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Inhalatory isocyanate exposure in different occupational settings in the Netherlands.
Pronk-A; Bobeldijk-I; Tielemans-E; Deddens-J; Heederik-D; Preller-L
IOHA 2005. 6th International Scientific Conference of the International Occupational Hygiene Association, 19-23 September, 2005, Pilanesberg National Park, North West Province, South Africa. Geneva, Switzerland: World Health Organization, 2005 Sep; :182
Isocyanates are among the most commonly identified causes of occupational asthma. Despite their widespread use and serious health consequences a lack of knowledge on the relationship between exposure and disease still exists. This is partly due to the wide variety of isocyanate compounds in different occupational settings, of which the relative toxicity is unknown. For a large-scale epidemiological study on isocyanate exposure and related health effects, inhalatory isocyanate exposure has been monitored in different occupational settings in the Netherlands. Task based personal inhalatory samples have been taken in the breathing zone of car body repair shop workers (480 samples) and foundry workers (80 samples). Samples were taken using impingers with toluene and di-n-butylamine as a reagent. A large number of different isocyanate related tasks has been monitored to identify relevant tasks. Samples have been analysed by LC-MS for detection of products of thermal degradation (monoisocyanates and aminoisocyanates) in addition to isocyanate monomers and oligomers. A large proportion of the samples did not contain detectable isocyanate levels. The most dominant monomer and oligomer were 1,6-hexamethylene diisocyanate (1,6-HDI) and isocyanurate, respectively. These 1,6-HDI based di and poly isocyanates have been found mainly during the following tasks: spray painting of polyurthane (PU) topcoats > spray painting of PU primers >> cleaning of spray gun, sanding and mounting of cars >> mixing of paint. Geometric mean and standard deviations for spraying of polyurethane (PU) top coat and PU primers were 2.21 (3.81) and 0.47 (3.91) ug/m3 air for 1.6-HDI and 29.36 (7.78) and 0.90 (6.45) ug/m3 air (expressed in 1,6-HDI units) for isocyanurate, respectively. Thermal degradation products were predominantly found during welding. For foundry workers, exposure to 4,4-MDI and some thermal degradation products were incidentally detectable. Large variability within workers and tasks complicates classification of spray painters into exposure sub groups. Therefore, the study will be extended to other spray painting industries with possibly other exposure patterns and higher levels. Currently some 100-120 samples are being collected from various industrial spray painting industries. Exposure data for different categories of isocyanate compounds will be used in epidemiological analyses.
Isocyanates; Occupational-exposure; Inhalants; Inhalation-studies; Bronchial-asthma; Occupational-diseases; Occupational-health; Diseases; Epidemiology; Breathing-zone; Workers; Worker-health; Sampling; Foundry-workers; Spray-painting; Exposure-assessment
Abstract; Conference/Symposia Proceedings
IOHA 2005. 6th International Scientific Conference of the International Occupational Hygiene Association, 19-23 September, 2005, Pilanesberg National Park, North West Province, South Africa