A New Air Sampling System for Long-Term Sampling

描述：在职业卫生中，一个持续的挑战是准确估计工人长期暴露于工作场所和周围社区中大量空气传播的化学物质。因此，为了确保完成准确的接触评估，必须发展能够对工作场所的污染物进行更有效采样的新方法。多年来，真空罐一直用于收集周围空气中的气体和蒸气样本。随着一种新的流量控制装置的发展，人们对使用真空罐进行个人呼吸区采样作为吸附剂采样器的替代方法的兴趣增加了。毛细管流量控制器最近被设计为提供一个非常低的流速，允许样品收集在一段时间内使用一个小的便携式罐。最初的研究集中在毛细管罐的开发和评估其收集代表性样品的能力。最近的研究表明，代表性的样品可以在极低的流量（0.05至1.0 ImL/min）下在小型（300 mL）真空罐中有效收集。本建议的具体目的是：1。1 .测试毛细管罐在各种空气采样环境中的适用性，包括室内空气和工厂环境；2 .检查不同暴露评估情景之间的相关性，例如收集多个8小时样本与单个40小时样本；通过广泛的计算机模拟量化与流量递减相关的偏差，并通过与测量数据的比较验证数学模型。总之，我们希望证明这种新的创新采样系统以经济有效的方式收集准确和有代表性的空气样本，其总体不确定度在可接受的指导方针范围内。经过验证的毛细管罐设备将使工业卫生学家能够延长个人采样时间，超出目前获得的时间，并同时对更广泛的化学品进行采样。

DESCRIPTION: A continuing challenge in occupational hygiene is that of accurately estimating a worker's long-term exposure to the multitude of airborne chemicals found in the workplace and surrounding community. Hence, the development of new methods that will permit more effective sampling of contaminants in the workplace is essential to ensure that accurate exposure assessments are completed. Evacuated canisters have been used for many years to collect ambient air samples for gases and vapors. With the development of a new flow control device, interest in using evacuated canisters for personal breathing zone sampling as an alternative to sorbent samplers has increased. A capillary flow controller was recently designed to provide a very low flow rate, permitting a sample to be collected over an extended period of time with the use of a small portable canister. Initial research focused on the development of the capillary canister and the evaluation of its ability to collect a representative sample. Recent studies indicate that representative samples can be effectively collected at extremely low flow rates ranging from 0.05 to 1.0 ImL/min in small (300 mL) evacuated canisters. The specific aims of this proposal are to: 1. Test the applicability of the capillary-canister in a variety of air sampling environments, including indoor air and factory environments, 2. Examine the correlation between different exposure assessment scenarios, such as the collection of multiple 8-hour samples versus a single 40-hour sample, 3. Quantify the bias associated with the diminishing flow rate through extensive computer simulations and validate the mathematical model through comparison with measured data. In summary, we hope to demonstrate that this new innovative sampling system collects accurate and representative air samples in a cost effective manner, with verified overall uncertainties that are well within acceptable guidelines. A validated capillary-canister device will equip industrial hygienists with the ability to extend personal sampling times beyond what is currently obtained and to sample a broader range of chemicals simultaneously.