Annals of Occupational Hygiene Advance Access originally published online on December 3, 2007
Annals of Occupational Hygiene 2008 52(1):9-21; doi:10.1093/annhyg/mem056
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Published by Oxford University Press on behalf of the British Occupational Hygiene Society
Ultrafine and Respirable Particles in an Automotive Grey Iron Foundry
1 Division of Applied Research and Technology, National Institute for Occupational Safety and Health, 4676 Columbia Parkway, MS-R3, Cincinnati, OH 45226, USA
2 Department of Occupational and Environmental Health, University of Iowa, 102 IREH, 100 Oakdale Campus, Iowa City, IA 52242-5000, USA
3 International Truck and Engine Corporation, 4201 Winfield Road, Warrenville, IL 60555, USA
* Author to whom correspondence should be addressed. Tel: +1-319-335-4213; fax: +1-319-335-4225; e-mail: william-heitbrink{at}uiowa.edu
Ultrafine particle number and respirable particle mass concentrations were measured throughout an automotive grey iron foundry during winter, spring and summer using a particle concentration mapping procedure. Substantial temporal and spatial variability was observed in all seasons and attributed, in part, to the batch nature of operations, process emission variability and frequent work interruptions. The need for fine mapping grids was demonstrated, where elevations in particle concentrations were highly localized. Ultrafine particle concentrations were generally greatest during winter when incoming make-up air was heated with direct fire, natural gas burners. Make-up air drawn from roof level had elevated respirable mass and ultrafine number concentrations above ambient outdoor levels, suggesting inadvertent recirculation of foundry process emissions. Elevated respirable mass concentrations were highly localized on occasions (e.g. abrasive blasting and grinding), depended on the area within the facility where measurements were obtained, but were largely unaffected by season. Particle sources were further characterized by measuring their respective number and mass concentrations by particle size. Sources that contributed to ultrafine particles included process-specific sources (e.g. melting and pouring operations), and non-process sources (e.g. direct fire natural gas heating units, a liquid propane-fuelled sweeper and cigarette smoking) were additionally identified.
Received April 6, 2007; in final form October 9, 2007