Defence R&D Canada-Suffield, Alberta, Canada.
J Occup Environ Hyg. 2011 Feb;8(2):113-22. doi: 10.1080/15459624.2011.547454.
In 2001, letters filled with a powder containing anthrax (Bacillus anthracis) spores were delivered by mail to a number of governmental and media locations within the United States. In response, the U.S. Centers for Disease Control and Prevention (CDC) provided guidelines for office personnel who might encounter a letter containing suspicious powder. These guidelines were developed during the crisis and in the absence of experimental data from laboratory or field investigations. An obvious need thus exists for quantitative and scientific verification for validation of these guidelines. This study attempts to address this need, adapting earlier work that used a multiple small office test site to create a model system in an open office test site in a vacated office building in which Bacillus atrophaeus spores (as a simulant for B. anthracis spores) were released by opening a letter. Using SF(6) as a tracer gas, smoke tubes (containing stannic chloride) to visualize airflow, culturable aerosol sampling, and aerosol spectrometry we were able to characterize airflow and unmitigated spore aerosol dissemination within the office test site. Subsequently, two scripted test scenarios were used to reproduce selected portions of the existing CDC response guidelines and a modified version where the contaminated letter opener warned co-workers to evacuate then waited 5 min before doing so himself. By not leaving together with other co-workers, the risk of the letter opener cross-contaminating others was eliminated. The total potential spore aerosol exposure of the letter opener was not affected by remaining still and waiting 5 min to allow co-workers to escape first before leaving the office. Closing office doors and quickly deactivating the heating, ventilation, and air conditioning system significantly reduced spore aerosol concentrations outside the main open office in which they had been released.
2001 年，装有炭疽杆菌（Bacillus anthracis）孢子粉末的信件通过邮件寄往美国的一些政府和媒体机构。作为回应，美国疾病控制与预防中心（CDC）为可能遇到可疑粉末信件的办公室人员提供了指导方针。这些指南是在危机期间制定的，当时缺乏来自实验室或现场调查的实验数据。因此，显然需要对这些指南进行定量和科学验证，以验证其有效性。本研究试图满足这一需求，利用早期的工作，使用多个小型办公室测试点，在一个废弃办公大楼的开放式办公室测试点创建了一个模型系统，在该系统中，通过打开一封信，释放萎缩芽孢杆菌（作为炭疽杆菌孢子的模拟物）孢子。使用 SF（6）作为示踪气体，烟雾管（含有氯化亚锡）可视化气流，可培养气溶胶采样和气溶胶光谱法，我们能够描述办公室测试点内的气流和未减轻的孢子气溶胶传播。随后，使用两个脚本测试场景来重现现有的 CDC 应对指南的部分内容，以及一个修改后的版本，其中受污染的拆信刀警告同事们撤离，然后在离开前等待 5 分钟。拆信刀没有与其他同事一起离开，从而消除了拆信刀交叉污染他人的风险。在离开办公室之前，等待 5 分钟让同事先逃跑，拆信刀的总潜在孢子气溶胶暴露量不会受到影响。关闭办公室门并迅速停用加热、通风和空调系统，显著降低了它们在其中释放的主要开放式办公室外的孢子气溶胶浓度。
