Accepted: 08/30/2023] [Indexed: 09/23/2023]
Abstract
An estimated 44 million artisanal and small-scale miners (ASM), largely based in developing economies, face significant occupational risks for respiratory diseases which have not been reviewed. We therefore aimed to review studies that describe silicosis and tuberculosis prevalence and respirable crystalline silica (RCS) exposures among ASM and use background evidence to better understand the relationship between exposures and disease outcomes. We searched PubMed, Web of Science, Scopus and Embase for studies published before the 24th March 2023. Our primary outcome of interest was silicosis or tuberculosis among ASM. Secondary outcomes included measurements of respirable dust or silica, spirometry and prevalence of respiratory symptoms. A systematic review and narrative synthesis was performed and risk of bias assessed using the Joanna Briggs Prevalence Critical Appraisal Tool. Logistic and Poisson regression models with predefined parameters were used to estimate silicosis prevalence and tuberculosis incidence at different distributions of cumulative silica exposure. We identified 18 eligible studies that included 29,562 miners from 13 distinct populations in 10 countries. Silicosis prevalence ranged from 11 to 37%, despite four of five studies reporting an average median duration of mining of <6 years. Tuberculosis prevalence was high; microbiologically confirmed disease ranged from 1.8 to 6.1% and clinical disease 3.0 to 17%. Average RCS intensity was very high (range 0.19-89.5 mg/m3) and respiratory symptoms were common. Our modelling demonstrated decreases in cumulative RCS are associated with reductions in silicosis and tuberculosis, with greater reductions at higher mean exposures. Despite potential selection and measurement bias, prevalence of silicosis and tuberculosis were high in the studies identified in this review. Our modelling demonstrated the greatest respiratory health benefits of reducing RCS are in those with highest exposures. ASM face a high occupational respiratory disease burden which can be reduced by low-cost and effective reductions in RCS.
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Affiliation(s)
- Patrick Howlett
- National Heart & Lung Institute, Imperial College London, London, United Kingdom
| | - Hader Mousa
- Centre for Occupational and Environmental Health, Kigali, Rwanda
| | - Bibie Said
- Kibong’oto Infectious Disease Hospital, Kilimanjaro, Tanzania
| | - Alexander Mbuya
- Kibong’oto Infectious Disease Hospital, Kilimanjaro, Tanzania
| | - Onn Min Kon
- National Heart & Lung Institute, Imperial College London, London, United Kingdom
| | - Stellah Mpagama
- Kibong’oto Infectious Disease Hospital, Kilimanjaro, Tanzania
| | - Johanna Feary
- National Heart & Lung Institute, Imperial College London, London, United Kingdom
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Andersson L, Hedbrant A, Bryngelsson IL, Vihlborg P, Särndahl E, Westberg H. Silica Exposure and Cardiovascular, Cerebrovascular, and Respiratory Morbidity in a Cohort of Male Swedish Iron Foundry Workers. J Occup Environ Med 2023; 65:731-739. [PMID: 37311079 PMCID: PMC10487371 DOI: 10.1097/jom.0000000000002890] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
OBJECTIVE We present quantitative exposure-response data on silica exposure in male Swedish iron foundry workers for cardiovascular, cerebrovascular, and respiratory morbidity. METHODS This research is a cohort study of 2063 male Swedish iron foundry workers. From the Swedish National Patient Registers, data on morbidity incidence were retrieved. A historical measurement database of 1667 respirable silica exposure measurements from 10 Swedish iron foundries was used to calculate the cumulative exposure dose for each worker. RESULTS Increased morbidity risk for the whole group of foundry workers was determined for ischemic heart disease, cerebrovascular disease, chronic obstructive pulmonary disease (COPD), bronchitis, and pneumonia. In addition, an increased risk for COPD at cumulative silica exposures ranging from 0.11 to 0.84 mg/m 3 year is presented. CONCLUSIONS The study presents a significantly increased COPD risk at cumulative silica exposures below the Swedish occupational exposure limit.
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An Increase in Plasma Adipsin Levels Is Associated With Higher Cumulative Dust Exposure and Airway Obstruction in Foundry Workers. J Occup Environ Med 2023; 65:203-209. [PMID: 36730948 DOI: 10.1097/jom.0000000000002736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE The aim of the study was to assess whether plasma adipokine levels (adipsin, adiponectin, leptin, and resistin) are associated with pulmonary function in foundry workers. METHODS We examined 65 dust-exposed foundry workers and 40 nonexposed controls and analyzed their lung function and plasma adipokine levels at baseline and after approximately 7 years of follow-up. RESULTS A higher increase in plasma adipsin was associated with the development of airway obstruction in exposed subjects during follow-up after adjusting for body mass index changes during the follow-up period. Furthermore, the increase in adipsin levels was positively associated with cumulative dust exposure even after adjusting for smoking and body mass index changes during follow-up ( P = 0.015). CONCLUSION The results suggest that plasma adipsin is involved in the pathogenesis of subclinical airway inflammation and the development of chronic obstruction and is induced by occupational dust exposure.
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5
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Progressive Massive Fibrosis Risk Factors. J Occup Environ Med 2022; 64:557-561. [DOI: 10.1097/jom.0000000000002545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Sex-Related Differences in the Risk of Silicosis Among Chinese Pottery Workers: A Cohort Study. J Occup Environ Med 2021; 63:74-79. [PMID: 33122539 DOI: 10.1097/jom.0000000000002068] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES To investigate the effect of sex on the risk of silicosis and to explore any interaction between cigarette smoking and sex in the development of silicosis. METHODS The cohort was selected from eight Chinese pottery factories. Diagnoses of silicosis were based on 1986 Chinese pneumoconiosis Roentgen diagnostic criteria. Data on cigarette smoking were collected by face-to-face interviews in 1989 and 2003. RESULTS Eight thousand eight hundred and eighty seven dust-exposed workers were included. Men had a 77% higher incidence of silicosis than women. At lower pack-years of smoking, men were 72% more at risk than women. The latency period was found to be longest in female never-smokers and shortest in female ever-smokers. CONCLUSIONS Men had a higher risk of developing silicosis than women. Cigarette smoking increased the risk in both sexes, more so in women.
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Koskela K, Riitta S, Panu O, Jukka U, Eeva M, Lauri L. High alveolar nitric oxide is associated with steeper lung function decline in foundry workers. J Breath Res 2021; 15. [PMID: 33770784 DOI: 10.1088/1752-7163/abf272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 03/26/2021] [Indexed: 11/12/2022]
Abstract
Occupational dust exposure induces inflammatory responses that often precede the onset of clinical disease. Inflammation in the peripheral part of the lung can be demonstrated by measuring the alveolar NO concentration (CANO) in exhaled breath. The aim of the study was to assess whether cumulative dust exposure affects the change in CANO during follow-up and whether baseline CANO can predict an impairment in lung function during follow-up in foundry workers. We examined 74 dust-exposed and 42 nonexposed foundry workers and measured CANO and lung function at baseline and after 7 years of follow-up. An increase in CANO during the follow-up period was positively associated with cumulative dust exposure in foundry work (p= 0.035). Furthermore, a higher baseline CANO was associated with an accelerated decline in the forced vital capacity (FVC) during the follow-up period (absolute decrease in FVCp= 0.021, relative decrease in FVCp= 0.017). Higher cumulative dust exposure in foundry work is associated with a greater increase in CANO during follow-up, suggesting ongoing pulmonary inflammation in these subjects. Importantly, a high baseline CANO is associated with an accelerated decline in lung function, suggesting that CANO measurements might serve as a screening tool for high-risk workers.
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Affiliation(s)
- Kirsi Koskela
- Finnish Institute of Occupational Health, PO Box 486, FI-33101 Tampere, Finland.,The Outpatient Clinic of Occupational Medicine, Tampere University Hospital, Tampere, Finland
| | - Sauni Riitta
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Oksa Panu
- Finnish Institute of Occupational Health, PO Box 486, FI-33101 Tampere, Finland
| | - Uitti Jukka
- Finnish Institute of Occupational Health, PO Box 486, FI-33101 Tampere, Finland.,Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Moilanen Eeva
- The Immunopharmacology Research Group, Faculty of Medicine and Health Technology, Tampere University, and Tampere University Hospital, Tampere, Finland
| | - Lehtimäki Lauri
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland.,Allergy Centre, Tampere University Hospital, Tampere, Finland
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Abstract
This overview provides an update on silicosis epidemiology with review of exposures and emerging trends in acute and accelerated silicosis in the twenty-first century. The silicosis epidemics in mining, denim sandblasting, and engineering stone industries are highlighted. Clinical presentations of silicosis and silica-related conditions such as autoimmune, kidney, and mycobacterial disease, as well as lung cancer, are discussed. Important aspects of the new OSHA 2017 Silica Standard are presented. This review also includes practical guidance for clinicians to address questions that may arise when evaluating silica-exposed patients and to the public health responses needed following a diagnosis of silica-related disease.
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Affiliation(s)
- Silpa Krefft
- Division of Environmental and Occupational Health Sciences, National Jewish Health, 1400 Jackson Street, Denver, CO 80206, USA; Division of Pulmonary and Critical Care Medicine, VA Eastern Colorado Health Care System, Aurora, CO, USA; Division of Pulmonary and Critical Care Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA; Department of Environmental and Occupational Health, Colorado School of Public Health, Aurora, CO, USA.
| | - Jenna Wolff
- Division of Environmental and Occupational Health Sciences, National Jewish Health, 1400 Jackson Street, Denver, CO 80206, USA
| | - Cecile Rose
- Division of Environmental and Occupational Health Sciences, National Jewish Health, 1400 Jackson Street, Denver, CO 80206, USA; Division of Pulmonary and Critical Care Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA; Department of Environmental and Occupational Health, Colorado School of Public Health, Aurora, CO, USA
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9
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James E, Linde B, Redlich CA. Master Clinician and Public Health Practitioner: Selected Occupational and Environmental Pulmonary Cases. Clin Chest Med 2021; 41:567-580. [PMID: 33153680 DOI: 10.1016/j.ccm.2020.08.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Occupational and environmental exposures contribute to the development and progression of most lung diseases, yet their impact is greatly under-recognized in clinical practice. Clinicians caring for patients with respiratory diseases should maintain a high index of suspicion for occupational and environmental contributing factors. Mastering occupational and environmental medicine clinical decision making requires specialized clinical skills. These skills include obtaining an appropriate work and exposure history; making an assessment of the magnitude and relevance of exposures and their contribution to a patient's respiratory disease; utilizing appropriate resources for evaluation and management of exposure-related disease; and considering socioeconomic and public health factors.
