The concentration of nitrous oxide (N2O) in urine was determined in 145 subjects (anesthetists, surgeons, and nurses) in operating theaters. The time-weighted average environmental concentration of N2O (breathing zone) was measured by means of personal passive samplers. The analyses were performed by the head space method, using a Hewlett-Packard 5880 A gas chromatograph with a Hewlett-Packard 5970 A Mass Selective Detector. A significant correlation was found between the N2O concentration in urine produced during the shift (Cū, μg/L) and N2O environmental concentration (Cī, ppm) (Cū = 0.582 Cī + 5.47; r = 0.89). The results show that the urinary concentration can be used as an appropriate biological exposure indicator. The authors suggest a Biological Exposure Index (BEI) of 55 μg/L of N2O in urine. This is the biological value obtained after four hours of an average environmental exposure to 100 ppm.© Taylor & Francis Group, LLC.
ASJC Scopus subject areas
- Public Health, Environmental and Occupational Health