Effectiveness of dust control methods for crystalline silica and respirable suspended particulate matter exposure during manual concrete surface grinding

Details

• Personal Author:
  Akbar-Khanzadeh F ; Akbar-Khanzadeh M ; Ames AL ; Bisesi MS ; Khuder S ; Milz SA ; Susi, Pam ; Wagner CD
• Description:
  Concrete grinding exposes workers to unacceptable levels of crystalline silica dust, known to cause diseases such as silicosis and possibly lung cancer. This study examined the influence of major factors of exposure and effectiveness of existing dust control methods by simulating field concrete grinding in an enclosed workplace laboratory. Air was monitored during 201 concrete grinding sessions while using a variety of grinders, accessories, and existing dust control methods, including general ventilation (GV), local exhaust ventilation (LEV), and wet grinding. Task-specific geometric mean (GM) of respirable crystalline silica dust concentrations (mg/m3 for LEV:HEPA-, LEV:Shop-vac-, wet-, and uncontrolled-grinding, while GV was off/on, were 0.17/0.09, 0.57/0.13, 1.11/0.44, and 23.1/6.80, respectively. Silica dust concentrations (mg/m3 using 100-125 mm (4-5 inch) and 180 mm (7 inch) grinding cups were 0.53/0.22 and 2.43/0.56, respectively. GM concentrations of silica dust were significantly lower for (1) GV on (66.0%) vs. off, and (2) LEV:HEPA- (99.0%), LEV:Shop-vac- (98.1%) or wet- (94.4%) vs. uncontrolled-grinding. Task-specific GM of respirable suspended particulate matter (RSP) concentrations (mg/m3 for LEV:HEPA-, LEV:Shop-vac-, wet-, and uncontrolled grinding, while GV was off/on, were 1.58/0.63, 7.20/1.15, 9.52/4.13, and 152/47.8, respectively. GM concentrations of RSP using 100-125 mm and 180 mm grinding cups were 4.78/1.62 and 22.2/5.06, respectively. GM concentrations of RSP were significantly lower for (1) GV on (70.2%) vs. off, and (2) LEV:HEPA- (98.9%), LEV:Shop-vac- (96.9%) or wet- (92.6%) vs. uncontrolled grinding. Silica dust and RSP were not significantly affected by (1) orientation of grinding surfaces (vertical vs. inclined); (2) water flow rates for wet grinding; (3) length of task-specific sampling time; or, (4) among cup sizes of 100, 115 or 125 mm. No combination of factors or control methods reduced an 8-hr exposure level to below the recommended criterion of 0.025 mg/m3 for crystalline silica, requiring further refinement in engineering controls, administrative controls, or the use of respirators. [Description provided by NIOSH]
• Subjects:
  Dust Engineering Occupational Health Personal Protective Equipment Quartz Respiratory Protective Devices Respiratory System Safety Silicon Dioxide
• Keywords:
  Author Keywords: Concrete Grinding Construction Control-methods Control-technology Crystalline Silica Dust Dust-control Dust-control-equipment Dust-exposure Dust-particles Dust Control Methods Dusts Engineering-controls Quartz-dust Respirable-dust Respirators Respiratory-equipment Respiratory-protective-equipment Silica-dusts

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• ISSN:
  1545-9624
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  Maryland ; Ohio ; OSHA Region 3 ; OSHA Region 5
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  7
• Issue:
  12
• NIOSHTIC Number:
  nn:20038145
• Citation:
  J Occup Environ Hyg 2010 Dec; 7(12):700-711
• Contact Point Address:
  Farhang Akbar-Khanzadeh, University of Toledo Health Science Campus, College of Medicine, MS 1027, Department of Public Health & Preventive Medicine, 3000 Arlington Ave., Toledo, OH 43614
• Email:
  Farhang.Akbar@UToledo.edu
• CAS Registry Number:
  Quartz (SiO2) (CAS RN 14808-60-7)
• Federal Fiscal Year:
  2011
• Performing Organization:
  University of Toledo
• Peer Reviewed:
  True
• Start Date:
  20070901
• Source Full Name:
  Journal of Occupational and Environmental Hygiene
• End Date:
  20090831
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:f4fbd014312fecb1d949088f6fcd042462659e5f6565711c0d7e0f26bca895b59ce056f4a04343146277cf98d2c1075601795956c8961ce5c8fa6852e91aeb94
• Download URL:
  https://stacks.cdc.gov/view/cdc/191943/cdc_191943_DS1.pdf
• File Type:
  [PDF - 436.74 KB ]