A Study of Respirable Silica in Underground Coal Mines: Particle Characteristics

Details

• Personal Author:
  Keles C ; Sarver E
• Description:
  Respirable crystalline silica is now considered to be a major culprit of resurgent lung disease among US coal miners-especially in central Appalachia-though questions remain regarding the specific circumstances around exposure to it. As part of a larger investigation of dust in 15 US coal mines, a recent study examined the silica content in both the respirable mine dust samples and the samples of respirable dust generated in the laboratory from primary source materials (i.e., coal and rock strata and rock dusting products). It concluded the rock strata that is being drilled for roof bolting or is being cut along with the coal is the most significant source of respirable silica in many mines, which is consistent with the expectations based on other scattered datasets. However, little information is available on the characteristics of respirable silica particles which might be important for understanding the exposure risks better. In the current study, which represents another part of the aforementioned investigation in 15 mines, scanning electron microcopy with energy dispersive X-ray spectroscopy (SEM-EDX) were used to analyze the size and surface condition (i.e., degree of surface-associated clay) of 1685 silica particles identified in 58 respirable mine dust samples. The results indicated that silica is typically finer in locations nearby to drilling and cutting activities than it is in other locations within a mine, but the silica in the Central Appalachian mines is not necessarily finer than it is in the mines in other regions. An analysis of the particle surfaces revealed that respirable silica in coal mines often does not occur as "free", high-purity particles. Rather, there can be a range of occurrences including silica particles having a thin "occlusion" layer of clay, silica within agglomerates that can also contain other particle types including clays, or even silica ingrained within other particles such as coal. [Description provided by NIOSH]
• Subjects:
  Dust Occupational Health Particulate Matter Safety Silicon Dioxide
• Keywords:
  Author Keywords: Respirable Crystalline Silica Coal Dust Coal Mines Crystalline Silica Particle Size Particle Surfaces RCMD RCS Respirable Coal Mine Dust Respirable Dust Scanning Electron Microcopy With Energy Dispersive X-ray Spectroscopy Scanning Electron Microscopy SEM-EDX Silica Dusts Spectroscopes

  More +
• ISSN:
  2075-163X
• Document Type:
  Text
• Funding:
  Contract
• Genre:
  Journal Article
• Place as Subject:
  OSHA Region 3 ; Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  12
• Issue:
  12
• NIOSHTIC Number:
  nn:20067773
• Citation:
  Minerals 2022 Dec; 12(12):1555
• Contact Point Address:
  Cigdem Keles, Mining & Minerals Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
• Email:
  cigdem@vt.edu
• CAS Registry Number:
  Quartz (SiO2) (CAS RN 14808-60-7)
• Federal Fiscal Year:
  2023
• Performing Organization:
  Virginia Polytechnic Institute & State University
• Peer Reviewed:
  True
• Start Date:
  20190901
• Source Full Name:
  Minerals
• End Date:
  20210831
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:1f86a09c780540047c93f47f158e85f9039fc74e9af8f105aa5af9d3def4223701f605718bef1fda9d12eacb74f2c6c6d8e9c5e5348783c927a55c4fc66f29df
• Download URL:
  https://stacks.cdc.gov/view/cdc/230033/cdc_230033_DS1.pdf
• File Type:
  [PDF - 3.35 MB ]