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Affiliation(s)
- Efia James
- Department of Medicine, Yale Occupational and Environmental Medicine Program, Yale School of Medicine, 367 Cedar Street, ESHA 2nd Floor, New Haven, CT 06510, USA.
| | - Brian Linde
- Department of Medicine, Yale Occupational and Environmental Medicine Program, Yale School of Medicine, 367 Cedar Street, ESHA 2nd Floor, New Haven, CT 06510, USA
| | - Carrie A Redlich
- Department of Medicine, Yale Occupational and Environmental Medicine Program, Yale School of Medicine, 367 Cedar Street, ESHA 2nd Floor, New Haven, CT 06510, USA
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10
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Wang D, Zhou M, Liu Y, Ma J, Yang M, Shi T, Chen W. Comparison of Risk of Silicosis in Metal Mines and Pottery Factories. Chest 2020; 158:1050-1059. [DOI: 10.1016/j.chest.2020.03.054] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Revised: 03/16/2020] [Accepted: 03/19/2020] [Indexed: 11/27/2022] Open
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Andersson L, Bryngelsson IL, Hedbrant A, Persson A, Johansson A, Ericsson A, Lindell I, Stockfelt L, Särndahl E, Westberg H. Respiratory health and inflammatory markers - Exposure to respirable dust and quartz and chemical binders in Swedish iron foundries. PLoS One 2019; 14:e0224668. [PMID: 31675355 PMCID: PMC6824619 DOI: 10.1371/journal.pone.0224668] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 10/19/2019] [Indexed: 01/13/2023] Open
Abstract
Purpose To study the relationship between respirable dust, quartz and chemical binders in Swedish iron foundries and respiratory symptoms, lung function (as forced expiratory volume FEV1 and vital capacity FVC), fraction of exhaled nitric oxide (FENO) and levels of club cell secretory protein 16 (CC16) and CRP. Methods Personal sampling of respirable dust and quartz was performed for 85 subjects in three Swedish iron foundries. Full shift sampling and examination were performed on the second or third day of a working week after a work free weekend, with additional sampling on the fourth or fifth day. Logistic, linear and mixed model analyses were performed including, gender, age, smoking, infections, sampling day, body mass index (BMI) and chemical binders as covariates. Results The adjusted average respirable quartz and dust concentrations were 0.038 and 0.66 mg/m3, respectively. Statistically significant increases in levels of CC16 were associated with exposure to chemical binders (p = 0.05; p = 0.01) in the regression analysis of quartz and respirable dust, respectively. Non-significant exposure-responses were identified for cumulative quartz and the symptoms asthma and breathlessness. For cumulative chemical years, non-significant exposure–response were observed for all but two symptoms. FENO also exhibited a non significant exposure-response for both quartz and respirable dust. No exposure-response was determined for FEV1 or FVC, CRP and respirable dust and quartz. Conclusions Our findings suggest that early markers of pulmonary effect, such as increased levels of CC16 and FENO, are more strongly associated with chemical binder exposure than respirable quartz and dust in foundry environments.
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Affiliation(s)
- Lena Andersson
- Department of Occupational and Environmental Medicine, Faculty of Medicine and Health, Örebro University, Örebro, Sweden
- Department of Medical Sciences, School of Medicine and Health, Örebro University, Örebro, Sweden
- * E-mail:
| | - Ing-Liss Bryngelsson
- Department of Occupational and Environmental Medicine, Faculty of Medicine and Health, Örebro University, Örebro, Sweden
| | - Alexander Hedbrant
- Department of Medical Sciences, School of Medicine and Health, Örebro University, Örebro, Sweden
- Inflammatory Response and Infection Susceptibility Centre (iRiSC), Örebro University, Örebro, Sweden
| | - Alexander Persson
- Department of Medical Sciences, School of Medicine and Health, Örebro University, Örebro, Sweden
- Inflammatory Response and Infection Susceptibility Centre (iRiSC), Örebro University, Örebro, Sweden
| | - Anders Johansson
- Department of Occupational and Environmental Medicine, Faculty of Medicine and Health, Örebro University, Örebro, Sweden
| | - Annette Ericsson
- Department of Occupational and Environmental Medicine, Faculty of Medicine and Health, Örebro University, Örebro, Sweden
| | - Ina Lindell
- Department of Occupational and Environmental Medicine, Faculty of Medicine and Health, Örebro University, Örebro, Sweden
| | - Leo Stockfelt
- Unit of Occupational and Environmental Medicine, Sahlgrenska Academy, University of Gothenburg and Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Eva Särndahl
- Department of Medical Sciences, School of Medicine and Health, Örebro University, Örebro, Sweden
- Inflammatory Response and Infection Susceptibility Centre (iRiSC), Örebro University, Örebro, Sweden
| | - Håkan Westberg
- Department of Occupational and Environmental Medicine, Faculty of Medicine and Health, Örebro University, Örebro, Sweden
- Department of Medical Sciences, School of Medicine and Health, Örebro University, Örebro, Sweden
- Inflammatory Response and Infection Susceptibility Centre (iRiSC), Örebro University, Örebro, Sweden
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Tong R, Cheng M, Ma X, Yang Y, Liu Y, Li J. Quantitative health risk assessment of inhalation exposure to automobile foundry dust. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2019; 41:2179-2193. [PMID: 30874937 DOI: 10.1007/s10653-019-00277-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 03/05/2019] [Indexed: 06/09/2023]
Abstract
With a growing awareness of environmental protection, the dust pollution caused by automobile foundry work has become a serious and urgent problem. This study aimed to explore contamination levels and health effects of automobile foundry dust. A total of 276 dust samples from six types of work in an automobile foundry factory were collected and analysed using the filter membrane method. Probabilistic risk assessment model was developed for evaluating the health risk of foundry dust on workers. The health risk and its influencing factors among workers were then assessed by applying the Monte Carlo method to identify the most significant parameters. Health damage assessment was conducted to translate health risk into disability-adjusted life year (DALY). The results revealed that the mean concentration of dust on six types of work ranged from 1.67 to 5.40 mg/m3. The highest health risks to be come from melting, cast shakeout and finishing, followed by pouring, sand preparation, moulding and core-making. The probability of the risk exceeding 10-6 was approximately 85%, 90%, 90%, 75%, 70% and 45%, respectively. The sensitivity analysis indicated that average time, exposure duration, inhalation rate and dust concentration (C) made great contribution to dust health risk. Workers exposed to cast shakeout and finishing had the largest DALY of 48.64a. These results can further help managers to fully understand the dust risks on various types of work in the automobile foundry factories and provide scientific basis for the management and decision-making related to health damage assessment.
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Affiliation(s)
- Ruipeng Tong
- School of Emergency Management and Safety Engineering, China University of Mining and Technology (Beijing), D11, Xueyuan Road, Haidian District, Beijing, 100083, China.
| | - Mengzhao Cheng
- School of Emergency Management and Safety Engineering, China University of Mining and Technology (Beijing), D11, Xueyuan Road, Haidian District, Beijing, 100083, China
| | - Xiaofei Ma
- School of Emergency Management and Safety Engineering, China University of Mining and Technology (Beijing), D11, Xueyuan Road, Haidian District, Beijing, 100083, China
| | - Yunyun Yang
- School of Emergency Management and Safety Engineering, China University of Mining and Technology (Beijing), D11, Xueyuan Road, Haidian District, Beijing, 100083, China
| | - Yafei Liu
- Baic Motor Corporation, Ltd., Baic Group, Beijing, 101300, China
| | - Jianfeng Li
- School of Environment, Guangzhou Key Laboratory of Environmental Exposure and Health, and Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, B1071, XingYe Avenue 855, Panyu District, Guangzhou, 510632, Guangdong, China.
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13
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Westberg H, Hedbrant A, Persson A, Bryngelsson IL, Johansson A, Ericsson A, Sjögren B, Stockfelt L, Särndahl E, Andersson L. Inflammatory and coagulatory markers and exposure to different size fractions of particle mass, number and surface area air concentrations in Swedish iron foundries, in particular respirable quartz. Int Arch Occup Environ Health 2019; 92:1087-1098. [PMID: 31165309 PMCID: PMC6814634 DOI: 10.1007/s00420-019-01446-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 05/28/2019] [Indexed: 01/06/2023]
Abstract
Purpose To study the relationship between inhalation of airborne particles and quartz in Swedish iron foundries and markers of inflammation and coagulation in blood. Methods Personal sampling of respirable dust and quartz was performed for 85 subjects in three Swedish iron foundries. Stationary measurements were used to study the concentrations of respirable dust and quartz, inhalable and total dust, PM10 and PM2.5, as well as the particle surface area and the particle number concentrations. Markers of inflammation, namely interleukins (IL-1β, IL-6, IL-8, IL-10 and IL-12), C-reactive protein, and serum amyloid A (SAA) were measured in plasma or serum, together with markers of coagulation including fibrinogen, factor VIII (FVIII), von Willebrand factor and d-dimer. Complete sampling was performed on the second or third day of a working week after a work-free weekend, and follow-up samples were collected 2 days later. A mixed model analysis was performed including sex, age, smoking, infections, blood group, sampling day and BMI as covariates. Results The average 8-h time-weighted average air concentrations of respirable dust and quartz were 0.85 mg/m3 and 0.052 mg/m3, respectively. Participants in high-exposure groups with respect to some of the measured particle types exhibited significantly elevated levels of SAA, fibrinogen and FVIII. Conclusions These observed relationships between particle exposure and inflammatory markers may indicate an increased risk of cardiovascular disease among foundry workers with high particulate exposure.
