Institute for Work and Health (IST), University of Lausanne and Geneva, Route de la Corniche 2, 1066 Epalinges, Switzerland.
Institute of Lung Biology and Disease (iLBD), Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764 Neuherberg, Germany.
Ann Work Expo Health. 2017 Nov 10;61(9):1132-1144. doi: 10.1093/annweh/wxx081.
We tested the nanomaterial release from composites during two different mechanical treatment processes, automated drilling and manual sawing. Polyurethane (PU) polymer discs (1-cm thickness and 11-cm diameter) were created using different nanomaterial fillers: multiwall carbon nanotubes (MWCNT), carbon black (CB), silicon dioxide (SiO2), and an unfilled PU control. Drilling generated far more submicron range particles than sawing. In the drilling experiments, none of the tested nanofillers showed a significant influence on particle number concentrations or sizes, except for the PU/MWCNT samples, from which larger particles were released than from control samples. Higher drilling speed and larger drill bit size were associated with higher particle counts. Differences between composites were observed during sawing: PU/CB released higher number concentrations of micro-sized particles compared to reference samples. When sawing PU/SiO2 more nanoparticle agglomerates were observed. Furthermore, polymer fumes were released during sawing experiments, which was attributed to the process heat. For both drilling and sawing, the majority of the aerosolized particles were polymer matrix materials containing nanofillers (or protruding from their surface), as evidenced by electron microscopic analysis. Results suggest that: (i) processes associated with higher energy inputs are more likely to result in higher particle release in terms of number concentration; (ii) nanofillers may alter release processes; and (iii) other types of released particles, in particular polymer fumes from high-temperature processes, must also be considered in occupational exposure and risk assessments.
我们测试了复合材料在两种不同机械处理过程（自动钻孔和手动锯切）中纳米材料的释放情况。使用不同的纳米材料填充物（多壁碳纳米管 (MWCNT)、炭黑 (CB)、二氧化硅 (SiO2) 和未填充的 PU 对照）制造了聚氨酯 (PU) 聚合物盘（1 厘米厚和 11 厘米直径）。钻孔产生的亚微米范围内的颗粒比锯切多得多。在钻孔实验中，除了 PU/MWCNT 样品外，没有一种测试的纳米填料对颗粒数浓度或尺寸有显著影响，从这些样品中释放出的颗粒比对照样品大。更高的钻孔速度和更大的钻头尺寸与更高的颗粒计数有关。在锯切过程中观察到复合材料之间的差异：与参考样品相比，PU/CB 释放出更高数浓度的微尺寸颗粒。在锯切 PU/SiO2 时，观察到更多的纳米颗粒团聚体。此外，在锯切实验中释放出聚合物烟雾，这归因于过程热量。对于钻孔和锯切，大部分气溶胶化颗粒是含有纳米填料的聚合物基质材料（或从其表面突出），这可以通过电子显微镜分析证明。结果表明：(i) 与更高能量输入相关的过程更有可能导致更高的数浓度颗粒释放；(ii) 纳米填料可能改变释放过程；(iii) 其他类型的释放颗粒，特别是高温过程中的聚合物烟雾，也必须在职业暴露和风险评估中考虑。
