Vainiotalo S, Peltonen Y, Ruonakangas A, Pfäffli P
Department of Industrial Hygiene and Toxicology, Finnish Institute of Occupational Health, Helsinki, Finland.
Environ Health Perspect. 1999 Feb;107(2):133-40. doi: 10.1289/ehp.99107133.
We studied customer exposure during refueling by collecting air samples from customers' breathing zone. The measurements were carried out during 4 days in summer 1996 at two Finnish self-service gasoline stations with "stage I" vapor recovery systems. The 95-RON (research octane number) gasoline contained approximately 2.7% methyl tert-butyl ether (MTBE), approximately 8.5% tert-amyl methyl ether (TAME), approximately 3.2% C6 alkyl methyl ethers (C6 AMEs), and 0.75% benzene. The individual exposure concentrations showed a wide log-normal distribution, with low exposures being the most frequent. In over 90% of the samples, the concentration of MTBE was higher (range <0.02-51 mg/m3) than that of TAME. The MTBE values were well below the short-term (15 min) threshold limits set for occupational exposure (250-360 mg/m3). At station A, the geometric mean concentrations in individual samples were 3.9 mg/m3 MTBE and 2. 2 mg/m3 TAME. The corresponding values at station B were 2.4 and 1.7 mg/m3, respectively. The average refueling (sampling) time was 63 sec at station A and 74 sec at station B. No statistically significant difference was observed in customer exposures between the two service stations. The overall geometric means (n = 167) for an adjusted 1-min refueling time were 3.3 mg/m3 MTBE and 1.9 mg/m3 TAME. Each day an integrated breathing zone sample was also collected, corresponding to an arithmetic mean of 20-21 refuelings. The overall arithmetic mean concentrations in the integrated samples (n = 8) were 0.90 mg/m3 for benzene and 0.56 mg/m3 for C6 AMEs calculated as a group. Mean MTBE concentrations in ambient air (a stationary point in the middle of the pump island) were 0.16 mg/m3 for station A and 0.07 mg/m3 for station B. The mean ambient concentrations of TAME, C6 AMEs, and benzene were 0.031 mg/m3, approximately 0.005 mg/m3, and approximately 0.01 mg/m3, respectively, at both stations. The mean wind speed was 1.4 m/sec and mean air temperature was 21 degreesC. Of the gasoline refueled during the study, 75% was 95 grade and 25% was 98/99 grade, with an oxygenate (MTBE) content of 12.2%.
我们通过收集顾客呼吸区域的空气样本，研究了加油过程中顾客的接触情况。测量于1996年夏季的4天内在芬兰的两个配备“第一阶段”油气回收系统的自助加油站进行。95号研究法辛烷值汽油含有约2.7%的甲基叔丁基醚（MTBE）、约8.5%的叔戊基甲基醚（TAME）、约3.2%的C6烷基甲基醚（C6 AMEs）和0.75%的苯。个体接触浓度呈现出广泛的对数正态分布，低接触最为常见。在超过90%的样本中，MTBE的浓度（范围<0.02 - 51毫克/立方米）高于TAME。MTBE的值远低于职业接触设定的短期（15分钟）阈值限值（250 - 360毫克/立方米）。在加油站A，单个样本中的几何平均浓度为MTBE 3.9毫克/立方米和TAME 2.2毫克/立方米。加油站B的相应值分别为2.4和1.7毫克/立方米。加油站A的平均加油（采样）时间为63秒，加油站B为74秒。两个加油站之间顾客接触情况未观察到统计学上的显著差异。调整后的1分钟加油时间的总体几何平均值（n = 167）为MTBE 3.3毫克/立方米和TAME 1.9毫克/立方米。每天还收集一个综合呼吸区域样本，相当于20 - 21次加油的算术平均值。综合样本（n = 8）中的总体算术平均浓度，苯为0.90毫克/立方米，C6 AMEs作为一组计算为0.56毫克/立方米。加油站A环境空气中MTBE的平均浓度为0.16毫克/立方米，加油站B为0.07毫克/立方米。两个加油站TAME、C6 AMEs和苯的平均环境浓度分别约为0.031毫克/立方米、约0.005毫克/立方米和约0.01毫克/立方米。平均风速为1.4米/秒，平均气温为21摄氏度。在研究期间加油的汽油中，75%为95号，25%为98/99号，含氧化合物（MTBE）含量为12.2%。
