Radboud Institute for Health Sciences, Radboudumc, Nijmegen, the Netherlands.
Radboud Institute for Health Sciences, Radboudumc, Nijmegen, the Netherlands.
Environ Res. 2019 Nov;178:108670. doi: 10.1016/j.envres.2019.108670. Epub 2019 Aug 19.
Exposure to benzene, toluene and p-, m-, o-xylene (BTX) was studied in 29 gas station attendants and 16 office workers in Sri Lanka. The aim of this study was to assess the exposure level and identify potential exposure mitigating measures. Pre- and post-shift samples of end-exhaled air were collected and analysed for BTX on a thermal desorption gas chromatography mass spectrometry system (TD-GC-MS). Urine was collected at the same timepoints and analysed for a metabolite of benzene, S-phenyl mercapturic acid (SPMA), using liquid chromatography-mass spectrometry (LC-MS). Environmental exposure was measured by personal air sampling and analysed by gas chromatography flame ionization detection (GC-FID). Median (range) breathing zone air concentrations were 609 (65.1-1960) μg/m for benzene and 746 (<5.0-2770) μg/m for toluene. Taking into account long working hours, 28% of the measured exposures exceeded the ACGIH threshold limit value (TLV) for an 8-h time-weighted average of 1.6 mg/m for benzene. Xylene isomers were not detected. End-exhaled air concentrations were significantly increased for gas station attendants compared to office workers (p < 0.005). The difference was 1-3-fold in pre-shift and 2-5-fold in post-shift samples. The increase from pre-to post-shift amounted to 5-15-fold (p < 0.005). Pre-shift BTX concentrations in end-exhaled air were higher in smokers compared to non-smokers (p < 0.01). Exposure due to self-reported fuel spills was related to enhanced exhaled BTX (p < 0.05). The same was found for sleeping at the location of the gas station between two work-shifts. Benzene in end-exhaled air was moderately associated with benzene in the breathing zone (r = 0.422; p < 0.001). Median creatinine-corrected S-phenyl mercapturic acid (SPMA) was similar in pre- and post-shift (2.40 and 3.02 μg/g) in gas station attendants but increased in office workers (from 0.55 to 1.07 μg/g). In conclusion, working as a gas station attendant leads to inhalation exposure and occasional skin exposure to BTX. Smoking was identified as the most important co-exposure. Besides taking preventive measure to reduce exposure, the reduction of working hours to 40 h per week is expected to decrease benzene levels below the current TLV.
本研究旨在评估接触水平并确定潜在的暴露缓解措施。在轮班前和轮班后收集呼出的终末空气样本，并使用热解吸气相色谱-质谱联用系统（TD-GC-MS）分析 BTX。同时收集尿液，并使用液相色谱-质谱法（LC-MS）分析苯的代谢物 S-苯巯基尿酸（SPMA）。通过个人空气采样并使用气相色谱火焰离子化检测（GC-FID）进行环境暴露测量。中位数（范围）呼吸区空气浓度为苯 609（65.1-1960）μg/m3，甲苯 746（<5.0-2770）μg/m3。考虑到工作时间长，28%的测量暴露值超过了 ACGIH 时间加权平均值 1.6mg/m3 的 8 小时阈值限值（TLV）。未检测到二甲苯异构体。与办公室工作人员相比，加油站工作人员的呼出空气中的浓度明显升高（p<0.005）。轮班前和轮班后的样本分别增加了 1-3 倍和 2-5 倍。从轮班前到轮班后的增加量为 5-15 倍（p<0.005）。与非吸烟者相比，吸烟者的轮班前呼出空气中 BTX 浓度更高（p<0.01）。自我报告的燃料溢出导致的暴露与呼出的 BTX 增加有关（p<0.05）。在两班之间在加油站睡觉也是如此。呼出空气中的苯与呼吸区的苯中度相关（r=0.422；p<0.001）。加油站工作人员的轮班前和轮班后的肌酐校正 S-苯巯基尿酸（SPMA）中位数相似（2.40 和 3.02μg/g），但办公室工作人员的 SPMA 中位数增加（从 0.55 到 1.07μg/g）。总之，作为加油站工作人员会导致吸入和偶尔的皮肤接触 BTX。吸烟被确定为最重要的共同暴露因素。除了采取预防措施减少暴露外，预计将工作时间减少到每周 40 小时将使苯水平低于当前的 TLV。
