CPWR - The Center for Construction Research and Training, Silver Spring, Maryland.
Environmental Profiles, Inc, Columbia, Maryland.
J Occup Environ Hyg. 2021 Jun;18(6):237-249. doi: 10.1080/15459624.2021.1910277. Epub 2021 May 14.
The study assessed potential to exceed occupational exposure limits while spraying paint with and without a silver nanoparticle biocidal additive. A tradesperson performed the tasks in a sealed chamber with filtered air supply. Integrated air sampling entailed transmission electron microscopy with energy dispersive X-ray analysis, direct-reading of particle number concentrations, and determination of silver mass concentration by NIOSH Method 7300. Silver nanoparticles were primarily embedded in paint spray droplets but also observed as isolated particles. Using an α-level of 0.05, median nanoparticle number concentrations did not differ significantly when spraying conventional vs. biocidal paint, although statistically significant differences were observed at specific particle size ranges <100 nm. The geometric mean concentration of total silver while spraying biocidal paint (n = 6) was 2.1 µg/m (95% CI: 1.5-2.8 µg/m), and no respirable silver was detected (<0.50 µg/m). The results address a lack of silver nanoparticle exposure data in construction and demonstrate the feasibility of a practical sampling approach. Given similar conditions, the measurements suggest a low probability of exceeding a proposed silver nanoparticle exposure limit of 0.9 µg/m as an airborne 8-hr time-weighted average respirable mass concentration. A full workday of exposure to respirable silver at the highest possible level in this study (<0.50 µg/m) would not exceed the exposure limit, although limitations in comparing short task-based exposures to an 8-hr exposure limit must be noted. There was airflow in the study chamber, whereas exposure levels could increase over time in work environments lacking adequate ventilation. Potential to exceed the exposure limit hinged upon the respirable fraction of the paint mist, which could vary by material and application method. Additional research would improve understanding of silver nanoparticle exposure risks among construction trades, and biological responses to these exposures. Given the potential for exposure variability on construction jobsites, safety and health professionals should be cognizant of methods to assess and control silver nanoparticle exposures.
本研究评估了在喷涂油漆时（添加和不添加含银纳米颗粒的杀菌添加剂）是否有可能超过职业接触限值。一名技工在密封的带过滤空气供应的室内进行了这些任务。综合空气采样包括使用透射电子显微镜和能量色散 X 射线分析、直接读取粒子数浓度以及通过 NIOSH 方法 7300 测定银的质量浓度。银纳米颗粒主要嵌入在油漆喷雾液滴中，但也观察到孤立的颗粒。使用 0.05 的α水平，当喷涂常规油漆和杀菌油漆时，纳米颗粒数浓度的中位数没有显著差异，尽管在特定的粒径范围 <100nm 时观察到了统计学上的显著差异。在喷涂杀菌油漆时（n=6）总银的几何平均值浓度为 2.1μg/m（95%CI：1.5-2.8μg/m），未检测到可吸入银（<0.50μg/m）。研究结果解决了建筑行业缺乏银纳米颗粒暴露数据的问题，并证明了实用采样方法的可行性。在类似的条件下，测量结果表明，在作为 8 小时时间加权平均可吸入质量浓度的空气传播中，超过拟议的银纳米颗粒暴露限值 0.9μg/m 的可能性较低。在本研究中（<0.50μg/m），暴露在最高可能水平的可吸入银下一整天都不会超过暴露限值，尽管必须注意将基于短时间任务的暴露与 8 小时暴露限值进行比较的局限性。研究室中有气流，而在缺乏足够通风的工作环境中，暴露水平可能会随时间增加。超过暴露限值的可能性取决于油漆雾的可吸入部分，这可能因材料和应用方法而异。进一步的研究将提高对建筑行业中银纳米颗粒暴露风险以及对这些暴露的生物反应的理解。考虑到建筑工地暴露的可变性，安全和健康专业人员应意识到评估和控制银纳米颗粒暴露的方法。
