Workplace Aerosol Sampling at Realistic Low Windspeeds

描述：气溶胶采样器仍然很重要，因为它们在评估（并因此控制）工人接触空气中颗粒的作用。呼吸系统疾病，包括哮喘和慢性阻塞性肺病，仍然是NORA的主要优先领域。拟议的研究是在RO1-OH 02984-02（1994-1998）、5个RO1-OH 03687-03（1998-2002）和5个RO1 OH 02984-06（1999-2003）下开展的一系列工作的延续，补充了其他资源支持的实地研究。这项新计划将包括进一步的实验室研究，以发展有意义的气溶胶采样方法，在实际的低风速条件下（0.05至0.5米/秒），而不是在以前的研究中。具体目标是：a)开发一种基于实验室的新型实验系统，通过该系统评估大多数工作场所低风速下的气溶胶采样器；(b)用它来评估基于级联撞击器的气溶胶采样系统，该系统将提供有关工人气溶胶暴露中粒径分布的信息；(c)界定人体在极低风速下的吸入效率（使用人体模型），并考虑到受试者的呼吸模式和体温的影响；(d)描述在这种条件下使用的一系列候选个人可吸入气溶胶取样器的性能；(e)使用这些性能信息来解释不同采样器在实际实验室环境中使用时的质量偏差（并将结论与实地研究中观察到的结果联系起来）。早期的工作对制定职业暴露标准和建立相关的暴露评估方法产生了影响。然而，仍然存在相当大的知识差距。我们仍然无法解释具体的个人采样器在多大程度上反映了实际工人的暴露，也无法解释使用各种推荐采样器的工作场所暴露评估之间的差异。新的研究将填补这些空白，并将职业气溶胶暴露评估置于更加坚实的基础上。

DESCRIPTION: Aerosol samplers remain important through their role in the assessment (and hence control) of workers' exposures to airborne particles. Respiratory ill-health, including asthma and chronic obstructive pulmonary disease, remain major NORA priority areas. The proposed research is a continuation of a body of work carried out under RO1-OH 02984-02 (1994-1998), and then 5 RO1-OH 03687-03 (1998-2002) and 5 RO1 OH 02984-06 (1999-2003), complementing field studies supported from other resources. This new project will contain further laboratory research to develop meaningful aerosol sampling methodology under realistically low windspeed conditions not covered by previous research (0.05 to 0.5 m/s). The specific aims are to: a) develop a novel laboratory-based experimental system by which to evaluate aerosol samplers at the low windspeeds found in most workplaces; (b) use it to evaluate cascade impactor- based aerosol sampling systems that will provide information about the particle size distributions in workers' aerosol exposures; (c) define the efficiency of human inhalation (using a mannequin) at very low windspeed, allowing for the effects of the breathing patterns of the subject and body heat; (d) characterize the performances of a range of candidate personal inhalable aerosol samplers when used under such conditions; and (e) use such performance information to explain the mass biases between different samplers when they are used in realistic laboratory environments (and to relate the conclusions to what is observed in field studies). Earlier work has been influential in the setting of occupational exposure standards and in establishing relevant exposure assessment methods. Yet there remain considerable knowledge gaps. We are still unable to explain the extent to which specific personal samplers reflect actual worker exposure, or to explain differences between workplace exposure assessments using various recommended samplers. The new research will fill these gaps and place occupational aerosol exposure assessment on a still firmer footing.