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Mapping particulate matter at the body weld department in an automobile assembly plant.

Authors
Liu-S; Hammond-SK
Source
J Occup Environ Hyg 2010 Oct; 7(10):593-604
NIOSHTIC No.
20038092
Abstract
A respiratory health survey conducted in an assembly plant in 2000-2001 found that welders had elevated rates of self-reported respiratory symptoms compared with painters and assembly workers. Subsequently, the ventilation system was improved at the body weld department. In a follow-up study, particle spatial distributions were analyzed, following a mapping protocol developed specifically for this workplace, to evaluate the effectiveness of the changes. Significant temporal and spatial variations were observed. Temporal variation during a shift was monitored with over-shift stationary sampling at fixed locations. Spatial variation was evaluated with 1-min time-weighted average particle concentrations measured throughout the process areas (212 locations). The arithmetic spatial mean across 212 locations for the respirable particles varied from 305 microg/m(3) to 501 microg/m(3) on 6 sampled days, with a standard deviation of 71 microg/m(3), indicating that the difference between before and after countermeasures must be at least 191 microg/m(3) to be considered statistically significant at the given sample sizes. The available data were not sufficient to evaluate the reduction of the particle concentrations after the countermeasures. The map of particle mass concentration revealed several high concentration areas, requiring further investigation and potentially higher level of controls. Resistance welding needed to be effectively controlled, as it could be the major particle emitting sources in the facility. The map of submicrometer (0.014 microm to 1.0 microm) particle count concentration presented different patterns from that of respirable particle mass concentration, indicating that the submicrometer particles tended to be more evenly distributed over the process areas. Workers not in proximity to intensive welding operations might be exposed to fine particles at levels higher than had traditionally been thought. Mapping was demonstrated to be an effective method to assess particle spatial distributions. A well-designed sampling protocol is critical to achieving the specific aims of a mapping study.
Keywords
Respiratory-system-disorders; Welders; Welders-lung; Automotive-industry; Air-contamination; Air-flow; Work-environment; Air-monitoring; Ventilation; Ventilation-systems; Time-weighted-average-exposure; Particle-counters; Particulate-sampling-methods; Particulates; Sampling-methods; Author Keywords: mapping; particulate matter; temporal and spatial variations; ventilation; welding
Contact
S. Katharine Hammond, Environmental Health Sciences Division, 50 University Hall MC7360, School of Public Health, University of California, Berkeley, CA 94720-7360 USA
CODEN
JOEHA2
Publication Date
20101001
Document Type
Journal Article
Funding Type
Grant
Fiscal Year
2011
NTIS Accession No.
NTIS Price
Identifying No.
Grant-Number-T42-OH-008429
Issue of Publication
10
ISSN
1545-9624
Source Name
Journal of Occupational and Environmental Hygiene
State
CA
Performing Organization
University of California, Berkeley
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