Dahm Matthew M, Evans Douglas E, Bertke Stephen, Grinshpun Sergey A
Division of Surveillance, Hazard Evaluations, and Field Studies, National Institute for Occupational Safety and Health, Cincinnati, OH 45226, USA.
Division of Applied Research and Technology, National Institute for Occupational Safety and Health, 1090 Tusculum Ave, Cincinnati, OH 45226, USA.
Aerosol Sci Technol. 2019;53(8):958-970. doi: 10.1080/02786826.2019.1618437. Epub 2019 May 30.
A growing number of carbon nanotubes and nanofibers (CNT/F) exposure and epidemiologic studies have utilized 25-mm and 37-mm open-faced cassettes (OFC) to assess the inhalable aerosol fraction. It has been previously established that the 37-mm OFC under-samples particles greater than 20 μm in diameter, but the size-selective characteristics of the 25-mm OFC have not yet been fully evaluated. This article describes an experimental study conducted to determine if the 25- and 37-mm OFCs performed with relative equivalence to a reference inhalable aerosol sampler when challenged with CNT/F particles. Side-by-side paired samples were collected within a small Venturi chamber using a 25-mm styrene OFC, 37-mm styrene OFC, 25-mm aluminum OFC, and Button Inhalable Aerosol Sampler. Three types of CNT/F materials and an Arizona road dust were used as challenge aerosols for the various sampler configurations. Repeated experiments were conducted for each sampler configuration and material. The OFC samplers operated at flow rates of 2 and 5 liters per minute. Results showed that the 25-mm OFC performed comparably to the Button Sampler when challenged with CNT/F aerosols, which was demonstrated in five of the six experimental scenarios with an average error of 20%. Overall, the results of this study indicate that the sampling efficiency of the 25- and 37-mm OFCs adequately followed the ISO/ACGIH/CEN inhalable sampling convention when challenged with CNT/F aerosols. Past exposure and epidemiologic studies that used these OFC samplers can directly compare their results to studies that have used other validated inhalable aerosol samplers.
越来越多的碳纳米管和纳米纤维（CNT/F）暴露及流行病学研究使用25毫米和37毫米开口式采样盒（OFC）来评估可吸入气溶胶部分。此前已经确定，37毫米的OFC对直径大于20微米的颗粒采样不足，但25毫米OFC的尺寸选择特性尚未得到充分评估。本文描述了一项实验研究，旨在确定当受到CNT/F颗粒挑战时，25毫米和37毫米的OFC与参考可吸入气溶胶采样器的性能是否相对等效。在一个小型文丘里室内，使用25毫米苯乙烯OFC、37毫米苯乙烯OFC、25毫米铝制OFC和纽扣式可吸入气溶胶采样器并排采集配对样本。三种类型的CNT/F材料和一种亚利桑那道路灰尘被用作各种采样器配置的挑战气溶胶。对每种采样器配置和材料进行了重复实验。OFC采样器的流速为每分钟2升和5升。结果表明，当受到CNT/F气溶胶挑战时，25毫米的OFC与纽扣式采样器的性能相当，在六个实验场景中的五个场景中得到了证明，平均误差为20%。总体而言，本研究结果表明，当受到CNT/F气溶胶挑战时，25毫米和37毫米OFC的采样效率充分遵循了ISO/ACGIH/CEN可吸入采样惯例。过去使用这些OFC采样器的暴露和流行病学研究可以将其结果与使用其他经过验证的可吸入气溶胶采样器的研究直接进行比较。
