Department of Occupational and Environmental Medicine, Örebro University Hospital, Örebro, Sweden.
J Occup Environ Hyg. 2012;9(2):110-9. doi: 10.1080/15459624.2011.645397.
Exposure assessment of quartz in Swedish iron foundries was performed based on historical and current measurement data. To evaluate the exposure-response relationship between quartz exposure and lung cancer, we modeled quartz exposure from our database of measurements using determinants job title, time period, and company. Based on these modeled exposure data, we conducted a nested case-control evaluation. In our database, the overall individual, daily time-weighted average (TWA) quartz concentrations of current and historical data varied between 0.0018 and 4.9 mg/m(3), averaging 0.083 mg/m(3). Job titles with mean TWAs for the whole study period exceeding the European Union recommended occupational exposure limit of 0.05 mg/m(3) were fettlers (0.087 mg/m(3)), furnace and ladle repair (0.42 mg/m(3)), and maintenance (0.054 mg/m(3)) workers. The mixed model analysis demonstrated significant determinants on the job level for furnace and ladle repair (β = 4.06; 95% confidence interval [CI] 2.78-5.93). For all jobs, significantly higher exposure levels occurred only during the first time period, 1968-1979 (β = 2.08; 95% CI 1.75-2.47), and a decreasing but not significant trend was noted for the three following 10-year time periods up to 2006 (β = 1.0, 0.96 and 1, respectively). Two iron foundries had significantly higher quartz concentration levels than the others (β = 1.31; 95% CI 1.00-1.71 and β = 1.63; 95% CI 1.00-2.65, respectively). The individual cumulative quartz exposure measures were categorized in low, medium, and high exposure (0.5-<1, 1-1.9 and ≥ 2 mg/m(3)*years, respectively). In the nested case-control analysis, we found the highest odds ratios of lung cancer (OR 1.17; 95% CI 0.53-2.55) for the medium exposure group. No dose-response trend or significantly increased risk was determined for our high exposed group (≥2 mg/m(3)), representing 40 years of exposure at >0.05 mg/m(3) of quartz. To conclude, certain foundry workers are still exposed to high levels of quartz, but an increased risk of lung cancer caused by quartz exposure in these Swedish iron foundries could not be confirmed at our exposure levels.
基于历史和当前的测量数据，对瑞典铸造厂的石英暴露进行了评估。为了评估石英暴露与肺癌之间的暴露-反应关系，我们使用职业头衔、时间和公司等决定因素来模拟数据库中的石英暴露情况。基于这些模型化的暴露数据，我们进行了嵌套病例对照评估。在我们的数据库中，当前和历史数据的个人、每日时间加权平均（TWA）石英浓度的总体平均值在 0.0018 至 4.9 毫克/立方米之间，平均为 0.083 毫克/立方米。整个研究期间平均 TWA 超过欧盟推荐的职业暴露限值 0.05 毫克/立方米的职业头衔为精整工（0.087 毫克/立方米）、熔炉和浇包修理工（0.42 毫克/立方米）和维修工人（0.054 毫克/立方米）。混合模型分析表明，熔炉和浇包修理工的工作水平存在显著的决定因素（β=4.06；95%置信区间[CI]为 2.78-5.93）。对于所有工作，仅在第一个时间段（1968-1979 年）出现显著更高的暴露水平（β=2.08；95%CI 为 1.75-2.47），并且在随后的三个 10 年时间期间（β=1.0、0.96 和 1，分别），暴露水平呈下降趋势但不显著。两家铸造厂的石英浓度水平明显高于其他铸造厂（β=1.31；95%CI 为 1.00-1.71 和 β=1.63；95%CI 为 1.00-2.65，分别）。个体累积石英暴露量被分为低、中、高暴露（分别为 0.5-<1、1-1.9 和≥2 毫克/立方米*年）。在嵌套病例对照分析中，我们发现中暴露组肺癌的最高比值比（OR 1.17；95%CI 0.53-2.55）。对于高暴露组（≥2 毫克/立方米），我们没有确定剂量反应趋势或明显增加的风险，该组暴露于超过 0.05 毫克/立方米的石英长达 40 年。总之，某些铸造厂工人仍暴露于高水平的石英中，但在瑞典这些铸造厂中，由于石英暴露而导致肺癌的风险增加不能在我们的暴露水平下得到证实。
