Wilson Michael P, Hammond S Katharine, Nicas Mark, Hubbard Alan E
School of Public Health, University of California Berkeley, Berkeley, California 94720-7360, USA.
J Occup Environ Hyg. 2007 May;4(5):301-10. doi: 10.1080/15459620701258021.
This study evaluated exposures among vehicle repair technicians to hexane, acetone, toluene, and total volatile organic compounds (VOCs). On randomly selected workdays, we observed a characteristic pattern of solvent use among 36 technicians employed in 10 repair shops, each of which used an aerosol solvent product. We obtained quantitative exposure measurements from a subset of nine technicians (employed in three of these shops) who used an aerosol product containing hexane (25-35%), acetone (45-55%), and toluene (5-10%). The time-weighted average (TWA) exposure concentration for task-length breathing zone (BZ) samples (n = 23) was 36 mg/m(3) for hexane, 50 mg/m(3) for acetone, and 10 mg/m(3) for toluene. The TWA area concentrations (n = 49) obtained contemporaneously with BZ samples ranged from 25% to 35% of the BZ concentrations. The solvent emission rate (grams emitted/task time) was correlated with the total VOC exposure concentration (R(2) = 0.45). The proportions of VOCs in the BZ samples were highly correlated (r = 0.89 to 0.95) and were similar to those of the bulk product. Continuous exposure measurements for total VOCs (n = 1238) during 26 tasks produced a mean BZ VOC "pulse" of 394 mg/m(3) within 1 min following initiation of solvent spraying. The geometric mean air speed was 5.2 meters/min in the work areas (n = 870) and was associated with 0.8 air changes per minute in the BZ. The findings suggest that vehicle repair technicians who use aerosol solvent products experience episodic, inhalation exposures to the VOCs contained in these products, and the proportions of VOCs in the breathing zone are similar to those of the bulk product. Because acetone appears to amplify the severity and duration of the neurotoxic effects of n-hexane, products formulated with both hexane and acetone should be avoided. Further evaluation of exposures to VOCs is needed in this industry, along with information on effective alternatives to aerosol solvent products.
本研究评估了汽车维修技术人员对己烷、丙酮、甲苯和总挥发性有机化合物（VOCs）的接触情况。在随机选择的工作日，我们观察了10家维修店中36名技术人员使用溶剂的特征模式，每家维修店都使用一种气溶胶溶剂产品。我们从9名技术人员（来自其中3家维修店）的子集中获得了定量接触测量数据，这些技术人员使用了一种含有己烷（25 - 35%）、丙酮（45 - 55%）和甲苯（5 - 10%）的气溶胶产品。任务时长呼吸带（BZ）样本（n = 23）的时间加权平均（TWA）接触浓度为：己烷36 mg/m³，丙酮50 mg/m³，甲苯10 mg/m³。与BZ样本同时获得的TWA区域浓度（n = 49）为BZ浓度的25%至35%。溶剂排放率（克/任务时间）与总VOC接触浓度相关（R² = 0.45）。BZ样本中VOCs的比例高度相关（r = 0.89至0.95），且与散装产品中的比例相似。在26项任务期间对总VOCs进行的连续接触测量（n = 1238）显示，在开始溶剂喷涂后的1分钟内，BZ的VOC“脉冲”平均为394 mg/m³。工作区域（n = 870）的几何平均风速为5.2米/分钟，与BZ每分钟0.8次换气相关。研究结果表明，使用气溶胶溶剂产品的汽车维修技术人员会间歇性地吸入这些产品中所含的VOCs，且呼吸带中VOCs的比例与散装产品中的比例相似。由于丙酮似乎会加剧正己烷神经毒性作用的严重程度和持续时间，应避免使用同时含有己烷和丙酮的产品。该行业需要进一步评估对VOCs的接触情况，以及关于气溶胶溶剂产品有效替代品的信息。
