Respiratory Diseases and Exposure to Elongated Mineral Particles in Taconite Ore Processing

Details

• Personal Author:
  Alexander B ; Maclehose R ; Mandel J ; Ramachandran G ; Shao Y
• Description:
  The primary research question addressed in this work is whether long-term on-site exposure to non-asbestiform EMP contributes to the development of mesothelioma and lung cancer observed in the taconite mines. If so, which EMP exposure metric (what size range of the study EMP) is most associated with the mesothelioma cases among taconite worker population. We reconstructed the historical NIOSH EMP exposures of workers in Minnesota taconite industry from 1955-2010 based on 751 historical and 1285 present-day EMP measurements using two different reconstruction strategies, one based on only historical and present-day EMP data, and the other one further borrowed the time-trend information from the historical dust reconstruction study. Each of the strategies generated a job exposure matrix (JEM) for the NIOSH defined EMP. These two different JEMs (by mine, department and year for NIOSH defined EMP) set the foundation for calculating life-time exposure to NIOSH-EMP for taconite workers in epidemiological studies. The different JEMs also creates research opportunities for investigating how the selection of different exposure reconstruction strategies would affect final risk estimates in epidemiological studies. A variety of dimensions (lengths and widths) of elongate mineral particles (EMP) have been proposed as being related to health effects such as mesothelioma and lung cancer. The goal of this study was to develop a mathematical approach for deriving numerical conversion factors (CFs) between these exposure metrics. The conversion factor derivation study focused on creating reasonable conversion factors (CFs) between EMPs of different size ranges based on our understanding on how the overall EMP size would be distributed at different locations in taconite mines. We sent all 1285 achieved EMP samples to an accredited lab for ISO-TEM analysis, obtained size information for 11,190 single EMP, literature-reviewed possible size distribution assumptions and developed a Bayesian model for distribution plot prediction. The comprehensive EMP exposure assessment conducted in this study, particularly the mathematical relationships between the NIOSH EMP and other EMP definitions using the new ISO-TEM results, provides the basis of classification of workers into JEMs based on alternate definitions of EMP for epidemiological studies of mesothelioma, lung cancer, and non-malignant respiratory disease. This mesothelioma case-control study focused on investigating the association between the long-term exposures to non-asbestiform EMP and the development of mesothelioma observed in the taconite mines. Compared to the 2010 study, case ascertainment was updated using the Minnesota Cancer Surveillance System (MCSS). Secondly, eight different EMP JEMs were used in the study to estimate worker's cumulative exposures to EMP of different size ranges. The result of this study showed an association between mesothelioma and employment duration and possibly NIOSH EMP exposure in taconite mining and processing. This study also found a possible association between mesothelioma and cumulative exposure to Suzuki EMP and cleavage fragments in the Minnesota taconite worker population. This provides epidemiological evidence in support the long-term speculation that short EMP may also be implicated in development of mesothelioma. [Description provided by NIOSH]
• Subjects:
  Epidemiology Lung Lung Diseases Minerals Mining Neoplasms Occupational Exposure Occupational Health Respiratory System Respiratory Tract Diseases Safety

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• Keywords:
  JEM Job Exposure Matrix Lung Cancer Mesothelioma Mineral Processing Occupational Exposure Taconite
• Series:
  Grant Final Reports
• Publisher:
  National Institute for Occupational Safety and Health
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Final Grant Report
• Place as Subject:
  Maryland ; Minnesota ; OSHA Region 3 ; OSHA Region 5
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  OEP - Office of Extramural Programs
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  1-98
• NIOSHTIC Number:
  nn:20060975
• NTIS Accession Number:
  PB2022-100358
• Citation:
  Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, R01-OH-010418, 2019 Sep; :1-98
• Contact Point Address:
  Gurumurthy Ramachandran, Bloomberg School of Public Health, Johns Hopkins University, E 6634, 615 N. Wolfe Street, Baltimore, MD 21205
• Email:
  gramach5@jhu.edu
• CAS Registry Number:
  Taconite (CAS RN 12249-26-2)
• Federal Fiscal Year:
  2019
• NORA Priority Area:
  Mining
• Performing Organization:
  Johns Hopkins University, Baltimore, Maryland
• Peer Reviewed:
  False
• Start Date:
  20140501
• Source Full Name:
  National Institute for Occupational Safety and Health
• End Date:
  20180715
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:4684afda48f03d9729de067bacb35135332428528b38d2e1530881383d104663e88fe65eb832c01be989d926866b45bfcbe75eef9e7ecff459df52be01c3a750
• Download URL:
  https://stacks.cdc.gov/view/cdc/219017/cdc_219017_DS1.pdf
• File Type:
  [PDF - 865.72 KB ]