Respirable Coal Mine Dust Research: Characterization and Toxicity

Details

• Personal Author:
  Salinas Torres VP
• Description:
  Coal mine workers are continuously exposed to respirable coal mine dust (RCMD) in workplaces. RCMD is released into the mine air during cutting, drilling, blasting, and transportation. Exposure to RCMD is a severe health hazard that affects thousands of miners in the United States. When dust particles are inhaled, the respirable fraction can be deposited in the lungs' deeper region, deteriorating their gas exchange capacity. Continued exposure over the years to RCMD can lead to progressive pulmonary diseases, such as coal worker's pneumoconiosis (CWP), silicosis, mixed dust pneumoconiosis, dust-related diffuse fibrosis (DDF), and progressive massive fibrosis (PMF). RCMD characteristics and their relations with dust toxicity need further research to understand the adverse exposure effects of RCMD. Different variables may be involved in RCMD toxicity, such as geographic location and dust sources. The map of the coal workers' pneumoconiosis death rates from 2001-2010 in the U.S. shows a noticeable area with higher rates in the eastern side of the country. This region is well known as the Appalachian Mountains. The geographic clustering of coal workers' pneumoconiosis (CWP) suggests that RCMD in the Appalachian region may exhibit more toxicity than in other geographic regions like the Rocky Mountains. Additionally, dust particles in the mine coming from different sources might have different compositions, which may make the dust particles display different toxicity when exposed to the lungs. RCMD generated by cutting host rock may be more toxic than the dust from cutting coal seam. This study investigates the RCMD characteristics and toxicity based on geographic locations and sources. Dissolution experiments in simulated lung fluids (SLFs) and in-vitro response were conducted to determine the toxicity level of samples collected from 5 mines in the Rocky Mountains and Appalachian regions. Dust characteristics were investigated using Fourier-transform infrared spectroscopy, scanning electron microscope, BET method, total microwave digestion, X-ray diffraction, and X-ray photoelectron spectroscopy. Inductively coupled plasma mass spectrometry (ICP-MS) was conducted to determine the concentration of metals dissolved in the SLFs. Finer particle sizes and higher mineral and elemental contents were found in samples from the Appalachian regions. Host rock also showed significantly higher elemental and mineral content than coal. Si, Al, Fe, Cu, Ba, Sr, and Pb were found in dissolution experiments. No trends indicated higher dissolutions in the Appalachian region, but higher elemental bio-accessibility in samples from the host rock was found when dust was exposed to artificial lysosomal fluid (ALF). In-vitro studies indicated a pro-inflammatory response, especially in macrophage cells. The toxicity of the samples based on the metal dissolutions in SLFs and the in-vitro inflammatory response could not be related to the geographic location but to the source. Therefore, the higher incidence of lung diseases in the Appalachian region may be related to other factors like exposure to RCMD, the particle size distribution of the actual RCMD in each mine, and the mineral contributions from the different sources in the mine. Still, the inflammatory response obtained in the studied cells suggests their possible participation in pneumoconiosis and lung diseases-development. [Description provided by NIOSH]
• Subjects:
  Coal Coal Mining Dust Immune System Lung Lung Diseases Mining Occupational Health Respiratory System Respiratory Tract Diseases Safety

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• Keywords:
  Author Keywords: RCMD Black Lung Disease Coal Dust Coal Workers Pneumoconiosis Dust Analysis Immune Reaction In Vitro Studies In Vitro Toxicity Studies Lung Fibrosis Respirable Dust Respirable Dust Characteristics Simulated Lung Fluids

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• Publisher:
  New Mexico Institute of Mining and Technology
• Document Type:
  Text
• Funding:
  Contract
• Genre:
  Thesis
• Place as Subject:
  New Mexico ; OSHA Region 6
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  1-77
• NIOSHTIC Number:
  nn:20068716
• Citation:
  Socorro, NM: New Mexico Institute of Mining and Technology, 2022 Dec; :1-77
• Federal Fiscal Year:
  2023
• Performing Organization:
  New Mexico Institute of Mining and Technology
• Peer Reviewed:
  False
• Start Date:
  20190915
• Source Full Name:
  Respirable coal mine dust research: characterization and toxicity
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:c643d68fb2629dbc6a2ca71b08a996c57b59012acb7433faaa576c4fae75a129b5a1a580673c9a699595834b7137847b0c39d0d8cce2dc4be9d2907b33257af7
• Download URL:
  https://stacks.cdc.gov/view/cdc/207302/cdc_207302_DS1.pdf
• File Type:
  [PDF - 3.91 MB ]