Skip directly to search Skip directly to A to Z list Skip directly to page options Skip directly to site content

NIOSHTIC-2 Publications Search

Search Results

Estimates of historical exposures by phase contrast and transmission electron microscopy in North Carolina USA asbestos textile plants.

Authors
Dement-JM; Myers-D; Loomis-D; Richardson-D; Wolf-S
Source
Occup Environ Med 2009 Sep; 66(9):574-583
NIOSHTIC No.
20036289
Abstract
OBJECTIVES: To develop a job-exposure matrix (JEM) for fibre exposures in three asbestos textile plants and to develop estimates of fibre size-specific exposures. METHODS: Historical dust samples from three North Carolina, USA asbestos textile plants were obtained. Plant specific samples were used to express impinger dust concentrations as fibre concentrations by phase contract microscopy (PCM). Mixed models were used to estimate PCM exposures by plant, department, job and calendar time. Archived membrane filter samples were analysed by transmission electron microscopy (TEM) to determine the bivariate diameter/length distribution of airborne fibres by plant and operation. RESULTS: PCM fibre levels estimated from the models were very high in the 1930s, with some operations having in excess of 200 fibres/ml, and decreased appreciably over time. TEM results for 77 airborne dust samples found that only a small proportion of airborne fibres were measured by PCM (>0.25 microm in diameter and >5 microm in length) and the proportion varied considerably by plant and operation (range 2.9% to 10.0%). The bivariate diameter/length distribution of airborne fibres demonstrated a relatively high degree of variability by plant and operation. PCM adjustment factors also varied substantially across plants and operations. CONCLUSIONS: These data provide new information concerning airborne fibre levels and characteristics in three historically important asbestos textile plants. PCM concentrations were high in the early years and TEM data demonstrate that the vast majority of airborne fibres inhaled by the workers were shorter than 5 microm in length, and thus not included in the PCM-based fibre counts.
Keywords
Airborne-fibers; Asbestos-dust; Dust-exposure; Dust-inhalation; Dust-particles; Exposure-assessment; Exposure-levels; Exposure-methods; Fibrous-dusts; Filter-membranes; Industrial-dusts; Industrial-environment; Industrial-exposures; Industrial-hazards; Industrial-processes; Lung-cells; Lung-disease; Lung-disorders; Lung-irritants; Mathematical-models; Microscopic-analysis; Occupational-exposure; Occupational-hazards; Occupational-health; Occupational-respiratory-disease; Particulate-dust; Pulmonary-system-disorders; Work-environment; Work-operations; Work-practices; Worker-health; Asbestos-fibers
Contact
Professor John M Dement, Division of Occupational and Environmental Medicine, Department of Community and Family Medicine, Duke University Medical Center, 2200 W Main Street, Suite 400, Durham, NC 27705, USA
CODEN
OEMEEM
CAS No.
1332-21-4
Publication Date
20090901
Document Type
Journal Article
Email Address
John.Dement@Duke.edu
Funding Type
Grant
Fiscal Year
2009
NTIS Accession No.
NTIS Price
Identifying No.
Grant-Number-R01-OH-007803
Issue of Publication
9
ISSN
1351-0711
Source Name
Occupational and Environmental Medicine
State
NC; NV
Performing Organization
University of North Carolina, Chapel Hill
TOP