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Affiliation(s)
- Håkan Westberg
- Department of Occupational and Environmental Medicine, Faculty of Medicine and Health, Örebro University, 70182, Örebro, Sweden. .,Department of Medical Sciences, School of Medicine and Health, Örebro University, 701 82, Örebro, Sweden. .,Inflammatory Response and Infection Susceptibility Centre (iRiSC), Örebro University, 701 82, Örebro, Sweden. .,Department of Occupational and Environmental Medicine, Örebro University Hospital, 701 85, Örebro, Sweden.
| | - Alexander Hedbrant
- Department of Medical Sciences, School of Medicine and Health, Örebro University, 701 82, Örebro, Sweden.,Inflammatory Response and Infection Susceptibility Centre (iRiSC), Örebro University, 701 82, Örebro, Sweden
| | - Alexander Persson
- Department of Medical Sciences, School of Medicine and Health, Örebro University, 701 82, Örebro, Sweden.,Inflammatory Response and Infection Susceptibility Centre (iRiSC), Örebro University, 701 82, Örebro, Sweden
| | - Ing-Liss Bryngelsson
- Department of Occupational and Environmental Medicine, Faculty of Medicine and Health, Örebro University, 70182, Örebro, Sweden
| | - Anders Johansson
- Department of Occupational and Environmental Medicine, Faculty of Medicine and Health, Örebro University, 70182, Örebro, Sweden
| | - Annette Ericsson
- Department of Occupational and Environmental Medicine, Faculty of Medicine and Health, Örebro University, 70182, Örebro, Sweden
| | - Bengt Sjögren
- Work Environment Toxicology, Institute of Environmental Medicine, Karolinska Institutet, 171 77, Stockholm, Sweden
| | - Leo Stockfelt
- Department of Occupational and Environmental Medicine, University of Gothenburg, PB 414, 405 30, Göteborg, Sweden
| | - Eva Särndahl
- Department of Medical Sciences, School of Medicine and Health, Örebro University, 701 82, Örebro, Sweden.,Inflammatory Response and Infection Susceptibility Centre (iRiSC), Örebro University, 701 82, Örebro, Sweden
| | - Lena Andersson
- Department of Occupational and Environmental Medicine, Faculty of Medicine and Health, Örebro University, 70182, Örebro, Sweden.,Department of Medical Sciences, School of Medicine and Health, Örebro University, 701 82, Örebro, Sweden
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Wong JYY, Bassig BA, Seow WJ, Hu W, Ji BT, Blair A, Silverman DT, Lan Q. Lung cancer risk in welders and foundry workers with a history of heavy smoking in the USA: The National Lung Screening Trial. Occup Environ Med 2017; 74:440-448. [PMID: 28069970 PMCID: PMC6400285 DOI: 10.1136/oemed-2016-104168] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Revised: 11/30/2016] [Accepted: 12/19/2016] [Indexed: 12/27/2022]
Abstract
OBJECTIVES Foundry work is a risk factor for lung cancer; however, the association with welding is unclear, as smoking is common among metalworkers and may mask the relationship. We evaluated whether history of welding and foundry work, independently and jointly, and employment duration were associated with lung cancer risk in heavy smokers. METHODS We analysed data from the National Lung Screening Trial, a prospective randomised trial of 53 454 heavy smokers (>30 pack-years) in the USA. Cox regression models were used to estimate the HRs and 95% CIs of medically/histologically confirmed incident lung cancer during the follow-up period (2002-2009) in relation to history and duration of welding and foundry work assessed via questionnaires, adjusted for screening arm, component study, sex, age, race/ethnicity, education, smoking status and pack-years, body mass index and personal/family medical history. RESULTS There were 2034 incident lung cancer cases throughout the follow-up. Increasing years of employment in welding (p-trend =0.039) and foundry work (p-trend =0.005) were related to increased lung cancer risk among heavy smokers. Having ever been employed (≥1 yr) as either a welder or foundry worker alone was associated with non-significant increased risks of lung cancer (HR=1.12 (95% CI 0.91 to 1.37) and HR=1.09 (95% CI 0.85 to 1.39), respectively). Further, there was a joint-effect in that those who were ever employed in both occupations had significantly increased risks (HR=1.48 (95% CI 1.08 to 2.04)). CONCLUSIONS Our findings provide further evidence that exposure to welding/metal fumes may be associated with elevated lung cancer risk. TRIAL REGISTRATION NUMBER NCT00047385.
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Affiliation(s)
- Jason Y Y Wong
- Division of Cancer Epidemiology and Genetics, Occupational and Environmental Epidemiology Branch, National Cancer Institute, Rockville, Maryland, USA
| | - Bryan A Bassig
- Division of Cancer Epidemiology and Genetics, Occupational and Environmental Epidemiology Branch, National Cancer Institute, Rockville, Maryland, USA
| | - Wei Jie Seow
- Division of Cancer Epidemiology and Genetics, Occupational and Environmental Epidemiology Branch, National Cancer Institute, Rockville, Maryland, USA
| | - Wei Hu
- Division of Cancer Epidemiology and Genetics, Occupational and Environmental Epidemiology Branch, National Cancer Institute, Rockville, Maryland, USA
| | - Bu-Tian Ji
- Division of Cancer Epidemiology and Genetics, Occupational and Environmental Epidemiology Branch, National Cancer Institute, Rockville, Maryland, USA
| | - Aaron Blair
- Division of Cancer Epidemiology and Genetics, Occupational and Environmental Epidemiology Branch, National Cancer Institute, Rockville, Maryland, USA
| | - Debra T Silverman
- Division of Cancer Epidemiology and Genetics, Occupational and Environmental Epidemiology Branch, National Cancer Institute, Rockville, Maryland, USA
| | - Qing Lan
- Division of Cancer Epidemiology and Genetics, Occupational and Environmental Epidemiology Branch, National Cancer Institute, Rockville, Maryland, USA
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Hoet P, Desvallées L, Lison D. Do current OELs for silica protect from obstructive lung impairment? A critical review of epidemiological data. Crit Rev Toxicol 2017; 47:650-677. [DOI: 10.1080/10408444.2017.1315363] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Perrine Hoet
- Louvain Center for Toxicology and Applied Pharmacology (LTAP), Institute of Experimental and Clinical Research (IREC), Université Catholique de Louvain, Bruxelles, Belgium
| | - Laure Desvallées
- Louvain Center for Toxicology and Applied Pharmacology (LTAP), Institute of Experimental and Clinical Research (IREC), Université Catholique de Louvain, Bruxelles, Belgium
| | - Dominique Lison
- Louvain Center for Toxicology and Applied Pharmacology (LTAP), Institute of Experimental and Clinical Research (IREC), Université Catholique de Louvain, Bruxelles, Belgium
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Do sanitary ceramic workers have a worse presentation of chest radiographs or pulmonary function tests than other ceramic workers? J Formos Med Assoc 2017; 116:139-144. [PMID: 27965042 DOI: 10.1016/j.jfma.2016.10.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2016] [Revised: 10/25/2016] [Accepted: 10/30/2016] [Indexed: 11/21/2022] Open
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Hammond DR, Shulman SA, Echt AS. Respirable crystalline silica exposures during asphalt pavement milling at eleven highway construction sites. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2016; 13:538-48. [PMID: 26913983 PMCID: PMC4915055 DOI: 10.1080/15459624.2016.1153803] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Asphalt pavement milling machines use a rotating cutter drum to remove the deteriorated road surface for recycling. The removal of the road surface has the potential to release respirable crystalline silica, to which workers can be exposed. This article describes an evaluation of respirable crystalline silica exposures to the operator and ground worker from two different half-lane and larger asphalt pavement milling machines that had ventilation dust controls and water-sprays designed and installed by the manufacturers. Manufacturer A completed milling for 11 days at 4 highway construction sites in Wisconsin, and Manufacturer B completed milling for 10 days at 7 highway construction sites in Indiana. To evaluate the dust controls, full-shift personal breathing zone air samples were collected from an operator and ground worker during the course of normal employee work activities of asphalt pavement milling at 11 different sites. Forty-two personal breathing zone air samples were collected over 21 days (sampling on an operator and ground worker each day). All samples were below 50 µg/m(3) for respirable crystalline silica, the National Institute for Occupational Safety and Health recommended exposure limit. The geometric mean personal breathing zone air sample was 6.2 µg/m(3) for the operator and 6.1 µg/m(3) for the ground worker for the Manufacturer A milling machine. The geometric mean personal breathing zone air sample was 4.2 µg/m(3) for the operator and 9.0 µg/m(3) for the ground worker for the Manufacturer B milling machine. In addition, upper 95% confidence limits for the mean exposure for each occupation were well below 50 µg/m(3) for both studies. The silica content in the bulk asphalt material being milled ranged from 7-23% silica for roads milled by Manufacturer A and from 5-12% silica for roads milled by Manufacturer B. The results indicate that engineering controls consisting of ventilation controls in combination with water-sprays are capable of controlling occupational exposures to respirable crystalline silica generated by asphalt pavement milling machines on highway construction sites.
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Affiliation(s)
- Duane R. Hammond
- Division of Applied Research and Technology, Engineering and Physical Hazards Branch, National Institute for Occupational Safety and Health
| | - Stanley A. Shulman
- Division of Applied Research and Technology, Engineering and Physical Hazards Branch, National Institute for Occupational Safety and Health
| | - Alan S. Echt
- Division of Applied Research and Technology, Engineering and Physical Hazards Branch, National Institute for Occupational Safety and Health
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Rocha LF, Luppino Assad AP, Marangoni RG, Del Rio APT, Marques-Neto JF, Sampaio-Barros PD. Systemic sclerosis and silica exposure: a rare association in a large Brazilian cohort. Rheumatol Int 2016; 36:697-702. [DOI: 10.1007/s00296-015-3412-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 12/18/2015] [Indexed: 11/29/2022]
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Abstract
OBJECTIVE To assess whether cumulative dust exposure in foundry work is associated with airway inflammation measured by the analysis of fractionated exhaled nitric oxide (NO) concentration, or by inflammatory markers in exhaled breath condensate or serum. METHODS We examined 476 dust-exposed and nonexposed foundry workers, and assessed the individual cumulative exposure to dusts and respirable quartz. Bronchial and alveolar NO production and inflammatory markers in exhaled breath condensate and in serum samples were also analyzed. RESULTS After adjusting for pack-years of smoking, increased levels of alveolar NO, serum C-reactive protein, and interleukin-8 were associated with a higher level of cumulative exposure to dust. The referents had higher serum myeloperoxidase levels, bronchial NO output, and 8-isoprostane levels in exhaled breath condensate than in the dust-exposed groups. CONCLUSIONS Dust exposure in foundry work may induce both systemic and alveolar inflammation.
