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OSH-DB Search Results
- Accession_Number:
- 10000631
- Title:
- Hierarchical Cluster Analysis Applied to Workers' Exposures in Fiberglass Insulation Manufacturing
- Author(s):
- Wu, J-D. ; Milton, D. K. ; Hammond, S. K. ; Spear, R. C.
- Reference:
- Annals of Occupational Hygiene, Vol. 43, No. 1, pages 43-55, 22 references
- Pubdate:
- January 1999
- Subdate:
- 0000/00/00
- Keywords:
- Fiberglass-industry / Industrial-hygiene / Exposure-assessment / Insulation-workers / Endotoxins / Phenols / Formaldehydes / Occupational-exposure
- Abstract:
- A study was conducted to explore the application of cluster analysis to the characterization of multiple exposures in industrial hygiene practice and to compare exposure groupings based on the result from cluster analysis with that based on nonmeasurement-based approaches commonly used in epidemiology. Cluster analysis was performed for 37 workers simultaneously exposed to endotoxin, phenolic compounds and formaldehyde in fiberglass insulation manufacturing. A total of 393 half-shift personal air samples were collected from the 37 workers in four work groups (two production groups and two maintenance groups) for 5 to 6 days each. Two measurements were taken per day for almost all workers. Worker exposures were measured by taking the personal air samples and recording time-activity worklogs. Different clustering algorithms, including complete-linkage (or farthest-neighbor), single-linkage (or nearest-neighbor), group-average, and model-based clustering approaches, were used to construct the tree structures from which clusters could be formed. Differences were observed between the exposure clusters constructed by these different clustering algorithms. When contrasting the exposure classification based on tree structures with that based on nonmeasurement-based information, the results indicated that the exposure clusters identified from the tree structures had little in common with the classification results from either the traditional exposure zone or the work group classification approach. In terms of the defining homogeneous exposure groups or from the standpoint of health risk, some toxicological normalization in the components of the exposure vector appeared to be required in order to form meaningful exposure groupings from cluster analysis. The authors conclude that it remains important to see if the lack of correspondence between exposure groups based on epidemiological classification and measurement data is a peculiarity of the data or a more general problem in multivariate exposure analysis. [OSHDB]
- Copyright (c) 1994-2003, Information Ventures, Inc.
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