Schenker M B, Samuels S J, Kado N Y, Hammond S K, Smith T J, Woskie S R
Division of Occupational and Environmental Medicine, University of California, Davis 95616.
Res Rep Health Eff Inst. 1990 Oct(33):1-51; discussion 53-64.
Diesel exhaust is a known mutagen and a potential human carcinogen. Recent epidemiological studies have demonstrated a small increase in the risk of lung cancer from diesel exhaust exposure. However, many epidemiological studies have used crude estimates of exposure, and even accurate measures of exposure may not be accurate estimates of the internal dose received. Measurement of diesel exhaust exposure also has been limited by the absence of a standard marker. This study was undertaken to evaluate the usefulness of urinary mutagenicity as a biological marker of diesel exhaust exposure in the workplace. We measured the exposure of individual railroad workers to diesel exhaust by using personal air samples taken over two consecutive work shifts. Nicotine in the samples was measured to adjust the respirable particle concentrations for active and passive cigarette smoking. Urine samples were collected at the end of the study work shifts and were analyzed for markers of cigarette smoking (nicotine, cotinine) and for mutagenicity, using a sensitive microsuspension assay (micro preincubation assay; Salmonella strain TA98 with or without S9 enzyme). The number of cigarettes smoked on the study shift was recorded, and subjects completed a questionnaire at the end of the second day on personal habits and exposures at home and work. Multiple regression analyses were used to analyze independent determinants of urinary mutagenicity, including a generalized least-squares analysis that divided residual variation into between- and within-person components. Eighty-seven subjects completed 151 two-day protocols; an additional four subjects provided usable data for a single day (n = 306 samples). Respirable particle concentration was not a good marker of diesel exhaust exposure when contamination by environmental tobacco smoke existed in the work location, but respirable particle concentration that was adjusted for environmental tobacco smoke correlated with a priori assessments of diesel exhaust exposure by job grouping. Phenanthrene concentration, as a potential marker, was measured in a subset of personal samples, and correlated with known diesel exhaust exposure by job grouping. A constant ratio of phenanthrene to respirable particles in area samples from diesel exhaust-exposed work locations suggested that phenanthrene is promising as a marker for diesel exhaust. Mutagenic activity was also measured from extracts of respirable particles in a few personal filter samples, and this technique may be useful for further investigation in epidemiological studies.(ABSTRACT TRUNCATED AT 400 WORDS)
柴油废气是一种已知的诱变剂和潜在的人类致癌物。最近的流行病学研究表明，接触柴油废气会使患肺癌的风险略有增加。然而，许多流行病学研究使用的是粗略的接触估计值，即使是准确的接触测量值也可能无法准确估计所接受的内部剂量。柴油废气接触的测量还受到缺乏标准标志物的限制。本研究旨在评估尿致突变性作为工作场所柴油废气接触生物标志物的实用性。我们通过在连续两个工作班次采集个人空气样本，测量了个体铁路工人接触柴油废气的情况。测量样本中的尼古丁，以调整主动和被动吸烟对可吸入颗粒物浓度的影响。在研究工作班次结束时收集尿液样本，并使用灵敏的微悬浮试验（微预孵化试验；带有或不带有S9酶的沙门氏菌TA98菌株）分析吸烟标志物（尼古丁、可替宁）和致突变性。记录研究班次所吸香烟的数量，受试者在第二天结束时填写一份关于个人习惯以及在家和工作场所接触情况的问卷。使用多元回归分析来分析尿致突变性的独立决定因素，包括将残差变异分为个体间和个体内成分的广义最小二乘法分析。87名受试者完成了151个为期两天的方案；另外4名受试者提供了一天的可用数据（n = 306个样本）。当工作场所存在环境烟草烟雾污染时，可吸入颗粒物浓度不是柴油废气接触的良好标志物，但针对环境烟草烟雾进行调整后的可吸入颗粒物浓度与按工作分组对柴油废气接触的先验评估相关。在一部分个人样本中测量了菲的浓度，作为一种潜在标志物，它与按工作分组已知的柴油废气接触情况相关。来自柴油废气暴露工作场所的区域样本中，菲与可吸入颗粒物的比例恒定，这表明菲有望作为柴油废气的标志物。还在一些个人过滤样本中测量了可吸入颗粒物提取物的致突变活性，该技术可能有助于在流行病学研究中进一步开展调查。（摘要截选至400字）