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Healy CB, Coggins MA, Van Tongeren M, MacCalman L, McGowan P. An evaluation of on-tool shrouds for controlling respirable crystalline silica in restoration stone work. ACTA ACUST UNITED AC 2014; 58:1155-67. [PMID: 25261456 DOI: 10.1093/annhyg/meu069] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVES The task of grinding sandstone with a 5-inch angle grinder is a major source of exposure to respirable crystalline silica (RCS), known to cause diseases such as silicosis and lung cancer among workers who work with these materials. A shroud may be a suitable engineering control for this task. The objectives of this study were to evaluate the effectiveness of four commercially available shrouds at reducing respirable dust and RCS levels during the task of grinding sandstone using tools and accessories typical of restoration stone work. METHODS The task of grinding sandstone with a 5-inch angle grinder, equipped with different grinding wheels, was carried out over three trials at a restoration stone masonry site. Photometric and RCS data were collected when a 5-inch grinder, equipped with different grinding wheels, was used to grind sandstone with and without a shroud. A total of 24 short duration samples were collected for each no shroud and with shroud combination. Worker feedback on the practicalities of each shroud evaluated was also collected. RESULTS Respirable dust concentrations and RCS were both significantly lower (P < 0.001) when the grinders were equipped with a shroud compared with grinders without a shroud. Total geometric mean (GM) photometric respirable dust levels measured when grinding with a shroud were 0.5 mg m(-3), a reduction of 92% compared to grinding without a shroud (7.1 mg m(-3)). The overall GM RCS concentrations were reduced by the use of a shroud by 99%. GM photometric exposure levels were highest when using the Hilti 5-inch diamond grinding cup and Diamond turbo cup and lowest when using the Corundum grinding point. CONCLUSIONS Concentrations of respirable dust and RCS can be significantly reduced by using commercially available shrouds while grinding sandstone with a 5-inch angle grinder in restoration stonework. The short-term photometric respirable dust and RCS measurements collected with and without a shroud indicate that dust and RCS concentrations are reduced by between 90 and 99%. Supplemental exposure controls such as respiratory protective equipment would be required to reduce worker 8-h time-weighted average RCS exposure to below the Scientific Committee on Occupational Exposure Limits recommended occupational exposure limit value of 0.05 mg m(-3) and the American Conference of Governmental Industrial Hygienists threshold limit value of 0.025 mg m(-3).
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Affiliation(s)
- Catherine B Healy
- 1.School of Physics, National University of Ireland, Galway, Ireland
| | - Marie A Coggins
- 1.School of Physics, National University of Ireland, Galway, Ireland
| | - Martie Van Tongeren
- 2.Institute of Occupational Medicine, Research Avenue North, Riccarton, Edinburgh EH14 4AP, UK
| | - Laura MacCalman
- 2.Institute of Occupational Medicine, Research Avenue North, Riccarton, Edinburgh EH14 4AP, UK
| | - Padraic McGowan
- 3.Irish Commissioners for Public Works, Jonathan Swift Street, Trim, Co Meath, Ireland
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Healy CB, Coggins MA, Van Tongeren M, MacCalman L, McGowan P. Determinants of respirable crystalline silica exposure among stoneworkers involved in stone restoration work. ACTA ACUST UNITED AC 2013; 58:6-18. [PMID: 23997236 DOI: 10.1093/annhyg/met045] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVES Crystalline silica occurs as a significant component of many traditional materials used in restoration stonework, and stoneworkers who work with these materials are potentially exposed to stone dust containing respirable crystalline silica (RCS). Exposure to RCS can result in the development of a range of adverse health effects, including silicosis and lung cancer. An understanding of the determinants of RCS exposure is important for selecting appropriate exposure controls and in preventing occupational diseases. The objectives of this study were to quantify the RCS exposure of stoneworkers involved in the restoration and maintenance of heritage properties and to identify the main determinants of RCS exposure among this occupational group. METHODS An exposure assessment was carried out over a 3-year period amongst a group of stonemasons and stone cutters involved in the restoration and maintenance of heritage buildings in Ireland. Personal air samples (n = 103) with corresponding contextual information were collected. Exposure data were analysed using mixed-effects modelling to investigate determinants of RCS exposure and their contribution to the individual's mean exposure. Between-depot, between-worker, and within-worker variance components were also investigated. RESULTS The geometric mean (GM) RCS exposure concentrations for all tasks measured ranged from <0.02 to 0.70mg m(-3). GM RCS exposure concentrations for work involving limestone and lime mortar were <0.02-0.01mg m(-3), tasks involving granite were 0.01-0.06mg m(-3), and tasks involving sandstone were <0.02-0.70mg m(-3). Sixty-seven percent of the 8-h time-weighted average (TWA) exposure measurements for tasks involving sandstone exceeded the Scientific Committee on Occupational Exposure Limits recommended occupational exposure limit value of 0.05mg m(-3). Highest RCS exposure values were recorded for the tasks of grinding (GM = 0.70mg m(-3)) and cutting (GM = 0.70mg m(-3)) sandstone. In the mixed-effects analyses, task was found to be significantly associated with RCS exposure, with the tasks of grinding and cutting resulting in average exposures of between 32 and 70 times the exposures recorded for the task of stone decorating. The between-depot, between-worker, and within-worker variance components were reduced by 46, 89, and 49%, respectively, after including task in the mixed effects model. CONCLUSIONS Restoration stoneworkers are regularly overexposed (compared with 0.1 and 0.05mg m(-3) 8-h TWA) to RCS dust when working with sandstone. The results indicate that the tasks of cutting and grinding sandstone are predictors of increased exposure to RCS dust. In order to decrease exposure to RCS, efforts should be focused on developing and implementing interventions which focus on these high-risk tasks.
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Mossman BT, Glenn RE. Bioreactivity of the crystalline silica polymorphs, quartz and cristobalite, and implications for occupational exposure limits (OELs). Crit Rev Toxicol 2013; 43:632-60. [PMID: 23863112 DOI: 10.3109/10408444.2013.818617] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Silica or silicon dioxides (SiO₂) are naturally occurring substances that comprise the vast majority of the earth's crust. Because of their prevalence and commercial applications, they have been widely studied for their potential to induce pulmonary fibrosis and other disorders. Historically, the focus in the workplace has been on the development of inflammation and fibrotic lung disease, the basis for promulgating workplace standards to protect workers. Crystalline silica (CS) polymorphs, predominantly quartz and cristobalite, are used in industry but are different in their mineralogy, chemistry, surface features, size dimensions and association with other elements naturally and during industrial applications. Epidemiologic, clinical and experimental studies in the literature historically have predominantly focused on quartz polymorphs. Thus, in this review, we summarize past scientific evaluations and recent peer-reviewed literature with an emphasis on cristobalite, in an attempt to determine whether quartz and cristobalite polymorphs differ in their health effects, toxicity and other properties that may dictate the need for various standards of protection in the workplace. In addition to current epidemiological and clinical reports, we review in vivo studies in rodents as well as cell culture studies that shed light on mechanisms intrinsic to the toxicity, altered cell responses and protective or defense mechanisms in response to these minerals. The medical and scientific literature indicates that the mechanisms of injury and potential causation of inflammation and fibrotic lung disease are similar for quartz and cristobalite. Our analysis of these data suggests similar occupational exposure limits (OELs) for these minerals in the workplace.
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Affiliation(s)
- Brooke T Mossman
- Department of Pathology, University of Vermont College of Medicine, Burlington, VT 05405-0068, USA.
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Esswein EJ, Breitenstein M, Snawder J, Kiefer M, Sieber WK. Occupational exposures to respirable crystalline silica during hydraulic fracturing. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2013; 10:347-356. [PMID: 23679563 DOI: 10.1080/15459624.2013.788352] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
This report describes a previously uncharacterized occupational health hazard: work crew exposures to respirable crystalline silica during hydraulic fracturing. Hydraulic fracturing involves high pressure injection of large volumes of water and sand, and smaller quantities of well treatment chemicals, into a gas or oil well to fracture shale or other rock formations, allowing more efficient recovery of hydrocarbons from a petroleum-bearing reservoir. Crystalline silica ("frac sand") is commonly used as a proppant to hold open cracks and fissures created by hydraulic pressure. Each stage of the process requires hundreds of thousands of pounds of quartz-containing sand; millions of pounds may be needed for all zones of a well. Mechanical handling of frac sand creates respirable crystalline silica dust, a potential exposure hazard for workers. Researchers at the National Institute for Occupational Safety and Health collected 111 personal breathing zone samples at 11 sites in five states to evaluate worker exposures to respirable crystalline silica during hydraulic fracturing. At each of the 11 sites, full-shift samples exceeded occupational health criteria (e.g., the Occupational Safety and Health Administration calculated permissible exposure limit, the NIOSH recommended exposure limit, or the ACGIH threshold limit value), in some cases, by 10 or more times the occupational health criteria. Based on these evaluations, an occupational health hazard was determined to exist for workplace exposures to crystalline silica. Seven points of dust generation were identified, including sand handling machinery and dust generated from the work site itself. Recommendations to control exposures include product substitution (when feasible), engineering controls or modifications to sand handling machinery, administrative controls, and use of personal protective equipment. To our knowledge, this represents the first systematic study of work crew exposures to crystalline silica during hydraulic fracturing. Companies that conduct hydraulic fracturing using silica sand should evaluate their operations to determine the potential for worker exposure to respirable crystalline silica and implement controls as necessary to protect workers.
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Affiliation(s)
- Eric J Esswein
- National Institute for Occupational Safety and Health, Western States Office, Denver, CO, USA.
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Nasrullah M, Mazurek JM, Wood JM, Bang KM, Kreiss K. Silicosis mortality with respiratory tuberculosis in the United States, 1968-2006. Am J Epidemiol 2011; 174:839-48. [PMID: 21828370 DOI: 10.1093/aje/kwr159] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The presence of tuberculosis (TB) in patients with silicosis increases mortality risk. To characterize silicosis-respiratory TB comortality in the United States, the authors used 1968-2006 National Center for Health Statistics multiple cause-of-death data for decedents aged ≥25 years. The authors calculated proportionate mortality ratios (PMRs) using available information on decedents' industries and occupations reported from 26 states from 1985 through 1999. Among 16,648 silicosis deaths, 2,278 (13.7%) had respiratory TB listed on the death certificate. Of silicosis-respiratory TB deaths, 1,666 decedents (73.1%) were aged ≥65 years, 2,255 (99.0%) were male, and 1,893 (83.1%) were white. Silicosis-respiratory TB deaths declined 99.5% during the study period (P < 0.001 for time-related trend), from 239.8 per year during 1968-1972 to 1.2 per year during 2002-2006, with no reported deaths in 2006. Silicosis-respiratory TB deaths reported from Pennsylvania (n = 525; 1.29 per million population), Ohio (n = 258; 0.81 per million), and West Virginia (n = 146; 2.35 per million) accounted for 40.8% of all such deaths in the United States. The highest PMR for silicosis-respiratory TB death was associated with the "miscellaneous nonmetallic mineral and stone products" industry (PMR = 73.7, 95% confidence interval: 33.8, 139.8). In the United States, 2006 marked the first year since 1968 with no silicosis-respiratory TB deaths. The substantial decline in silicosis-respiratory TB comortality probably reflects prevention and control measures for both diseases.
