Characterization of Occupational Exposures to Respirable Silica and Dust in Demolition, Crushing, and Chipping Activities

Details

• Personal Author:
  Bello A ; Mugford, Christopher ; Murray A ; Shepherd S ; Woskie SR
• Description:
  Objectives: Exposures to respirable crystalline silica (RCS) and respirable dust (RD) were investigated during demolition, crushing, and chipping at several Massachusetts construction sites. Methods: Personal breathing zone samples (n = 51) were collected on operating engineers working at demolition and crushing sites, laborers performing miscellaneous tasks at demolition sites, crushing machine tenders at crushing sites, and chipping workers at substructure bridge repair sites. Area samples (n = 33) were collected at the perimeter of demolition and crushing sites to assess potential bystanders' exposures. Exposures 'with' and 'without' the use of dust suppression methods were compared when possible. RD samples were analyzed for crystalline silica content with Fourier Transform Infrared Spectrophotometry (FT-IR) according to the National Institute for Occupational Safety and Health (NIOSH) Method 7602. Statistical analyses of the exposure data were performed in SAS version 9.4. Results: Chipping workers had the highest exposure levels [the geometric mean (GM) time-weighted average (TWA) for RCS was 527 microg/m3 and the GM for RD was 4750 microg/m3]. The next highest exposures were among crushing machine tenders (RCS GM of 93.3 microg/m3 and RD GM of 737.6 microg/m3), while laborers and operating engineers had the lowest exposures (RCS GM of 17.0 and 6.2 microg/m3, respectively). Personal 8-h TWA RCS exposures were higher than the new OSHA permissible exposure limit (PEL) of 50 microg/m3 for 80% of samples collected on chipping workers (n = 31) and 50% of samples collected on crushing machine tenders (n = 8). Operating engineers (n = 9) and laborers (n = 3) had RCS exposures lower than OSHA PEL. The highest concentrations measured would have exceeded the PEL within 15 min chipping and within 2 h of crushing with no further exposure. Chipping workers' RCS exposures were higher than OSHA PEL even when they were adjusted to account for the assigned protection factor of the half-face N95 cartridge respirators used during chipping. Exposures of crushing tenders were reduced to levels under the OSHA PEL when a water spraying system in crushing machines was utilized, but not when a water cannon machine was used. Area samples at demolition and crushing sites indicate overall lower exposures than the PEL, however, bystander workers at crushing sites could be exposed to higher levels compared to demolition sites. Real-time dust monitoring during demolition indicate very high short-term peak exposures. Conclusions: Controlling or reducing crystalline silica exposures to levels under the new OSHA PEL of 50 microg/m3 remains challenging for chipping workers and crushing machine tenders. Even with the use of dust suppression controls, respiratory protection may be required for various tasks. [Description provided by NIOSH]
• Subjects:
  Construction Industry Dust Environmental Exposure Occupational Health Safety Silicon Dioxide
• Keywords:
  Analytical Method Analytical Methods Author Keywords: Chipping Breathing Zone Construction Construction Equipment Construction Industry Construction Workers Crushing Crystalline Silica Demolition Demolition Industry Dust Exposure Exposure Assessment Exposure Levels Exposure Limits Heavy Equipment Occupational Safety And Health Administration OSHA PELs Permissible Exposure Limits Respirable Crystalline Silica Respirable Dust Sampling Short Term Exposure Silica Dusts Statistical Analysis Time Weighted Average Exposure

  More +
• ISSN:
  2398-7308
• Document Type:
  Text
• Funding:
  Cooperative Agreement
• Genre:
  Journal Article
• Place as Subject:
  Maryland ; Massachusetts ; OSHA Region 1 ; OSHA Region 3 ; Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  34-44
• Volume:
  63
• Issue:
  1
• NIOSHTIC Number:
  nn:20053494
• Citation:
  Ann Work Expo Health 2019 Jan; 63(1):34-44
• Contact Point Address:
  Anila Bello, Department of Public Health, University of Massachusetts Lowell, 61 Wilder St, Lowell, MA 01854, USA
• Email:
  anila_bello@uml.edu
• CAS Registry Number:
  Quartz (SiO2) (CAS RN 14808-60-7)
• Federal Fiscal Year:
  2019
• NORA Priority Area:
  Construction
• Performing Organization:
  CPWR - The Center for Construction Research and Training, Silver Spring, Maryland
• Peer Reviewed:
  True
• Start Date:
  20090901
• Source Full Name:
  Annals of Work Exposures and Health
• End Date:
  20240831
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:df61c9d05db89e947ec5cf5007ab00a4f382bc26326d80003a58e690da8e3974bafb344bdff670f97794b40175cd87919a924794fcb5456583de119e5e57a6f7
• Download URL:
  https://stacks.cdc.gov/view/cdc/216235/cdc_216235_DS1.pdf
• File Type:
  [PDF - 941.62 KB ]