Workplace Aerosol Sampling at Realistic Low Windspeeds

描述：气溶胶采样器在评估(并因此控制)工人暴露在空气中颗粒物的过程中发挥着重要作用。呼吸道疾病，包括哮喘和慢性阻塞性肺病，仍然是NARA的主要优先领域。拟议的研究是在RO1-OH 02984-02(1994年至1998年)、5 RO1-OH 03687-03(1998年-2002年)和5 RO1-OH 02984-06(1999年-2003年)下开展的一系列工作的继续，补充了由其他资源支助的实地研究。这个新项目将包含进一步的实验室研究，以开发在先前研究未涵盖的实际低风速条件下(0.05至0.5m/S)有意义的气溶胶采样方法。具体目标是：a)开发一种新的实验室实验系统，用以在大多数工作场所发现的低风速条件下评估气溶胶采样器；(B)利用该系统评估基于梯级冲击器的气溶胶采样器，该系统将提供工人暴露在气溶胶中的颗粒尺寸分布信息；(C)确定人体在极低风速下的吸入效率(使用人体模型)，以考虑受试者的呼吸模式和体温的影响；(D)确定一系列候选个人可吸入气溶胶采样器在这种条件下使用时的性能特征；以及(E)使用这种性能信息来解释不同取样器在实际实验室环境中使用时的质量偏差(并将结论与在实地研究中观察到的结果联系起来)。早期的工作对职业暴露标准的制定和相关暴露评估方法的制定产生了影响。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工人的实际接触情况，也无法解释使用各种推荐采样器进行的工作场所暴露评估之间的差异。这项新研究将填补这些空白，并为职业性气溶胶暴露评估奠定更坚实的基础。

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.