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Affiliation(s)
- Muazzam Nasrullah
- Division of Respiratory Disease Studies, National Institute for Occupational Safety and Health, Morgantown, West Virginia, USA.
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Barbosa MSDA, Carneiro APS, Maciel JGFS, Moronte EA, La Rocca PDF, Santos ARM. Silicose em trabalhadores de quartzito da região de São Thomé das Letras - Minas Gerais: dados iniciais indicam um grave problema de saúde pública. REVISTA BRASILEIRA DE SAÚDE OCUPACIONAL 2011. [DOI: 10.1590/s0303-76572011000100018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
INTRODUÇÃO: A exploração da pedra São Thomé, na região de São Thomé das Letras-MG, é antiga e estimam-se 2.000 trabalhadores envolvidos em sua extração e beneficiamento. No entanto, a silicose entre eles não era, até recentemente, registrada de forma consistente. OBJETIVO: Delinear o perfil ocupacional e radiológico de um grupo de trabalhadores de quartzito. Métodos: Série de 46 casos provenientes de um grupo de 185 extratores e beneficiadores cujos dados ocupacionais e radiografias de tórax foram analisados em ambulatório especializado. RESULTADOS: Todos os 185 trabalhadores eram do sexo masculino, com idade média de 41,3 anos e tempo de exposição mediano de 6,1 anos. As radiografias demonstraram imagens compatíveis com silicose em 46 (24,9%) deles. A ocorrência foi maior no setor de beneficiamento, onde também ocorreram os casos mais graves, incluindo três portadores de grandes opacidades e oito com formas aceleradas da doença. Os últimos, em geral mais jovens e com menor tempo de exposição, sugerem ter sido expostos a maiores concentrações de sílica. CONCLUSÃO: Apesar das limitações do estudo, a alta frequencia de silicose encontrada no grupo sugere serem precárias as medidas de prevenção da exposição à sílica, especialmente em épocas mais recentes. Isto pode ser reflexo da mecanização intensa ocorrida nos últimos anos, portanto, ações de vigilância e prevenção devem ser priorizadas no setor.
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Makol A, Reilly MJ, Rosenman KD. Prevalence of connective tissue disease in silicosis (1985-2006)-a report from the state of Michigan surveillance system for silicosis. Am J Ind Med 2011; 54:255-62. [PMID: 20957678 DOI: 10.1002/ajim.20917] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/13/2010] [Indexed: 11/06/2022]
Abstract
BACKGROUND The risk of developing clinical connective tissue disease (CTD) has been reported to be increased among individuals with silica exposure. METHODS We reviewed the medical records of individuals reported to the Michigan Silicosis Surveillance system from 1985 to 2006 to confirm the diagnosis of silicosis and determine the presence of CTDs. RESULTS From 1985 to 2006, 1,022 cases were confirmed to have silicosis. Medical records of 790 cases were available. Thirty-three individuals had rheumatoid arthritis (RA) [prevalence 4.2% (prevalence ratio (RR) ranged from 2.26, 95% CI: 1.57-3.25 to 6.96, 95% CI: 2.93-16.53) depending on the reference rate used], two had scleroderma [prevalence 0.3% (RR 28.3, 95% CI: 6.09-129.98)], one had systemic lupus erythematosus [prevalence 0.1% (RR 2.53, 95% CI: 0.30-21.64)], two had Sjogrens syndrome [prevalence 0.3% (RR 0.42, 95% CI: 0.09-2.08)], and six had anti-neutrophil cytoplasm antibody (ANCA) vasculitis [prevalence 0.8% (RR 25.3, 95% CI: 6.34-101.04)]. There was no difference between those with and without CTD with respect to age, race, industry type, history of tuberculosis, application for workers' compensation, or severity of fibrotic changes on chest X-ray. CONCLUSIONS A two- to eightfold risk for RA and systemic lupus erythematosus, with a greater than 24-fold risk for scleroderma and ANCA vasculitis was found in individuals with silicosis. The most common CTD among silicotics in the Michigan disease registry was RA. Though not classically included in the category of CTD, ANCA-associated vasculitis was found to have a much greater prevalence amongst silicosis patients than the general population.
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Affiliation(s)
- Ashima Makol
- Department of Medicine, Michigan State University, East Lansing, USA
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An engineering intervention resulting in improvement in lung function and change in urinary 8-hydroxydeoxyguanosine among foundry workers in Taiwan. Int Arch Occup Environ Health 2010; 84:175-83. [DOI: 10.1007/s00420-010-0580-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2009] [Accepted: 09/07/2010] [Indexed: 10/19/2022]
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Zhang M, Zheng YD, Du XY, Lu Y, Li WJ, Qi C, Wu ZL. Silicosis in automobile foundry workers: a 29-year cohort study. BIOMEDICAL AND ENVIRONMENTAL SCIENCES : BES 2010; 23:121-129. [PMID: 20514987 DOI: 10.1016/s0895-3988(10)60041-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
OBJECTIVES The purposes were to determine the relationship between silicosis among foundry workers and their cumulative exposure to silica dust, and to establish a regression model to predict the risk for developing silicosis by a given length of employment and air concentrations of silica at worksites. METHODS A 29-year cohort study was conducted, including all those employed for more than one year during January 1, 1980 to December 31, 1996 and all members of the cohort were followed-up to December 31, 2008. In total, 2009 workers of an automobile foundry in Shiyan, Hubei province were recruited in the study, 1300 at eight worksites including sand preparation, cast shakeout, and finishing, melting, moulding, core-making, overhead crane operation and pouring as exposed group, and the other 709 auxiliary workers at the same factory, such as electricians, inspectors, fitters, and so on, as control group. Person-years of observation were calculated by persons observed and years followed-up for each of them. Person-year incidence of silicosis and its relative risk (RR) or odds ratio (OR) and 95% confidence intervals (CI) among the workers were estimated, adjusted for relevant factors with logistic regression model using SPSS version 15.0 software. RESULTS Totally, 2009 workers were followed-up for 37 151 person-years and 48 cases of silicosis were found, with an overall incidence of 1.34 per thousand, 2.02 per thousand in exposed group, and 0.15 per thousand in control one. Risk of silicosis was significantly higher in the exposed group than that in the control one (RR = 13.13, 95% CI 3.18-54.13), higher in men than that in women (RR = 13.92, 95% CI 1.92-100.93). Risks of silicosis varied by job, highest in those exposed to cast shakeout and finishing (RR = 28.14, 95% CI 6.43-123.11), followed by those exposed to pouring (RR = 22.23, 95% CI 5.01-98.55) in the foundry. Average length of employment at onset of silicosis was 25.94 years, and silicosis incidence increased with length of employment. Average age at onset of silicosis was 47.83 years old. The risk of silicosis in workers with pulmonary tuberculosis was 2.57 folds as those without it (P < 0.01). Ten deaths were recorded in those with silicosis, with a case-fatality rate of 20.83 percent three of them died of lung cancer, three of liver cancer, two of ischemic heart disease, and two of other diseases as their immediate causes of death. Incidence of silicosis in foundry workers positively correlated with their cumulative silica exposure (OR = 3.00, 95% CI 2.34-3.83). Risks of silicosis increased by 4.38 folds with an increase of 1 mg/m3-year of cumulative silica exposure, and by 3.79 folds with smoking, respectively, adjusted for alcohol drinking and age. Based on a logistic regression model fitted, incidence of silicosis is expected to be 44.6 per thousand for those with daily exposure to silica of 4.18 mg/m3 in average for 30 years, and if incidence of silicosis is expected to be less than 1 per thousand, daily exposure to silica should be controlled below 0.2 mg/m3 for those with 20 years of employment, or below 0.1 mg/m3 for those with 30 or 40 years of silica exposure. CONCLUSIONS At present, foundry workers in China still face high risk of developing silicosis. For lowering occurrence of silicosis in exposed workers, it seems necessary that current occupational exposure limits for silica at worksites in China should be reexamined and silica dust control measures be strengthened.
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Affiliation(s)
- Min Zhang
- Department of Epidemiology, School of Basic Medicine, Peking Union Medical College, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, Beijing 100005, China
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Brown T. Silica exposure, smoking, silicosis and lung cancer--complex interactions. Occup Med (Lond) 2010; 59:89-95. [PMID: 19233828 DOI: 10.1093/occmed/kqn171] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Establishing a clear relationship between workplace exposures and cancer is often difficult. The latent period for cancer development can make it difficult to establish a definite cause-effect relationship. The picture is further complicated by variable job histories, concomitant exposure to other carcinogens and other factors such as genetic susceptibility and poor nutrition. The lack of accurate and detailed record keeping may potentially mask informative differences among group of workers. Removing or reducing exposures to probable and known carcinogens, however, can prevent workplace cancer. AIM This paper gives an overview of the literature reporting investigations of the relationship between exposure to silica and development of lung cancer with a focus on the controversy concerning the roles of silicosis and smoking in the development of cancer. METHOD A literature search was conducted to identify epidemiologic papers on silica, silicosis and lung cancer using electronic databases (MEDLINE, PubMed, Web of Science) from 1996 onwards and paper bibliographies. RESULTS If silicosis were the necessary step leading to lung cancer, enforcing the current silica standards would protect workers against lung cancer risk as well. Alternatively, a direct silica-lung cancer association that has been suggested implies that regulatory standards should be revised accordingly. CONCLUSION Further research is needed in order to understand the complex pattern of interactions leading to lung cancer among silica-exposed workers (and cancers and workplace exposures in general) and to understand whether and to what extent other workplace lung carcinogens, total respirable dust and total surface size and age of silica particles affect the carcinogenic potential of silica. In addition, the apparent paradox of a lower lung cancer risk in some workplaces with high-level silica exposure needs further investigation.
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Affiliation(s)
- Terry Brown
- Health & Safety Laboratory, Harpur Hill, Buxton, Derbyshire, UK.
