Bakke Berit, Ulvestad Bente, Thomassen Yngvar, Woldbaek Torill, Ellingsen Dag G
1.Department of Chemical and Biological Work Environment, National Institute of Occupational Health, PO Box 8149 Dep, 0033 Oslo, Norway
2.Department of Occupational Medicine and Epidemiology, National Institute of Occupational Health, PO Box 8149 Dep, 0033 Oslo, Norway.
Ann Occup Hyg. 2014 Aug;58(7):818-29. doi: 10.1093/annhyg/meu034. Epub 2014 Jun 5.
Personal air measurements of aerosols and gases among tunnel construction workers were performed as part of a 11-day follow-up study on the relationship between exposure to aerosols and gases and cardiovascular and respiratory effects.
Ninety tunnel construction workers employed at 11 available construction sites participated in the exposure study. The workers were divided into seven job groups according to tasks performed. Exposure measurements were carried out on 2 consecutive working days prior to the day of health examination. Summary statistics were computed using maximum likelihood estimation (MLE), and the procedure NLMIXED and LIFEREG in SAS was used to perform MLE for repeated measures data subject to left censoring and for calculation of within- and between-worker variance components.
The geometric mean (GM) air concentrations for the thoracic mass aerosol sub-fraction, α-quartz, oil mist, organic carbon (OC), and elemental carbon (EC) for all workers were 561, 63, 210, 146, and 35.2 μg m(-3), respectively. Statistical differences of air concentrations between job groups were observed for all contaminants, except for OC, EC, and ammonia (P > 0.05). The shaft drillers, injection workers, and shotcreting operators were exposed to the highest GM levels of thoracic dust (7061, 1087, and 865 μg m(-) (3), respectively). The shaft drillers and the support workers were exposed to the highest GM levels of α-quartz (GM = 844 and 118 μg m(-3), respectively). Overall, the exposure to nitrogen dioxide and ammonia was low (GM = 120 and 251 μg m(-) (3), respectively).
Findings from this study show significant differences between job groups with shaft drilling as the highest exposed job to air concentrations for all measured contaminants. Technical interventions in this job should be implemented to reduce exposure levels. Overall, diesel exhaust air concentrations seem to be lower than previously assessed (as EC).
作为一项为期11天的关于气溶胶和气体暴露与心血管及呼吸系统影响之间关系的随访研究的一部分，对隧道建设工人进行了个人气溶胶和气体测量。
在11个可用建筑工地工作的90名隧道建设工人参与了暴露研究。根据执行的任务，工人被分为7个工作小组。在健康检查当天之前的连续2个工作日进行暴露测量。使用最大似然估计（MLE）计算汇总统计量，并使用SAS中的NLMIXED和LIFEREG程序对受左删失影响的重复测量数据进行MLE，并计算工人内部和工人之间的方差分量。
所有工人的胸部质量气溶胶亚组分、α-石英、油雾、有机碳（OC）和元素碳（EC）的几何平均（GM）空气浓度分别为561、63、210、146和35.2 μg m(-3)。除OC、EC和氨外，所有污染物在工作小组之间的空气浓度均存在统计学差异（P>0.05）。竖井钻探工人、喷射工人和喷射混凝土操作员接触的胸部粉尘GM水平最高（分别为7061、1087和865 μg m(-3)）。竖井钻探工人和支护工人接触的α-石英GM水平最高（GM分别为844和118 μg m(-3)）。总体而言，二氧化氮和氨的暴露水平较低（GM分别为120和251 μg m(-3)）。
本研究结果表明，竖井钻探是所有测量污染物空气浓度暴露最高的工作，各工作小组之间存在显著差异。应在该工作中实施技术干预以降低暴露水平。总体而言，柴油废气空气浓度似乎低于先前评估的水平（以EC计）。
