Bromide and N-acetyl-S-(n-propyl)-L-cysteine in urine from workers exposed to 1-bromopropane solvents from vapor degreasing or adhesive manufacturing.
OBJECTIVE
1-Bromopropane (1-BP) is an alternative for ozone depleting and other solvents; it is used in aerosol products, adhesives, and cleaning solvents. There is concern that 1-BP may be a reproductive and neurological toxicant. Mercapturic acid conjugates are excreted in urine from 1-BP metabolism involving debromination. The main objectives were to evaluate urinary bromide [Br(-)] and N-acetyl-S-(n-propyl)-L-cysteine (AcPrCys) for assessing 1-BP exposure in workers with low exposure.


METHODS
Workers' 1-BP exposures were measured in their breathing zones with gas chromatography-flame ionization detection via NIOSH 1025. Urine specimens were obtained over a 48-h period at five facilities using vapor degreasers and one adhesive manufacturer. All of the workers' urine was collected into composite samples and analyzed separately representing daily time intervals: at work, after work but before bedtime, and upon awakening. Urinary metabolites were analyzed using intra-coupled plasma-mass spectroscopy for Br(-), and high-performance liquid chromatography and electro-spray ionization mass spectroscopy for AcPrCys.


RESULTS
Time-weighted average (TWA) geometric mean (GM) breathing zone concentrations of 1-BP at vapor degreasing facilities were 2.6 and 0.31 ppm, respectively, for workers near degreasers and those remote from degreasers. Urine metabolites showed the same trend as TWA exposures: higher levels were observed for workers near degreasers (48-h GM Br(-) = 8.9 vs. 3.7; 48-h GM AcPrCys = 1.3 vs. 0.12, respectively). Associations of Br(-) and AcPrCys concentrations with 1-BP TWA were statistically significant near degreasers (p < 0.01).


CONCLUSIONS
This study shows that urinary Br(-) and AcPrCys are useful biomarkers of workers' 1-BP exposures using analyses sensitive enough to measure low exposure jobs.
Hanley
Kevin William
KW
National Institute for Occupational Safety and Health, Cincinnati, OH, USA. KHanley@cdc.gov
Petersen
Martin R
MR
Cheever
Kenneth L
KL
Luo
Lian
L
D000111:Acetylcysteine / Q000031:analogs & derivatives* / Q000652:urine; D000328:Adult; D000395:Air Pollutants, Occupational / Q000032:analysis; D001965:Bromides / Q000652:urine*; D004784:Environmental Monitoring; D005260:Female; D006801:Humans; D006842:Hydrocarbons, Brominated / Q000032:analysis; D008297:Male; D008420:Manufactured Materials; D008875:Middle Aged; D016273:Occupational Exposure / Q000032:analysis*; D012959:Socioeconomic Factors; D012997:Solvents / Q000032:analysis*; D013997:Time Factors
D000395:Air Pollutants, Occupational; D001965:Bromides; D006842:Hydrocarbons, Brominated; C520626:N-acetyl-S-propylcysteine; D012997:Solvents; D000111:Acetylcysteine; C118559:1-bromopropane