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Andersson L, Bryngelsson IL, Ohlson CG, Nayström P, Lilja BG, Westberg H. Quartz and dust exposure in Swedish iron foundries. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2009; 6:9-18. [PMID: 18982534 DOI: 10.1080/15459620802523943] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Exposure to respirable quartz continues to be a major concern in the Swedish iron foundry industry. Recommendations for reducing the European occupational exposure limit (EU-OEL) to 0.05 mg/m3 and the corresponding ACGIH(R) threshold limit value (ACGIH-TLV) to 0.025 mg/m3 prompted this exposure survey. Occupational exposure to respirable dust and respirable quartz were determined in 11 Swedish iron foundries, representing different sizes of industrial operation and different manufacturing techniques. In total, 436 respirable dust and 435 respirable quartz exposure measurements associated with all job titles were carried out and are presented as time-weighted averages. Our sampling strategy enabled us to evaluate the use of respirators in certain jobs, thus determining actual exposure. In addition, measurements using real-time dust monitors were made for high exposure jobs. For respirable quartz, 23% of all the measurements exceeded the EU-OEL, and 56% exceeded the ACGIH-TLV. The overall geometric mean (GM) for the quartz levels was 0.028 mg/m3, ranging from 0.003 to 2.1 mg/m3. Fettler and furnace and ladle repair operatives were exposed to the highest levels of both respirable dust (GM = 0.69 and 1.2 mg/m3; range 0.076-31 and 0.25-9.3 mg/m3 and respirable quartz (GM = 0.041 and 0.052 mg/m3; range 0.004-2.1 and 0.0098-0.83 mg/m3. Fettlers often used respirators and their actual quartz exposure was lower (range 0.003-0.21 mg/m3, but in some cases it still exceeded the Swedish OEL (0.1 mg/m3. For furnace and ladle repair operatives, the actual quartz exposure did not exceed the OEL (range 0.003-0.08 mg/m3, but most respirators provided insufficient protection, i.e., factors less than 200. In summary, measurements in Swedish iron foundries revealed high exposures to respirable quartz, in particular for fettlers and furnace and ladle repair workers. The suggested EU-OEL and the ACGIH-TLV were exceeded in, respectively, 23% and 56% of all measurements regardless of the type of foundry. Further work on elimination techniques to reduce quartz concentrations, along with control of personal protection equipment, is essential.
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Affiliation(s)
- Lena Andersson
- Department of Occupational and Environmental Medicine, Orebro University Hospital, Orebro, Sweden.
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Scarselli A, Binazzi A, Marinaccio A. Occupational exposure to crystalline silica: estimating the number of workers potentially at high risk in Italy. Am J Ind Med 2008; 51:941-9. [PMID: 18651580 DOI: 10.1002/ajim.20619] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
BACKGROUND Occupational exposure to free silica is widespread in several economic sectors and is well known to cause silicosis. This study was designed to establish a database of enterprises and workers in industrial sectors involving silica exposure in Italy and to estimate the number of workers potentially at high risk of exposure. METHODS The industrial sectors at risk of silica exposure were identified by selecting the industrial sector that employed people who were compensated for silicosis in 2000-2004. The enterprises and the number of workers (blue-collar) potentially at risk of silica exposure were selected from the Italian database of workplaces. RESULTS The number of workers potentially at high risk of silica exposure, were 28,712. The most involved sectors were: construction, mining and quarrying, metal working, and manufacturing of non-metallic products. Among regions in Italy, some exposure-disease scenarios were cited in literature, particularly in Sardinia, Liguria, and Tuscany. CONCLUSIONS Establishing a database of industries related to silica dust exposure and identifying the number of workers potentially at high risk can be useful to reinforce preventive measures and to control exposure.
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Affiliation(s)
- Alberto Scarselli
- National Institute for Occupational Safety and Prevention (ISPESL), Occupational Medicine Department, Epidemiology Unit, Rome, Italy.
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Madl AK, Donovan EP, Gaffney SH, McKinley MA, Moody EC, Henshaw JL, Paustenbach DJ. State-of-the-science review of the occupational health hazards of crystalline silica in abrasive blasting operations and related requirements for respiratory protection. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART B, CRITICAL REVIEWS 2008; 11:548-608. [PMID: 18584454 DOI: 10.1080/10937400801909135] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Excessive exposures to airborne crystalline silica have been known for over 100 years to pose a serious health hazard. Work practices and regulatory standards advanced as the knowledge of the hazards of crystalline silica evolved. This article presents a comprehensive historical examination of the literature on exposure, health effects, and personal protective equipment related to silica and abrasive blasting operations over the last century. In the early 1900s, increased death rates and prevalence of pulmonary disease were observed in industries that involved dusty operations. Studies of these occupational cohorts served as the basis for the first occupational exposure limits in the 1930s. Early exposure studies in foundries revealed that abrasive blasting operations were particularly hazardous and provided the basis for many of the engineering control and respiratory protection requirements that are still in place today. Studies involving abrasive blasters over the years revealed that engineering controls were often not completely effective at reducing airborne silica concentrations to a safe level; consequently, respiratory protection has always been an important component of protecting workers. During the last 15-20 yr, quantitative exposure-response modeling, experimental animal studies, and in vitro methods were used to better understand the relationship between exposure to silica and disease in the workplace. In light of Occupational Safety and Health Administration efforts to reexamine the protectiveness of the current permissible exposure limit (PEL) for crystalline silica and its focus on protecting workers who are known to still be exposed to silica in the workplace (including abrasive blasters), this state-of-the-science review of one of the most hazardous operations involving crystalline silica should provide useful background to employers, researchers, and regulators interested in the historical evolution of the recognized occupational health hazards of crystalline silica and abrasive blasting operations and the related requirements for respiratory protection.
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Affiliation(s)
- Amy K Madl
- ChemRisk, Inc., San Francisco, California 94105, USA.
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Mazurek JM, Attfield MD. Silicosis mortality among young adults in the United States, 1968-2004. Am J Ind Med 2008; 51:568-78. [PMID: 18521821 DOI: 10.1002/ajim.20597] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
BACKGROUND To describe silicosis deaths in young (aged 15-44) adults in the U.S. during 1968-2004. METHODS We analyzed the National Center for Health Statistics multiple cause-of-death records. RESULTS Compared with silicosis decedents aged >or=45 years (n = 15,643), young decedents (n = 237) were more likely to have silicosis listed as the underlying cause of death (74.3% vs. 48.2%, P < 0.001), to be female (9.3% vs. 2.2%, P < 0.001) and black (37.1% vs. 11.7%, P < 0.001). Twenty-nine young silicosis decedents had industry and occupation information available. Occupations in construction and manufacturing industries were associated with significantly elevated proportionate mortality ratios for young silicosis deaths. CONCLUSIONS Silicosis deaths occur among young adults. Because these deaths are likely to reflect more intense and recent exposures, the follow-back investigations into the work sites where these individuals were exposed to silica should be conducted.
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Affiliation(s)
- Jacek M Mazurek
- Division of Respiratory Disease Studies, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia WV26 505, USA.
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Tse LA, Li ZM, Wong TW, Fu ZM, Yu ITS. High prevalence of accelerated silicosis among gold miners in Jiangxi, China. Am J Ind Med 2007; 50:876-80. [PMID: 17948247 DOI: 10.1002/ajim.20510] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Accelerated silicosis has become uncommon in developed countries, whereas serious health threat still exists in small-scale mining in developing countries. This study was to investigate the prevalence and risk factors of accelerated silicosis among Chinese gold miners. METHODS A cross-sectional medical examination was conducted among 574 Chinese gold miners. All participants were male rock-drillers. The concentrations of total dust and quartz content were obtained from the government documentations. Descriptive data analyses were performed. RESULTS The prevalence of accelerated silicosis was 29.1% (95% CI: 24.8-33.4%, 167 cases) after an average of 5.6 years of dust exposure, and a history of tuberculosis seemed to increase the risk. The concentration of respirable silica dust was estimated to be 89.5 mg/m(3) (ranged: 70.2-108.8) in the underground goldmine, far exceeding the permissible exposure limits. CONCLUSIONS This study illustrates a serious health threat to small-scale goldmine in China and indicates an urgent need for environmental control and disease prevention.
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Affiliation(s)
- Lap Ah Tse
- Department of Community & Family Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China
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Fanizza C, Ursini CL, Paba E, Ciervo A, Di Francesco A, Maiello R, De Simone P, Cavallo D. Cytotoxicity and DNA-damage in human lung epithelial cells exposed to respirable α-quartz. Toxicol In Vitro 2007; 21:586-94. [PMID: 17257809 DOI: 10.1016/j.tiv.2006.12.002] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2006] [Revised: 12/06/2006] [Accepted: 12/10/2006] [Indexed: 12/01/2022]
Abstract
Occupational exposure to respirable crystalline silica is associated with the development of silicosis, lung cancer and airways diseases. In order to assess cytotoxic effects and direct-oxidative DNA damage induced by short-term exposure to different doses of respirable alpha-quartz (NIST SRM1878a), we conducted a study using A549 cells. The cells were exposed to alpha-quartz at 25, 50, 100 microg/ml for 4 h and analysed by scanning electron microscope (SEM) and LDH release assay for cytotoxic effect evaluation. Cells were also exposed to 10, 25, 50, 100 microg/ml of alpha-quartz for 2 h and 4 h and analysed by Fpg comet test to evaluate direct and oxidative DNA damage. SEM observations of treated cells showed bleb development at lower doses and alterations of microvilli morphology at the highest dose. A slight LDH release was found only at 100 microg/ml. Fpg comet test showed a dose-related oxidative DNA damage in cells exposed for 2 h to quartz. Cells exposed for 4h at the same concentrations showed a dose-related direct DNA damage and the presence of oxidative DNA damage at lower doses. The bleb induction on cell surface evidenced by SEM at lower doses correlates with the presence of oxidative DNA damage at 4 h. The cell surface modifications observed by SEM at 100 microg/ml indicate that high doses of quartz induce more evident cytotoxic effects confirmed by LDH analysis and correlate with the genotoxicity showed by comet assay.
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Affiliation(s)
- Carla Fanizza
- Department of Occupational Hygiene, ISPESL, National Institute for Occupational Safety and Prevention, Via Fontana Candida 1, 00040 Monteporzio Catone, Rome, Italy.
