Exposure of healthy subjects with emissions from a gas metal arc welding process: part 1--exposure technique and external exposure.
BACKGROUND
Studies concerning welding fume-related adverse health effects in welders are hampered by the heterogeneity of workplace situations, resulting in complex and non-standardized exposure conditions.


METHODS
In order to carry out welding fume exposure studies under controlled and standardized conditions, the Aachen Workplace Simulation Laboratory was developed. This laboratory consists of an emission room, in which welding fume is produced, and an exposure room in which human subjects are exposed to these fumes. Both rooms are connected by a ventilation system which allows the welding fume concentration to be regulated. Particle mass concentration was measured with a TEOM microbalance and the particle number-size distribution using a Grimm SMPS device.


RESULTS
In a study, which is the subject of this paper, it has been shown that welding fume concentration can easily be regulated between 1 and about 3 mg m(-3). The chosen concentration can be kept constant for more than 8 h. However, transport of the particles from the emission room into the exposure room leads to a change in particle size distribution, which is probably due to coagulation of the fraction of smallest particles.


CONCLUSIONS
The Aachen Workplace Simulation Laboratory is suitable for controlled exposure studies with human subjects.
Institute for Occupational and Social Medicine, Medical Faculty, RWTH Aachen University, Pauwelsstr 30, 52074 Aachen, Germany. pbrand@ukaachen.de
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Brand
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Havlicek
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Steiners
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Holzinger
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Reisgen
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Kraus
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Gube
D000395:Air Pollutants, Occupational / Q000633:toxicity*; D002138:Calibration; D005740:Gases / Q000633:toxicity; D006801:Humans; D016273:Occupational Exposure; D010316:Particle Size; D014896:Welding
D000395:Air Pollutants, Occupational; D005740:Gases