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Gorman Ng M, Li AM, Lavoué J, Davies HW. Determinants of respirable crystalline silica exposure in construction in western Canada. Ann Work Expo Health 2023; 67:847-857. [PMID: 37348109 DOI: 10.1093/annweh/wxad036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 06/05/2023] [Indexed: 06/24/2023] Open
Abstract
Task-based respirable crystalline silica (RCS) exposure monitoring data was collected from construction work sites across 3 Canadian provinces: Alberta, British Columbia (BC), and Manitoba. In total 373 RCS samples were obtained from 70 worksites across 44 companies. Sampling was conducted between May 2015 and August 2020. The overall geometric mean (GM) RCS exposure was 0.045 mg/m3 (geometric standard deviation, GSD = 6.8). Alberta had the highest average exposure and the highest variability with GM of 0.060 mg/m3 (GSD = 9.3), the GM in BC was 0.044 (GSD = 4.3), and in Manitoba the GM was 0.033 (GSD = 7.0). A multivariable model was built using forward stepwise linear regression modeling. Province, task type, work environment (indoor vs. outdoor), construction material, sampling duration, and engineering control use were all statistically significant predictors of exposure level in partial F-tests (P < 0.05). Overall, the model explained 42% of the RCS concentration variability. Task type contributed most to the model's explanatory power. The task type with highest average exposure levels was demolition (GM 0.30 mg/m3, GSD 0.49). Breaking (GM 0.16 mg/m3, GSD 8.4) and grinding (GM 0.081 m/m3, GSD 7.4) also had high-exposure levels. Working outdoors was associated with exposure levels 39% lower than indoors. Exposure control measures such as local exhaust ventilation and wetting were also associated with lower exposure levels. Among construction materials, Cement, sand, and stone were associated with higher RCS exposure levels relative to the reference material, concrete. The results of this study indicate that workers in western Canada remain exposed to RCS at levels that exceed the health-based American Congress for Governmental Industrial Hygienists Threshold Limit Value of 0.025 mg/m3. Although there were some differences in exposure levels between the provinces, the determinants of exposure were similar in all 3. The overall GM RCS exposure was 0.045 mg/m3 (geometric standard deviation, GSD = 6.8). Alberta had the highest average exposure and the highest variability with GM of 0.060 mg/m3 (GSD = 9.3), the GM in BC was 0.044 (GSD = 4.3), and in Manitoba the GM was 0.033 (GSD = 7.0).
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Affiliation(s)
- Melanie Gorman Ng
- School of Population and Public Health, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
- BC Construction Safety Alliance, New Westminster, British Columbia V3M 5Y4, Canada
| | - Avril Mu Li
- BC Construction Safety Alliance, New Westminster, British Columbia V3M 5Y4, Canada
| | - Jérôme Lavoué
- Department of Environmental and Occupational Health, Université de Montréal, School of Public Health, Montréal, Quebec H3N 1X9, Canada
| | - Hugh W Davies
- School of Population and Public Health, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
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Couture A, Charuvil Elizabeth RM, Lefsrud L, Sattari F. Evaluation of workplace exposure to respirable crystalline silica in road construction industries in Alberta. Toxicol Ind Health 2023:7482337231176602. [PMID: 37258490 DOI: 10.1177/07482337231176602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Occupational exposure to respirable crystalline silica (RCS) is common for several occupations in construction, not only because of its presence in many handling materials but also in processes such as grinding and sawing. This study investigated workplace exposure to RCS as quartz in industries and occupations within road construction in Alberta through the RCS monitoring database provided by the Alberta Roadbuilders and Heavy Construction Association (ARHCA) between 2007 and 2016. Descriptive statistics were calculated for exposure-related variables, and mixed model analysis was performed to determine factors affecting the exposure levels. Results showed that the highest exposed workers were in the sand and gravel industry (GM = 45 μg/m3). For worker occupations, geometric means ranged from 78 μg/m3 for crusher operators to 10 μg/m3 for concrete truck operators. The maximum exposure severity was 33.3 times the occupational exposure limit (OEL) for the sand and gravel and 31 times the OEL for tower operators. The results also showed the effect of seasonal variability on RCS exposure levels. The heterogeneous exposure results indicated significant room for improvement and that controls should focus more on the activity performed than the occupation to lower exposure to RCS levels in industries.
