Detection and characterization of nanoparticles in respirable coal mine dust.

Details

• Personal Author:
  Akinseye T ; Assemi S ; Miller JD ; Pan L ; Sime F ; Wang X
• Description:
  Respirable coal mine dust (RCMD) is a complex mixture of carbonaceous and mineral particles with a variation in size and shape. Accumulation of RCMD in the lungs of underground coal miners results in severe respiratory damage and ultimately progressive pneumoconiosis known as the black lung disease. The occurrence of the black lung disease dropped to a low of 2.1% in 1990s but has increased to 3.1% in 2000s, prompting more research on coal mine dust mitigation. In addition to surveying the impact of new mining technologies on the size of generated dust and exposure measurement, a comprehensive characterization of physico-chemical properties of RCMD particles are essential for a better understanding of the adverse health effects of coal mine dust. Such vital factors include particle size, surface charge, morphology, composition, and agglomeration state. The respirable fraction of RCMD, has been designated as particles < 10 µm in diameter, and almost all studies on the RCMD toxicity have focused on micron-sized particles. However, recent toxicological studies have shown that nanoparticles (particles with one dimension less than 100 nm) can have a magnified toxicity compared to the larger particles with the same chemistry. Nanoparticles have a much higher specific surface area compared to the same mass of larger particles and are thus more reactive. Most micron-size particles can be cleared by the body's defense mechanism. However, inhaled nanoparticles can easily deposit in all regions of the respiratory tract and can translocate to vital organs. Valuable information on size and elemental composition of micron sized RCMD particles has been obtained using electron microscopy, and Energy Dispersive X-ray Spectroscopy (EDX) of individually analyzed particles. The method requires that individual particles be counted and measured separately. In addition, often times the smaller particles are adsorbed on the larger particles and are hard to measure or distinguish. Field-flow fractionation is a family of elution and separation techniques, where the particles can be separated and analyzed in narrow fractions, and can facilitate the characterization of nanoparticles in RCMD. In this study, Asymmetrical Field-flow Fractionation (AsFlFFF) was used to separate and obtain the size distribution of nano-sized RMCD samples. RCMD samples were collected at different coal mines on polycarbonate (PC) filter papers. The collected samples were initially characterized for size and composition using Scanning electron microscopy (SEM) and Dynamic Light Scattering (DLS). In addition a methodology was developed to analyze the nanoparticles in RCMD using the AsFlFFF. Results obtained from the three techniques clearly demonstrated the presence of nanoparticles in RCMD samples. Nanoparticles with diameter below 100 nm were only detected by AsFlFFF. Data on the size distribution, morphology and elemental composition of nanoparticles in RCMD are presented. The challenges, potential, and limitations of AsFlFFF for RCMD analysis are discussed. [Description provided by NIOSH]
• Subjects:
  Coal Coal Mining Dust Lung Lung Diseases Mining Occupational Health Particulate Matter Radiography Respiratory System Respiratory Tract Diseases Safety

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• Keywords:
  Mining industry; Coal dust; Respirable dust; Mineral dusts; Black lung disease; Coal workers pneumoconiosis; Particle size; Nanoparticles; X-ray analysis; Scanning electron microscopy
• ISBN:
  9781713845089
• Publisher:
  Society for Mining, Metallurgy & Exploration (SME)
• Document Type:
  Text
• Funding:
  Contract
• Genre:
  Proceedings
• Place as Subject:
  Colorado ; Michigan ; OSHA Region 5 ; OSHA Region 8 ; Utah
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  431-433
• NIOSHTIC Number:
  nn:20065326
• Citation:
  MineXchange: 2022 SME Annual Conference and Expo, February 27-March 2, 2022, Salt Lake City, Utah, preprint 22-080. Englewood, CO: Society for Mining, Metallurgy & Exploration, 2022 Feb; :431-433
• Federal Fiscal Year:
  2022
• Performing Organization:
  Michigan Technological University
• Peer Reviewed:
  False
• Start Date:
  20190901
• Source Full Name:
  MineXchange: 2022 SME Annual Conference and Expo, February 27-March 2, 2022, Salt Lake City, Utah, preprint 22-080
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:8f8a267d8835ef3b11f213ed71bf1c7fe835df3c1f4d45cbc7a2c21114a7effa99cbaee0680b4a67d04da5ccf6799cdf3090b19ebabac41d33723db05117b1f2
• Download URL:
  https://stacks.cdc.gov/view/cdc/248846/cdc_248846_DS1.pdf
• File Type:
  [PDF - 324.30 KB ]