Peters Susan, Kromhout Hans, Portengen Lützen, Olsson Ann, Kendzia Benjamin, Vincent Raymond, Savary Barbara, Lavoué Jérôme, Cavallo Domenico, Cattaneo Andrea, Mirabelli Dario, Plato Nils, Fevotte Joelle, Pesch Beate, Brüning Thomas, Straif Kurt, Vermeulen Roel
Environmental Epidemiology Division, Institute for Risk Assessment Sciences, Utrecht University, 3584 CK Utrecht, The Netherlands.
Ann Occup Hyg. 2013 Jan;57(1):98-106. doi: 10.1093/annhyg/mes045. Epub 2012 Jul 17.
We describe the elaboration and sensitivity analyses of a quantitative job-exposure matrix (SYN-JEM) for respirable crystalline silica (RCS). The aim was to gain insight into the robustness of the SYN-JEM RCS estimates based on critical decisions taken in the elaboration process.
SYN-JEM for RCS exposure consists of three axes (job, region, and year) based on estimates derived from a previously developed statistical model. To elaborate SYN-JEM, several decisions were taken: i.e. the application of (i) a single time trend; (ii) region-specific adjustments in RCS exposure; and (iii) a prior job-specific exposure level (by the semi-quantitative DOM-JEM), with an override of 0 mg/m(3) for jobs a priori defined as non-exposed. Furthermore, we assumed that exposure levels reached a ceiling in 1960 and remained constant prior to this date. We applied SYN-JEM to the occupational histories of subjects from a large international pooled community-based case-control study. Cumulative exposure levels derived with SYN-JEM were compared with those from alternative models, described by Pearson correlation ((Rp)) and differences in unit of exposure (mg/m(3)-year). Alternative models concerned changes in application of job- and region-specific estimates and exposure ceiling, and omitting the a priori exposure ranking.
Cumulative exposure levels for the study subjects ranged from 0.01 to 60 mg/m(3)-years, with a median of 1.76 mg/m(3)-years. Exposure levels derived from SYN-JEM and alternative models were overall highly correlated (R(p) > 0.90), although somewhat lower when omitting the region estimate ((Rp) = 0.80) or not taking into account the assigned semi-quantitative exposure level (R(p) = 0.65). Modification of the time trend (i.e. exposure ceiling at 1950 or 1970, or assuming a decline before 1960) caused the largest changes in absolute exposure levels (26-33% difference), but without changing the relative ranking ((Rp) = 0.99).
Exposure estimates derived from SYN-JEM appeared to be plausible compared with (historical) levels described in the literature. Decisions taken in the development of SYN-JEM did not critically change the cumulative exposure levels. The influence of region-specific estimates needs to be explored in future risk analyses.
我们描述了一种用于可吸入结晶二氧化硅（RCS）的定量工作暴露矩阵（SYN-JEM）的制定及敏感性分析。目的是基于制定过程中做出的关键决策，深入了解SYN-JEM对RCS暴露估计的稳健性。
基于先前开发的统计模型得出的估计值，RCS暴露的SYN-JEM由三个轴（工作、地区和年份）组成。为了制定SYN-JEM，做出了几个决策：即应用（i）单一时间趋势；（ii）RCS暴露的地区特定调整；以及（iii）先前特定工作的暴露水平（通过半定量DOM-JEM），对于先验定义为未暴露的工作，其暴露水平上限为0 mg/m³。此外，我们假设暴露水平在1960年达到上限，并在此日期之前保持不变。我们将SYN-JEM应用于一项大型国际基于社区的汇总病例对照研究中受试者的职业史。将SYN-JEM得出的累积暴露水平与替代模型得出的水平进行比较，通过Pearson相关性（Rp）和暴露单位（mg/m³-年）的差异来描述。替代模型涉及特定工作和地区估计以及暴露上限应用的变化，以及省略先验暴露排名。
研究对象的累积暴露水平范围为0.01至60 mg/m³-年，中位数为1.76 mg/m³-年。SYN-JEM和替代模型得出的暴露水平总体高度相关（Rp>0.90），尽管在省略地区估计（Rp = 0.80）或不考虑指定的半定量暴露水平时（Rp = 0.65）相关性略低。时间趋势的改变（即1950年或1970年的暴露上限，或假设1960年之前暴露水平下降）导致绝对暴露水平的最大变化（差异为26 - 33%），但不改变相对排名（Rp = 0.99）。
与文献中描述的（历史）水平相比，SYN-JEM得出的暴露估计似乎是合理的。在SYN-JEM开发过程中做出的决策并没有严重改变累积暴露水平。在未来的风险分析中需要探索地区特定估计的影响。