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Affiliation(s)
- Ariel Couture
- Department of Mechanical Engineering, University of Alberta, Edmonton, AB, Canada
| | - Rose Marie Charuvil Elizabeth
- Department of Chemical and Materials Engineering, School of Engineering Safety and Risk Management, University of Alberta, Edmonton, AB, Canada
| | - Lianne Lefsrud
- Department of Chemical and Materials Engineering, School of Engineering Safety and Risk Management, University of Alberta, Edmonton, AB, Canada
| | - Fereshteh Sattari
- Department of Chemical and Materials Engineering, School of Engineering Safety and Risk Management, University of Alberta, Edmonton, AB, Canada
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Anlimah F, Gopaldasani V, MacPhail C, Davies B. A systematic review of the effectiveness of dust control measures adopted to reduce workplace exposure. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:54407-54428. [PMID: 36964805 PMCID: PMC10121514 DOI: 10.1007/s11356-023-26321-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 03/03/2023] [Indexed: 06/18/2023]
Abstract
The recent increase in silicosis cases in several countries casts doubt on dust control practices and their effectiveness in preventing respirable crystalline silica (RCS) exposure. Apart from silicosis, RCS may lead to other illnesses, health-related quality of life losses for workers and their families, and economic losses for companies. Thus, this systematic literature review examined the effectiveness of interventions employed to prevent exposure to RCS and increase the use of dust control measures. The review used keywords related to dust control interventions to search seven databases. Search results were screened and extracted for synthesis. The narrative synthesis showed the extent of research investment in China. In several designs and combinations, the interventions utilized water, surfactant, foam, and air currents to reduce dust exposure. These interventions offer varying degrees of dust control effectiveness against RCS and respirable dust. Although evidence indicates that interventions significantly decrease dust concentration levels, the control measures in place may not effectively prevent workplace overexposure to RCS. The review found that education and training interventions are employed to improve dust controls and respiratory protective equipment (RPE) use. Also, marketing strategies promote the use of RPE. These interventions can increase the frequency of use of RPE and the adoption of best practice dust control measures. Interventions increase knowledge, awareness, and attitudes about RPE usage and generate positive perceptions while reducing misconceptions. However, the benefits obtained from an intervention may diminish after its implementation, indicating that the interventions may not continually motivate workers to adopt control measures or use RPE.
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Affiliation(s)
- Frederick Anlimah
- Faculty of the Arts, Social Sciences and Humanities, School of Health and Society, Centre for Occupational Public and Environmental Research in Safety and Health (COPERSH), University of Wollongong, Building 29, Wollongong, NSW 2522 Australia
| | - Vinod Gopaldasani
- Faculty of the Arts, Social Sciences and Humanities, School of Health and Society, Centre for Occupational Public and Environmental Research in Safety and Health (COPERSH), University of Wollongong, Building 29, Room 124, Wollongong, NSW 2522 Australia
| | - Catherine MacPhail
- Faculty of the Arts, Social Sciences and Humanities, School of Health and Society, University of Wollongong, Building 29, Room 242, Wollongong, NSW 2522 Australia
| | - Brian Davies
- Faculty of the Arts, Social Sciences and Humanities, School of Health and Society, Centre for Occupational Public and Environmental Research in Safety and Health (COPERSH), University of Wollongong, Building 29, Room 116, Wollongong, NSW 2522 Australia
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Sahihazar ZM, Ghahramani A, Galvani S, Hajaghazadeh M. Probabilistic health risk assessment of occupational exposure to crystalline silica in an iron foundry in Urmia, Iran. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:82014-82029. [PMID: 35748987 DOI: 10.1007/s11356-022-21487-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 06/11/2022] [Indexed: 06/15/2023]
Abstract
This study aimed to quantify the exposure of foundry workers to crystalline silica and associated cancer and non-cancer health risks using a probabilistic approach. Breathing zone air samples were collected according to the NIOSH 7602 method and analyzed using Fourier transform infrared spectroscopy. The health risks posed by crystalline silica were then assessed using the EPA-developed inhalation risk assessment model and Monte Carlo simulation. The sensitivity analysis was also conducted to determine the contribution of input parameters to the health risks. The mean concentration of crystalline silica in six foundry stations ranged from 0.029 to 0.064 mg m-3, exceeding the occupational exposure limits. The average values of cancer risks were greater than the USEPA level, i.e., 1E - 6 in all workstations of the foundry. Workers in sand preparation and molding stations suffered the greatest cancer risks, with the mean value of 2.35E - 5 and 2.10E - 5, respectively. Non-cancer hazard quotient exceeded 1 in all foundry stations ranging from 1.56 (in melting and pouring) to 3.37 (in sand preparation). The 95% upper-bound values of the health risks decreased by 77.52% and 56.77%, assuming the use of engineering controls and wearing respirators by workers, respectively. Sensitivity analyses indicate that concentration was the most sensitive factor contributing to the carcinogenic (46.13%) and non-carcinogenic (67.08%) risks. These findings can aid managers in gaining a better understanding of the silica risks faced by foundry workers and the role of engineering controls and respirators in protecting workers' health.