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Yu ITS, Tse LA. Exploring the joint effects of silicosis and smoking on lung cancer risks. Int J Cancer 2007; 120:133-9. [PMID: 17036327 DOI: 10.1002/ijc.22133] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Cigarette smoking and silicosis are potential causes of lung cancer among workers exposed to silica dust, but their joint effects are unclear. We explored the possible interactions between silicosis and smoking on lung cancer risks by summarizing data from the published literature. The standardized mortality ratio or standardized incidence ratio reported in each published report was first adjusted using "smoking adjustment factors" to correct for the biased estimation of the expected numbers of lung cancer among smokers and nonsmokers when using general population rates in the indirect standardization process. The ratio of the effect of silicosis on lung cancer risk among smokers to that among nonsmoker was calculated and named the "relative silicosis effect (RSE)". The synergy index was estimated to assess the additive interaction. Metaanalyses were used to obtain the weighed means of the RSE and synergy index. Ten cohort studies were reviewed and combined to yield a weighed RSE of 0.29 (95% CI: 0.20, 0.42), indicating negative risk-ratio multiplication between smoking and silicosis on the lung cancer risk. The combined weighed synergy index was 1.00 (95% CI: 0.79, 1.26), suggesting no departure from additivity. Sensitivity analyses showed that both estimates were quite robust. The independent risk-ratio effect of silicosis on lung cancer in smokers was about 30% of that in nonsmokers, and the joint effects of smoking and silicosis on the risk of lung cancer did not deviate from additivity and hence did not support biological synergism/antagonism.
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Affiliation(s)
- Ignatius Tak-Sun Yu
- Department of Community and Family Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China.
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Mendonça EMC, Silva RCC, Bussacos MA, Algranti E. Respiratory impairment in Brazilian foundry workers exposed to sand. Am J Ind Med 2007; 50:83-91. [PMID: 17238133 DOI: 10.1002/ajim.20413] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE Foundries date back to the 16th century in Brazil and still constitute a strong economic activity today. Workers are at risk of respiratory diseases due to various exposures such as polycyclic aromatic hydrocarbons, pyrolysis degradation products, mineral dust, organic dust, resin, and isocyanates. We evaluate respiratory morbidity among workers in foundries using sand. METHODS Six foundries with sand molding operations were selected. Length of exposure in years was utilized as a surrogate for exposure. The medical evaluation consisted of a respiratory symptoms questionnaire, occupational history, spirometry, and chest X-rays. Additionally, workers exposed to resins and a control group underwent bronchial provocation tests. RESULTS A sample of 598 male workers with a mean age of 36.5 years (SD = 10.0) was analyzed. The mean length of exposure was 10.1 years (SD = 7.4). The overall prevalence of pneumoconiosis was 4.5%. Chronic bronchitis (CB) and X-ray profusion were significantly related to the quartiles of length of exposure (trend tests: P = 0.0055 and P < 0.001, respectively). There was a significant risk of having an abnormal FVC and FEV(1) with the presence of pneumoconiosis (OR = 4.63 CI 1.40-13-23, OR 3.34 CI 1.03-9.26, respectively). Workers exposed to resins compared with controls showed no differences in relation to spirometry, respiratory symptoms and bronchial reactivity. CONCLUSIONS There were significant associations between length of exposure CB and prevalence of profusion 1/0 or above. There was also a significant association for pneumoconiosis versus and abnormal FVC and FEV(1). Foundry workers currently exposed to resins did not show an excess of respiratory symptoms, abnormal spirometry or increased bronchial reactivity.
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Affiliation(s)
- E M C Mendonça
- Division of Medicine, FUNDACENTRO, Ministry of Labor and Employment, São Paulo, Brazil
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Carneiro APS, Barreto SM, Siqueira AL, Cavariani F, Forastiere F. Continued exposure to silica after diagnosis of silicosis in Brazilian gold miners. Am J Ind Med 2006; 49:811-8. [PMID: 16960888 DOI: 10.1002/ajim.20379] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
BACKGROUND There is a paucity of studies analyzing the effect of continued silica exposure after the onset of silicosis with regard to disease progression. The present study investigates differences in clinical and radiological presentation of silicosis among former workers with a diagnosis of silicosis, and compares workers who continued to be exposed to silica with those who stopped silica exposure after having received their diagnosis. METHODS A sample of 83 former gold miners with a median of 21 years from the first diagnoses of silicosis, had their clinical and occupational histories taken and underwent both chest radiography (International Labor Organization standards) and spirometry. Their silica exposure was assessed and an exposure index was created. The main outcome was the radiological severity of silicosis and tuberculosis (TB). The statistical analysis was done by multiple logistic regression. RESULTS Among the 83 miners, 44 had continued exposed to silica after being diagnosed with silicosis. Continuation of silica exposure was associated with advanced radiological images of silicosis (X-ray classification in category 3, OR = 6.42, 95% CI = 1.20-34.27), presence of coalescence and/or large opacities (OR = 3.85, CI = 1.07-13.93), and TB (OR = 4.61, 95% CI = 1.14-18.71). CONCLUSIONS Differential survival is unlikely to explain observed differences in silicosis progression. Results reinforce the recommendation that silica exposure should be halted at an early stage whenever X-ray is suggestive of the disease.
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Affiliation(s)
- Ana Paula Scalia Carneiro
- Regional Reference Centre on Workers' Health, Clinical Hospital, Federal University of Minas Gerais, Minas Gerais, Brazil.
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Carneiro APS, Barreto SM, Siqueira AL, La Rocca PF. Índice de exposição à sílica na atividade de mineração de ouro. Rev Saude Publica 2006; 40:83-91. [PMID: 16410987 DOI: 10.1590/s0034-89102006000100014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
OBJETIVO: Propor um índice que sintetize a exposição cumulativa à sílica, incluindo intensidade, duração e época da exposição e testá-lo em relação à presença e gravidade de silicose. MÉTODOS: Estudo transversal realizado com 140 ex-mineiros de ouro, residentes em duas localidades do Estado de Minas Gerais, examinados entre 11/1997 e 12/1999. Foram analisadas informações sobre história clínica e ocupacional, radiografia de tórax e espirometria. Casos borderline de silicose pela radiografia foram submetidos à tomografia computadorizada de alta resolução. O índice representa a soma dos escores extraídos da transformação logarítmica das taxas de concentração de sílica respirável nas diversas funções, minas e períodos trabalhados. Foram aplicados testes paramétricos para comparação das médias entre os grupos de interesse. RESULTADOS: O índice proposto apresentou-se discriminativo em relação ao desfecho principal (silicose) e aos desfechos secundários (enfisema e tuberculose) pulmonar no grupo total, incluindo os diversos estágios da doença, com valores p: 0,008, 0,016 e <0,001 respectivamente. Em relação às quatro categorias principais da silicose, o teste de Tukey evidenciou diferenças nas médias do índice entre as categorias 0 e 3 e 1 e 3. Porém, no subgrupo constituído pelos casos borderline, a discriminação entre os desfechos não foi satisfatória, tanto com diagnósticos obtidos pela radiografia quanto pela tomografia. CONCLUSÕES: O índice proposto representa um avanço na síntese da exposição ocupacional dos participantes, podendo ser usado para outras profissões. Entretanto, torna-se importante a incorporação de fatores clínicos e funcionais para entender a evolução da doença em expostos à sílica, especialmente nos casos duvidosos.
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Affiliation(s)
- Ana Paula Scalia Carneiro
- Ambulatório de Doenças Profissionais, Hospital das Clínicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
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Collins JF, Salmon AG, Brown JP, Marty MA, Alexeeff GV. Development of a chronic inhalation reference level for respirable crystalline silica. Regul Toxicol Pharmacol 2005; 43:292-300. [PMID: 16185799 DOI: 10.1016/j.yrtph.2005.08.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2005] [Indexed: 01/08/2023]
Abstract
Chronic inhalation exposure of workers to crystalline silica can result in silicosis. The general public can also be exposed to lower levels of crystalline silica from quarries, sand blasting, and entrained fines particles from surface soil. We have derived an inhalation chronic reference exposure level for silica, a level below which no adverse effects due to prolonged exposure would be expected in the general public. Incidence of silicosis and silica exposure data from a cohort of 2235 white South African gold miners yielded a reference level of 3 microg/m3) for respirable silica (particle size as defined occupationally) using a benchmark concentration approach. Data from cohorts of American gold miners, Chinese tin miners, diatomaceous earth workers, and black South African gold miners yielded similar results with a range of 3-10 microg/m3. Strengths of the chronic reference exposure level include the availability of several large long-term studies of inhalation in workers at varying exposure concentrations, adequate histopathological and radiologic analysis, adequate follow-up of exposed workers, a dose-response effect in several studies, observation of a No Observed Adverse Effect Level in the key study, and the power of the key study to detect a small effect. Uncertainties include the general underestimation of silicosis by radiography alone and the uncertainties in exposure estimation.
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Affiliation(s)
- James F Collins
- Air Toxicology and Epidemiology Branch, Office of Environmental Health Hazard Assessment, California Environmental Protection Agency, 1515 Clay Street, 16th Floor, Oakland, CA 94612, USA.
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Brown TP, Rushton L. Mortality in the UK industrial silica sand industry: 2. A retrospective cohort study. Occup Environ Med 2005; 62:446-52. [PMID: 15961620 PMCID: PMC1741056 DOI: 10.1136/oem.2004.017731] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AIMS To evaluate the mortality experience of a cohort of employees in the UK silica sand industry exposed to respirable crystalline silica (RCS). METHODS A retrospective cohort mortality study followed all workers to 2001 with at least one year's employment at one of seven UK silica sand producing quarries between 1950 and 1986. Each worker was assigned a job category and cumulative exposure to RCS was estimated using a job-exposure matrix. RESULTS A total of 764 deaths were identified in 2703 cohort members. The overall mortality rate for the cohort was lower than would be expected in the general population. Mortality from circulatory and respiratory disease was also less than expected, but death due to pneumoconiosis was slightly raised (two deaths). Mortality from all cancers was slightly decreased. Mortality was not raised in any job category. Cancer mortality was raised at one quarry due to a significant increase in lung (standardised mortality rate (SMR) 162.0, 95% CI 113.5 to 224.3) and bladder (SMR 366.5, 95% CI 167.6 to 695.7) cancers. Mortality from lung cancer and other causes did not show a trend with cumulative exposure to RCS. CONCLUSIONS This study did not show any consistent relation between RCS exposure (in the absence of other known carcinogens) and the development of lung cancer. This contrasts with a number of studies that have shown positive findings in similar and related industries.
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Affiliation(s)
- T P Brown
- Medical Research Council Institute for Environment and Health, 94 Regent Road, Leicester LE1 7DD, UK.
