Ong C N, Shi C Y, Chia S E, Chua S C, Ong H Y, Lee B L, Ng T P, Teramoto K
Department of Community, Occupational and Family Medicine, National University of Singapore.
Am J Ind Med. 1994 May;25(5):719-30. doi: 10.1002/ajim.4700250511.
A field study was conducted on 39 male workers exposed to styrene at concentrations below 40 ppm (time weighted average, TWA). Analyses were carried out on environmental air, exhaled air, blood, urine, and two major urinary metabolites of styrene: mandelic acid (MA) and phenylglycoxylic acid (PGA). Head space gas chromatography (GC) with a flame ionization detector (FID) was used for determination of styrene in blood and urine. Postexposure exhaled air was analyzed using capillary GC. Environmental styrene exposure was measured by personal sampling using carbon cloth personal samplers. Urinary metabolites of styrene were determined by high pressure liquid chromatograph (HPLC). When the end-of-shift breath, blood, and urine styrene levels were compared with environmental TWA values, blood styrene correlated best with styrene in air (r = 0.87), followed by breath styrene (r = 0.76). Poor correlation (r = 0.24) was observed between environmental styrene exposure and urine styrene. When styrene metabolites were compared with environmental styrene, the sum of urinary MA and PGA correlated better with styrene in air than MA or PGA alone. The correlations between urinary metabolites and environmental styrene improved when corrected for the specific gravity of urine. Even better correlations were observed when the urinary metabolites were corrected for creatinine. The correlation coefficients for environmental styrene and end-of-shift MA, PGA, and MA+PGA were 0.83, 0.84, and 0.86, respectively. The correlation coefficients between environmental styrene and next morning urinary metabolites fell to 0.47, 0.61, and 0.65 for MA, PGA, and MA+PGA, respectively. These results suggest that determination of the total MA and PGA in urine samples is preferred than separate measurements of MA or PGA. The good correlation between environmental exposure and styrene in the exhaled air also suggests that breath styrene level can be a useful indicator for low level styrene exposure, as the method is specific, noninvasive, and rapid. Urinary styrene seems to be a less reliable indicator for low level styrene exposure.
对39名暴露于浓度低于40 ppm（时间加权平均值，TWA）苯乙烯环境中的男性工人进行了一项现场研究。对环境空气、呼出气体、血液、尿液以及苯乙烯的两种主要尿液代谢物：扁桃酸（MA）和苯乙醇酸（PGA）进行了分析。采用带火焰离子化检测器（FID）的顶空气相色谱法（GC）测定血液和尿液中的苯乙烯。使用毛细管GC分析暴露后呼出的气体。通过使用碳布个人采样器进行个人采样来测量环境苯乙烯暴露情况。苯乙烯的尿液代谢物通过高压液相色谱仪（HPLC）测定。当将轮班结束时的呼气、血液和尿液中的苯乙烯水平与环境TWA值进行比较时，血液中的苯乙烯与空气中的苯乙烯相关性最佳（r = 0.87），其次是呼气中的苯乙烯（r = 0.76）。环境苯乙烯暴露与尿液苯乙烯之间的相关性较差（r = 0.24）。当将苯乙烯代谢物与环境苯乙烯进行比较时，尿液中MA和PGA的总和与空气中苯乙烯的相关性比单独的MA或PGA更好。校正尿液比重后，尿液代谢物与环境苯乙烯之间的相关性有所改善。当对尿液代谢物进行肌酐校正时，观察到的相关性更好。环境苯乙烯与轮班结束时的MA、PGA和MA + PGA的相关系数分别为0.83、0.84和0.86。环境苯乙烯与次日晨尿代谢物之间的相关系数分别降至MA为0.47、PGA为0.61、MA + PGA为0.65。这些结果表明，测定尿液样本中的总MA和PGA比单独测量MA或PGA更可取。环境暴露与呼出气体中苯乙烯之间的良好相关性还表明，呼气苯乙烯水平可作为低水平苯乙烯暴露的有用指标，因为该方法具有特异性、非侵入性且快速。尿液苯乙烯似乎是低水平苯乙烯暴露的较不可靠指标。