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Affiliation(s)
- Zahra Moutab Sahihazar
- Department of Occupational Health, School of Public Health, Urmia University of Medical Sciences, Urmia, Iran
| | - Abolfazl Ghahramani
- Department of Occupational Health, School of Public Health, Urmia University of Medical Sciences, Urmia, Iran
| | - Sadjad Galvani
- Department of Power Engineering, Faculty of Electrical, and Computer Engineering, Urmia University, Urmia, Iran
| | - Mohammad Hajaghazadeh
- Department of Occupational Health, School of Public Health, Urmia University of Medical Sciences, Urmia, Iran.
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Ziembicki S, Kirkham TL, Demers PA, Peters CE, Gorman Ng M, Davies HW, Tenkate T, Kalenge S, Blagrove-Hall N, Jardine KJ, Arrandale VH. Diesel Engine Exhaust Exposure in the Ontario Civil Infrastructure Construction Industry. Ann Work Expo Health 2021; 66:150-162. [PMID: 34585719 DOI: 10.1093/annweh/wxab068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 07/26/2021] [Accepted: 08/06/2021] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES Diesel engine exhaust (DEE) is a known lung carcinogen and a common occupational exposure in Canada. The use of diesel-powered equipment in the construction industry is particularly widespread, but little is known about DEE exposures in this work setting. The objective of this study was to determine exposure levels and identify and characterize key determinants of DEE exposure at construction sites in Ontario. METHODS Elemental carbon (EC, a surrogate of DEE exposure) measurements were collected at seven civil infrastructure construction worksites and one trades training facility in Ontario using NIOSH method 5040. Full-shift personal air samples were collected using a constant-flow pump and SKC aluminium cyclone with quartz fibre filters in a 37-mm cassette. Exposures were compared with published health-based limits, including the Dutch Expert Committee on Occupational Safety (DECOS) limit (1.03 µg m-3 respirable EC) and the Finnish Institute of Occupational Health (FIOH) recommendation (5 µg m-3 respirable EC). Mixed-effects linear regression was used to identify determinants of EC exposure. RESULTS In total, 149 EC samples were collected, ranging from <0.25 to 52.58 µg m-3 with a geometric mean (GM) of 3.71 µg m-3 [geometric standard deviation (GSD) = 3.32]. Overall, 41.6% of samples exceeded the FIOH limit, mostly within underground worksites (93.5%), and 90.6% exceeded the DECOS limit. Underground workers (GM = 13.20 µg m-3, GSD = 1.83) had exposures approximately four times higher than below grade workers (GM = 3.56 µg m-3, GSD = 1.94) and nine times higher than above ground workers (GM = 1.49 µg m-3, GSD = 1.75). Training facility exposures were similar to above ground workers (GM = 1.86 µg m-3, GSD = 4.12); however, exposures were highly variable. Work setting and enclosed cabins were identified as the key determinants of exposure in the final model (adjusted R2 = 0.72, P < 0.001). The highest DEE exposures were observed in underground workplaces and when using unenclosed cabins. CONCLUSIONS This study provides data on current DEE exposure in Canadian construction workers. Most exposures were above recommended health-based limits, albeit in other jurisdictions, signifying a need to further reduce DEE levels in construction. These results can inform a hazard reduction strategy including targeted intervention/control measures to reduce DEE exposure and the burden of occupational lung cancer.