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Steenland K. One agent, many diseases: exposure-response data and comparative risks of different outcomes following silica exposure. Am J Ind Med 2005; 48:16-23. [PMID: 15940719 DOI: 10.1002/ajim.20181] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
BACKGROUND Evidence in recent years indicates that silica causes lung cancer, and probably renal disease, in addition to its well-known relationship to silicosis. There is also suggestive evidence that silica can cause arthritis and other auto-immune diseases. Silica has, therefore, joined a handful of other toxic exposures such as tobacco smoke, dioxin, and asbestos which cause multiple serious diseases. METHODS The available exposure-response data for silica and silicosis, lung cancer, and renal disease are reviewed. We compare the corresponding excess risks (or absolute risks in the case of silicosis) of death or disease incidence by age 75 for these three diseases, subsequent to a lifetime (45 years) of exposure to silica at current US standard (0.1 mg/m(3) respirable crystalline silica). RESULTS The absolute risk of silicosis, as defined by small opacities greater than or equal to ILO classification 1/1 on an X-ray, ranges from 47% to 77% in three cohort studies with adequate follow-up after employment. The absolute risk of death from silicosis is estimated at 1.9% (0.8%-2.9%), based on a pooled analysis of six cohort studies. The excess risk of lung cancer death, assuming US male background rates, is 1.7% (0.2%-3.6%), based on a pooled analysis of ten cohort studies. The excess risk of end-stage renal disease (assuming male background rates) is 5.1% (2.2%-7.3%), based on a single cohort. The excess risk of death from renal disease is estimated to be 1.8% (0.8%-9.7%), based on a pooled analysis of three cohorts. CONCLUSIONS Keeping in mind that the usual OSHA acceptable excess risk of serious disease or death for workers is 0.1%, it is clear that the current standard is far from sufficiently protective of workers' health. Perhaps surprisingly, kidney disease emerges as perhaps a higher risk than either mortality from silicosis or lung cancer, although the data are based on fewer studies.
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Affiliation(s)
- Kyle Steenland
- Rollins School of Public Health, Emory University, 1518 Clifton Road, Atlanta, GA 30322, USA.
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Abstract
OBJECTIVES We describe an emerging public health concern regarding silicosis in the fast-growing highway repair industry. METHODS We examined highway construction trends, silicosis surveillance case data, and environmental exposure data to evaluate the risk of silicosis among highway repair workers. We reviewed silicosis case data from the construction industry in 3 states that have silicosis registries, and we conducted environmental monitoring for silica at highway repair work sites. RESULTS Our findings indicate that a large population of highway workers is at risk of developing silicosis from exposure to crystalline silica. CONCLUSIONS Exposure control methods, medical screenings, protective health standards, and safety-related contract language are necessary for preventing future occupational disease problems among highway repair workers.
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Affiliation(s)
- David J Valiante
- New Jersey Department of Health and Senior Services, Occupational Health Surveillance Program, Trenton, NJ 08625, USA.
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Goodwin SS, Stanbury M, Wang ML, Silbergeld E, Parker JE. Previously undetected silicosis in New Jersey decedents. Am J Ind Med 2003; 44:304-11. [PMID: 12929151 DOI: 10.1002/ajim.10260] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND Despite a reported decline in mortality and hospitalizations associated with silicosis [U.S. Department of Health and Human Services, 1999], this decline may be artifactual, stemming in part from underdiagnosis by physicians. METHODS This study estimates, through radiological confirmation, the prevalence of unrecognized silicosis in a group of silica-exposed New Jersey decedents whose cause of death was chronic obstructive pulmonary disease (COPD), tuberculosis, or cor pulmonale. Two expert readers re-evaluated the chest X-rays of this group to determine the presence or absence of silicosis. The study population was considered to be presumptively exposed to silica dust by virtue of their usual industry of employment as listed on the death certificate. RESULTS Radiographic evidence of silicosis was found in 8.5% of this population, and evidence of asbestosis was found in another 10.7%, for a total of 19.2%. CONCLUSIONS The existence of previously unrecognized silicosis and asbestosis in 19.2% of this study group suggests that occupational lung disease is under-recognized and, hence, undercounted.
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Affiliation(s)
- Susan S Goodwin
- Department of Health Quantitative Sciences, Room 213, The Learning Center, New York Medical College, Valhalla, NY 10595, USA.
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Rosenman KD, Reilly MJ, Henneberger PK. Estimating the total number of newly-recognized silicosis cases in the United States. Am J Ind Med 2003; 44:141-7. [PMID: 12874846 DOI: 10.1002/ajim.10243] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND The US employer-based surveillance system for documenting occupational injuries and illnesses undercounts chronic diseases. We suggest a method to estimate the number of individuals who are newly-recognized with silicosis each year in the United States. METHODS Data from US death certificates, the Michigan state-based surveillance system, and capture-recapture analysis were used to calculate national estimates of silicosis. RESULTS From 1987 to 1996, 2,787 deaths occurred in the United States where silicosis was mentioned on the death certificates. During the same period, in Michigan 77% of death certificates with a mention of silicosis were confirmed as silicosis-related deaths and the ratio of the number of living to deceased confirmed silicosis cases was 6.44. The proportion of confirmed silicosis deaths, the ratio of the living to deceased silicosis cases and capture-recapture analysis from the Michigan surveillance system, were used to estimate that there were 3,600-7,300 cases per year of silicosis in the United States from 1987 to 1996. CONCLUSIONS Our estimate of the annual number of newly-recognized silicosis cases is significantly larger than the estimate from the employer-based reporting system used for counting occupational disease in the United States. This employer-based surveillance system is inadequate for determining the frequency of occupational disease. Our analysis which combines a readily-available and relatively inexpensive national administrative database (i.e., death certificates) with a more costly state-based active surveillance system is a cost-effective model that could be used to provide better estimates of a number of different occupational diseases. Accurate estimates of occupational illnesses are essential to both determine temporal trends and evaluate efforts to prevent silicosis.
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Affiliation(s)
- Kenneth D Rosenman
- Michigan State University, 117 West Fee, East Lansing, Michigan 48824-1315, USA.
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48
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Abstract
Coal mine and silica dust cause significant respiratory disease in spite of modern dust control regulations. Susceptible individuals in exposed populations may develop fibrosing lung disease, obstructive airways disease, including chronic bronchitis and emphysema, or lung cancer. A careful occupational history that elicits exposure to respiratory hazards is the cornerstone of an accurate diagnosis. Treatment involves removal from exposure, supportive care, pulmonary rehabilitation, and when disabling disease is present, assistance obtaining compensation.
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Affiliation(s)
- Robert Cohen
- Rush University Medical College, Division of Occupational Medicine and Pulmonary Medicine/Critical Care, Cook County Hospital, Chicago, IL, USA.
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49
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't Mannetje A, Steenland K, Attfield M, Boffetta P, Checkoway H, DeKlerk N, Koskela RS. Exposure-response analysis and risk assessment for silica and silicosis mortality in a pooled analysis of six cohorts. Occup Environ Med 2002; 59:723-8. [PMID: 12409529 PMCID: PMC1740236 DOI: 10.1136/oem.59.11.723] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AIMS To study the relation between exposure to crystalline silica and silicosis mortality. Although mortality is an important endpoint for regulators, there have been no exposure-response studies for silicosis mortality, because of the relative rareness of silicosis as an underlying cause of death, and the limited availability of quantitative exposure estimates. METHODS Data from six occupational cohorts were pooled with good retrospective exposure data in which 170 deaths from silicosis were reported. Standard life table analyses, nested case-control analyses, and risk assessment were performed. RESULTS The rate of silicosis mortality in the combined data was 28/100 000 py, increasing in nearly monotonic fashion from 4.7/100 000 for exposure of 0-0.99 mg/m(3)-years to 233/100 000 for exposure of >28.1 mg/m(3)-years. The estimated risk of death up to age 65 from silicosis after 45 years of exposure at 0.1 mg/m(3) silica (the current standard in many countries) was 13 per 1000, while the estimated risk at an exposure of 0.05 mg/m(3) was 6 per 1000. Both of these risks are above the risk of 1 per 1000 typically deemed acceptable by the US OSHA. CONCLUSION The findings from this pooled analysis add further support to the need to control silica exposure and to lower the occupational standards. Our estimates of lifetime silicosis mortality risk are probably underestimates as, in addition to exposure misclassification, our study might have suffered from outcome misclassification in that silicosis deaths might have been coded to other related causes, such as tuberculosis or chronic obstructive pulmonary disease.
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Affiliation(s)
- A 't Mannetje
- International Agency for Research on Cancer (IARC), Unit of Environmental Cancer Epidemiology, Lyon, France.
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50
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CARNEIRO ANAPAULASCALIA, CAMPOS LUCIANODEOLIVEIRA, GOMES MARCELOFONSECACOUTINHOFERNANDES, ASSUNÇÃO ADAÁVILA. Perfil de 300 trabalhadores expostos à sílica atendidos ambulatorialmente em Belo Horizonte. ACTA ACUST UNITED AC 2002. [DOI: 10.1590/s0102-35862002000600006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Introdução: A silicose é a pneumoconiose de maior prevalência no Brasil, sendo a maioria dos casos proveniente do Estado de Minas Gerais. Apesar de ser uma doença evitável, continuam ocorrendo epidemias localizadas. Objetivo: Descrever o perfil dos trabalhadores atendidos no Ambulatório de Doenças Profissionais do Hospital das Clínicas da Universidade Federal de Minas Gerais. Material e métodos: Foram estudados 300 prontuários de trabalhadores expostos à sílica em diversas atividades profissionais, atendidos no período de 1989 a 2000, sendo analisados dados clínico-ocupacionais, espirométricos e radiológicos. Realizaram-se análises univariadas, utilizando o teste do qui-quadrado e teste t. Resultados e conclusão: A média de idade dos pacientes expostos foi de 51 anos, com tempo médio de exposição de 15,6 anos. Diagnosticaram-se radiologicamente 126 (42%) casos de silicose, constatando-se que, quanto mais avançada a categoria radiológica da doença, piores foram os resultados à espirometria e mais freqüentes as associações com tuberculose e com limitação crônica ao fluxo aéreo. O mercado de trabalho formal representou o principal vínculo empregatício, sendo a mineração a principal atividade exercida, responsável pela exposição de 197 indivíduos (66%). Os trabalhadores do mercado informal foram aqueles que apresentaram achados radiológicos indicativos de formas mais avançadas da doença, sugerindo piores condições de exposição à sílica, neste grupo de trabalhadores.
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Affiliation(s)
| | | | | | - ADA ÁVILA ASSUNÇÃO
- Universidade Federal de Minas Gerais; Laboratório de Ergonomia Fisiológica e Cognitiva de Paris
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