Relationship between the external exposure and biomarker of 1-bromopropane in workplace

摘要

Aims: 1-Bromopropane (1-BP) has been applied as the metal cleaning agents in manufacture industries since the ozone-depletion substances were banned. Exposure of 1-bromopropane has been found in related with the peripheral neuropathy. The ACGIH classified 1-BP as an A3 chemical. Several occupational disease cases due to the 1-BP exposure were confirmed in Japan, USA, China and Taiwan. This study investigated the exposure profiles of workplaces using 1-BP. Also, the 1-BP metabolite, n-acetyl-S-(n-propyl)-L-cysteine (AcPrCys) in urine was quantified to establish the relationship between the external dose and internal dose of 1 -BP. Methods: Three factories that using 1-BP for metal cleaning were investigated. The 1-BP sampling protocol was modified from OSHA Methods No. 1017 and NIOSH No. 1025. The sampling flowrate was set at 200 mL/min. The sampling durations were 6 hours. All samples were analyzed by GC/MS with a method detection limit of 0.84 ppb. The urine samples were collected on the day that the personal air samples collected. n-Acetyl-S-(n-propyl)-L-cysteine (AcPrCys), the 1-BP metabolite, was selected as the biological exposure index (BEI) and quantified by HPLC-MS/MS. The limit of quantitation was 0.023 ng/mL. A total of 100 area and personal air samples and 76 urine samples (before and after the work shift) were collected from three plants. The study was proofed by the Fu Jen Catholic University IRB. Results: The 1-BP concentrations of the 95th percentiles of exposure group (cleaning operation) were ranged from 31.44 to 41.96 ppm for personal samples. The 95th percentile1-BP concentrations of area samples air were ranged from 20.43 to 41.84 ppm. The AcPrCys concentrations in urines were between 11.58 mg/g cre and 4,945.71 mg/g cre before shifts, and the AcPrCys concentrations in urines were from 3.72 mg/g cre to 7,818.26 mg/g cre after shift. The correlation between the after-shift urine AcPrCys concentrations and the 1-BP concentrations of personal air samples was significant (r = 0.679, p = 0.05). This implied that "after-shift" is a better specimen collecting time for 1-BP BEI, AcPrCys. Conclusions: The personal air sampling results exceeded Cal OSHA PEL 5 ppm and ACGIH TLV®-TWA 0.1 ppm. The after-shift urine concentration of AcPrCys was a good biomarker to represent the internal dose of 1-BP exposure. Meanwhile, from the occupational hygiene concern,effective engineering control, respiratory protection program and dermal protection program should be implanted to limit the exposures.