Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway.
Institute for Risk Assessment Sciences, Utrecht University, CS Utrecht, The Netherlands.
Ann Work Expo Health. 2022 Aug 7;66(7):895-906. doi: 10.1093/annweh/wxac022.
Workers on offshore petroleum installations are at risk of being exposed to benzene which is carcinogenic to humans. The present study aimed to assess the time trend of full-shift benzene exposure from 2002 to 2018 in order to characterize benzene exposure among laboratory technicians, mechanics, process operators, and industrial cleaners, and to examine the possible determinants of benzene exposure.
A total of 924 measurements of benzene exposure from the Norwegian petroleum offshore industry were included. The median sampling duration was 680 min, ranging from 60 to 940 min. The overall geometric mean (GM) and 95% confidence interval, time trends, and determinants of exposure were estimated using multilevel mixed-effects tobit regression analyses. Time trends were estimated for sampling duration below and above 8 h, both overall and for job groups. The variability of exposure between installation and workers was investigated in a subset of data containing worker identification.
The overall GM of benzene exposure was 0.004 ppm. When adjusting for job group, design of process area, season, wind speed, and sampling duration, industrial cleaners had the highest exposure (GM = 0.012). Laboratory technicians, mechanics, and process operators had a GM exposure of 0.004, 0.003, and 0.004 ppm, respectively. Overall, the measured benzene exposure increased by 7.6% per year from 2002 to 2018. Mechanics had an annual increase of 8.6% and laboratory technicians had an annual decrease of 12.6% when including all measurements. When including only measurements above 8 h, mechanics had an increase of 16.8%. No statistically significant time trend was found for process operators. Open process area, high wind speed, and wintertime were associated with reduced exposure level.
An overall increase in measured exposure was observed from 2002 to 2018. The increase may reflect changes in measurement strategy from mainly measuring on random days to days with expected exposure. However, the time trend varied between job groups and was different for sampling duration above or below 8 h. Industrial cleaners had the highest exposure of the four job groups while no differences in exposure were observed between laboratory technicians, mechanics, and process operators. The design of the process area, job group, wind speed, and season were all significant determinants of benzene exposure.
从事海上石油开采的工人可能会接触到苯，而苯对人类具有致癌性。本研究旨在评估 2002 年至 2018 年期间全班苯暴露的时间趋势，以便对实验室技术员、机械师、工艺操作人员和工业清洁人员的苯暴露情况进行特征描述，并研究苯暴露的可能决定因素。
共纳入了 924 次挪威海上石油工业的苯暴露测量值。中位采样持续时间为 680 分钟，范围为 60 至 940 分钟。使用多水平混合效应 Tobit 回归分析来估计总体几何平均值（GM）和 95%置信区间、时间趋势和暴露决定因素。按采样持续时间 8 小时以下和 8 小时以上，分别对全班和不同工种进行时间趋势估计。在包含工人标识的部分数据中，研究了安装点和工人之间暴露的变异性。
苯暴露的总体 GM 为 0.004ppm。当按工种、工艺区域设计、季节、风速和采样持续时间调整后，工业清洁人员的暴露最高（GM=0.012）。实验室技术员、机械师和工艺操作人员的 GM 暴露值分别为 0.004、0.003 和 0.004ppm。总体而言，2002 年至 2018 年，苯暴露量每年增加 7.6%。包括所有测量值时，机械师的年增长率为 8.6%，实验室技术员的年增长率为-12.6%。当仅包括 8 小时以上的测量值时，机械师的增长率上升至 16.8%。未发现工艺操作人员的暴露量存在统计学显著的时间趋势。开阔的工艺区域、高风速和冬季与暴露水平降低有关。
2002 年至 2018 年，测量的暴露量总体呈上升趋势。这种增加可能反映了测量策略的变化，从主要在随机日测量转变为在预计有暴露的日子测量。然而，时间趋势在工种之间存在差异，并且在采样持续时间 8 小时以上和以下也有所不同。四个工种中，工业清洁人员的暴露量最高，而实验室技术员、机械师和工艺操作人员之间的暴露量没有差异。工艺区域设计、工种、风速和季节都是苯暴露的重要决定因素。
