Symanski Elaine, Greeson Nicole M H
University of Texas School of Public Health, 1200 Herman Pressler Dr., Houston, TX 77030, USA.
AIHA J (Fairfax, Va). 2002 Jul-Aug;63(4):390-401. doi: 10.1080/15428110208984727.
Although intra- and interindividual sources of variation in airborne exposures have been extensively studied, similar investigations examining variability in biological measures of exposure have been limited. Following a review of the world's published literature, biological monitoring data were abstracted from 53 studies that examined workers' exposures to metals, solvents, polycyclic aromatic hydrocarbons, and pesticides. Approximately 40% of the studies also reported personal sampling results, which were compiled as well. In this study, the authors evaluated the intra- and interindividual sources of variation in biological measures of exposure collected on workers employed at the same plant. In 60% of the data sets, there was more variation among workers than variation from day to day. Approximately one-fourth of the data were homogeneous with small differences among workers' mean exposure levels. However, an almost equal number of data sets exhibited moderate to extreme levels of heterogeneity in exposures among workers at the same facility. In addition, the relative magnitude of the intra- to interindividual source of variation was larger for biomarkers with short compared to long half-lives, which suggests that biomarkers with half-lives of 7 days or longer exhibit physiologic dampening of fluctuations in external levels of the workplace contaminant and thereby may offer advantages when compared to short-lived biomarkers or exposures assessed by air monitoring. The use of biological indices of exposure, however, places an additional burden on the strategy used to evaluate exposures, because data may be serially correlated as evidenced in this study, which could result in biased estimates of the variance components if autocorrelation is undetected or ignored in the statistical analyses.
尽管空气中暴露的个体内和个体间变异来源已得到广泛研究，但对暴露生物测量变异的类似调查却很有限。在对全球已发表文献进行综述后，从53项研究中提取了生物监测数据，这些研究考察了工人对金属、溶剂、多环芳烃和农药的暴露情况。约40%的研究还报告了个人采样结果，这些结果也进行了汇总。在本研究中，作者评估了同一工厂工人所收集的暴露生物测量中的个体内和个体间变异来源。在60%的数据集中，工人之间的变异大于每日之间的变异。约四分之一的数据具有同质性，工人平均暴露水平差异较小。然而，几乎同样数量的数据集显示同一工厂工人的暴露存在中度到极端水平的异质性。此外，与半衰期长的生物标志物相比，半衰期短的生物标志物个体内与个体间变异来源的相对大小更大，这表明半衰期为7天或更长的生物标志物对工作场所污染物外部水平波动具有生理缓冲作用，因此与短寿命生物标志物或通过空气监测评估的暴露相比可能具有优势。然而，使用暴露生物指标给评估暴露的策略带来了额外负担，因为正如本研究所示数据可能存在序列相关性，如果在统计分析中未检测到或忽略自相关性，可能会导致方差成分的估计有偏差。