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Affiliation(s)
- Stephanie Ziembicki
- Occupational Cancer Research Centre, Ontario Health, Toronto, ON, Canada.,Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada
| | - Tracy L Kirkham
- Occupational Cancer Research Centre, Ontario Health, Toronto, ON, Canada.,Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada
| | - Paul A Demers
- Occupational Cancer Research Centre, Ontario Health, Toronto, ON, Canada.,Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada.,School of Population and Public Health, University of British Columbia, Vancouver, BC, Canada
| | - Cheryl E Peters
- Department of Cancer Epidemiology and Prevention Research, Alberta Health Services, Holy Cross Centre, AB, Canada.,Department of Community Health Sciences, Cumming School of Medicine, University of Calgary, 3280 Hospital Drive NW, Calgary, AB, Canada.,Department of Oncology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,CAREX Canada, Faculty of Health Sciences, Simon Fraser University, Vancouver, BC, Canada
| | - Melanie Gorman Ng
- School of Population and Public Health, University of British Columbia, Vancouver, BC, Canada.,BC Construction Safety Alliance, New Westminster, BC, Canada
| | - Hugh W Davies
- School of Population and Public Health, University of British Columbia, Vancouver, BC, Canada
| | - Thomas Tenkate
- School of Occupational and Public Health, Ryerson University, Toronto, ON, Canada
| | - Sheila Kalenge
- Occupational Cancer Research Centre, Ontario Health, Toronto, ON, Canada
| | | | | | - Victoria H Arrandale
- Occupational Cancer Research Centre, Ontario Health, Toronto, ON, Canada.,Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada
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Blagrove-Hall N, Berriault C, Jardine KJ, Demers PA, Arrandale VH. Estimating Historical Exposure to Respirable Crystalline Silica in the Mining Industry in Ontario, Canada Using a Newly Developed Exposure Database. Ann Work Expo Health 2021; 65:1040-1049. [PMID: 34170289 DOI: 10.1093/annweh/wxab033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 03/31/2021] [Accepted: 04/21/2021] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVES To use the recently developed Ontario Mining Exposure Database (OMED) to describe historical silica exposure in the Ontario metal mining industry and identify predictors of historical silica exposure. METHODS Personal respirable crystalline silica (RCS) data for metal mines were extracted from OMED and included both individual and summary measures, where multiple exposure measurements (n > 1) were aggregated and entered as a single exposure value (n = 1). Data were stratified by sample location (underground/surface) for analysis. Monte Carlo simulation was used to simulate individual measures from the summary measures. A fixed effects multiple linear regression model was used to assess the effects of commodity (ore mined), sample year, source of exposure data, and occupational group on RCS concentration. Parameter estimates (β), standard errors, and 95% upper and lower confidence intervals were reported. RESULTS The OMED contained 12 995 silica measurements. After limiting to RCS measurements in metal mines, and measures with sufficient information for analysis, 2883 RCS measurements collected from 1974 to 1991 remained, including 2816 individual and 67 summary measurements. In total, 321 individual RCS measurements were simulated from the 67 summary measures. The analysis database contained 2771 (12% simulated) underground measurements and 366 surface measurements (0% simulated). In the underground group, an overall geometric mean (GM) of 0.05 [geometric standard deviation (GSD) 3.09] mg m-3 was estimated with a 6% annual decrease over time. In this group, the commodity with the highest average RCS level was zinc mines (GM = 0.07 mg m-3) and the lowest was iron mines (GM = 0.01 mg m-3). In the surface group, an overall GM of 0.05 (GSD 3.70) mg m-3 was estimated with an 8% decreased over time. In this group, the commodity with the highest average RCS level was gold mines (GM = 0.07 mg m-3) and the lowest was zinc mines (GM = 0.03 mg m-3). In both groups, company collected data had lower estimated RCS compared with regulator collected data. CONCLUSIONS Historical RCS levels decreased over time. Mean measurements exceeded the American Conference of Governmental Industrial Hygienists current health-based threshold limit value (0.025 mg m-3). The main predictors of exposure were commodity, source of exposure data, and sample year. However, low R2 and high GSD values suggest additional predictors of RCS exposures in Ontario's metal mines exist that were unavailable in OMED.
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Affiliation(s)
| | - Colin Berriault
- Occupational Cancer Research Centre, Ontario Health, Toronto, ON, Canada
| | | | - Paul A Demers
- Occupational Cancer Research Centre, Ontario Health, Toronto, ON, Canada
- Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada
| | - Victoria H Arrandale
- Occupational Cancer Research Centre, Ontario Health, Toronto, ON, Canada
- Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada
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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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