Reconstructing Historical Exposures to Respirable Dust and Respirable Silica in the Taconite Mining Industry for 1955–2010

Details

• Personal Author:
  Alexander BH ; Hwang J ; MacLehose RF ; Mandel JH ; Ramachandran G ; Raynor PC ; Shao Y
• Description:
  The goal of this study was to reconstruct the historical respirable silica (RS) and respirable dust (RD) exposures of workers in the Minnesota taconite industry from 1955 to 2010 as part of several epidemiological studies for assessing the association between exposure to components of taconite dusts and the development of respiratory diseases. A job-exposure matrix (JEM) was developed that uses 9127 RS and 19 391 RD occupational hygiene historical measurements. Historical RS and RD data were extracted from several sources and were grouped into seven mines and then into eight departments [Concentrating, Crushing, Janitor, Mining, Office/control room, Pelletizing, Shop (mobile), and Shop (stationary)]. Within each department, we applied a two-level random-intercept regression model which assumes that the natural log of Y (RD or RS concentration) changes over time at a constant rate. Among all predicted RD and RS values, we found that larger RD values were located in the following departments: Crushing, Concentrating, Pelletizing, and Shop (mobile). Larger RS values were located only in either Crushing or Shop (mobile). The annual rates of change for historical RD and RS exposures were between -3.3 and 3.2%. The silica percentage in the dust varied by mine/department with the highest value of 29.3% in Mine F (Crushing) and the lowest value of 2.1% in Mine B (Pelletizing). The predicted historical RD and RS arithmetic mean exposures ranged between 0.075 and 3.14 mg m-3, and between <0.005 and 0.36 mg m-3, respectively. The result of this study is a JEM by mine, department, and year for RD and RS for epidemiological studies. [Description provided by NIOSH]
• Subjects:
  Dust Environmental Exposure Epidemiology Lung Diseases Minerals Mining Occupational Health Respiratory Tract Diseases Risk Assessment Risk Factors Safety Silicon Dioxide Workplace

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• Keywords:
  Analytical Processes Author Keywords: Job-exposure Matrix (JEM) Dust Exposure Exposure Assessment Exposure Levels JEM Job Exposure Matrix Mathematical Models Mineral Dusts Models Particle Size Analysis Pulmonary System Disorders Respirable Dust Respirable Silica Respiratory System Disorders Retrospective Exposure Reconstruction Risk Factors Silica Silica Dusts Statistical Analysis Taconite Taconite Mining Work Environment Worker Health Workers

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• ISSN:
  2398-7308
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  Maryland ; Minnesota ; Oklahoma ; OSHA Region 3 ; OSHA Region 5 ; OSHA Region 6
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  459-471
• Volume:
  66
• Issue:
  4
• NIOSHTIC Number:
  nn:20064124
• Citation:
  Ann Work Expo Health 2022 Apr; 66(4):459-471
• Contact Point Address:
  Gurumurthy Ramachandran, Department of Environmental Health and Engineering, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA
• Email:
  gramach5@jhu.edu
• CAS Registry Number:
  Silica (CAS RN 7631-86-9) ; Taconite (CAS RN 12249-26-2)
• Federal Fiscal Year:
  2022
• Performing Organization:
  Johns Hopkins University, Baltimore, Maryland
• Peer Reviewed:
  True
• Start Date:
  20140501
• Source Full Name:
  Annals of Work Exposures and Health
• End Date:
  20180715
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:58cce9bce7051acad06372544411c07103ad15f6d6088d948dd12b3cf3bcf6987a9c1eb067a7499f220b8273d30e1211b08398d3c5d4cd7b5fda4f9e99b239d1
• Download URL:
  https://stacks.cdc.gov/view/cdc/222638/cdc_222638_DS1.pdf
• File Type:
  [PDF - 1.34 MB ]