A Personal Monitor for Space- and Time-Resolved Measurements of Aerosol Exposure

描述（由申请者提供）：拟议项目将开发和演示一种小型便携式气溶胶采样器，该采样器将收集一系列时间和地点分辨的个人接触样本，用于研究环境接触、遗传和健康之间的关系。它还将开发一个台式测定装置，用于对收集的样品进行内毒素比色测定。采样器将采用一系列新颖的微通道收集器，并与位置监测器（GPS）和活动监测器（加速度计）结合使用，将收集一系列时间序列的暴露样本，这些样本将被标记时间和位置，以便研究人员能够充分描述受试者在其环境中旅行时的暴露历史。采样装置将非常小，重量轻，电池供电，即使是10岁的儿童也可以放在背包里携带。这一装置将大大提高在空间和时间上确定接触事件地点的能力，并将提供一个关键工具，用于解决接触与人类健康影响之间关系的不确定性。每个采样单元将包含一个装有微通道收集器阵列的转盘，微通道收集器将以30分钟（或更短）的间隔收集样品。转盘将容纳多达48个采集器，允许在24小时内采集样本。一旦收集完所有样本，转盘将被转移到台式分析单元，该单元将对所有收集的样本进行分析，大大减少了与典型流行病学研究期间收集的大量样本的分析相关的工作量。这种气溶胶取样和检测装置将与太平洋西北国家实验室开发的自动化技术相结合，以生产一个独立的便携式个人接触取样装置和一个台式化验装置。Enertechnix将负责气溶胶采样和微流体组件以及系统集成。PNNL将调整其自动化，电源管理，位置和运动传感技术用于PEM。华盛顿大学（UW）将协助采用FAR Sciences开发的微型比色读出单元实施内毒素测定。将开发原型，并与华盛顿大学合作，将在各种环境中进行现场测试，以证明采样器和台式分析装置的性能。该系统将是第一个提供高效气溶胶到微流体接口的系统，也是第一个在便携式包装中提供自动化、时间和空间分辨采样的系统。 公共卫生相关性：人们越来越认识到，接触细颗粒物和柴油机颗粒物等环境污染物可能引发或加剧哮喘和心血管疾病等疾病，但具体因素的重要性以及疾病与接触之间的关系仍存在很大的不确定性。在美国，哮喘影响1400万至1500万人，其中约480万是儿童;在过去15年中，哮喘在全世界的发病率翻了一番;并且哮喘每年造成1亿人-日的活动受限和5000人死亡，直接健康相关成本总计81亿美元。内毒素是革兰氏阴性菌中普遍存在的一种重要的生物活性环境因子，可引起哮喘症状：支气管收缩、气道炎症和气道高反应性。已知内毒素水平在空间和时间上高度可变，其与哮喘症状和疾病严重程度相关。拟议的项目将开发一种改进的个人接触监测器，可用于对便携式装置中的空气悬浮颗粒中所含内毒素进行空间和时间分辨测量，可用于研究，以更好地了解接触与人类健康影响之间的关系。

DESCRIPTION (provided by applicant): The proposed project will develop and demonstrate a miniaturized, portable aerosol sampler that will collect a series of time- and location-resolved personal exposure samples for conducting research into the relationships among environmental exposure, genetics and health. It will also develop a bench-top assay unit that will perform colorimetric assays for endotoxin on the collected samples. The sampler will employ an array of novel micro-channel collectors, and, when combined with a position-monitor (GPS) and activity monitor (accelerometer), will collect a time-series of exposure samples that will be time- and location- stamped to allow researchers to fully characterize the exposure history of subjects as they travel through their environment. The sampling unit will be extremely small, light-weight and battery operated to allow it to be carried in a back-pack even by a 10-year old child. This device will significantly improve the ability to localize exposure events in space and time and will provide a critical tool for use in resolving uncertainties about the relationships between exposure and human health impacts. Each sampling unit will contain a carousel holding an array of micro-channel collectors which will collect samples at 30 minute (or shorter) intervals. The carousel will hold up to 48 collectors allowing samples to be collected over a 24 hour period. Once all the samples have been collected, the carousel will be transferred to the bench-top assay unit which will perform assays on all of the collected samples, greatly reducing the workload associated with the analysis of the numerous samples collected during a typical epidemiological study. This aerosol sampling and detection apparatus will be integrated with automation technology developed by the Pacific Northwest National Laboratory (PNNL) to produce a self-contained portable personal exposure sampling unit and a bench-top assay unit. Enertechnix will be responsible for the aerosol sampling and microfluidic components and for system integration. PNNL will adapt its automation, power management, and position- and motion- sensing technologies for use in the PEM. The University of Washington (UW) will assist in the implementation of an endotoxin assay employing a miniature colorimetric readout unit developed by FAR Sciences. Prototypes will be developed and, in collaboration with the UW, will be field tested in a variety of environments to demonstrate the performance of the sampler and bench-top assay unit. This system will be the first to provide a highly efficient aerosol to microfluidics interface and the first to provide automated, time- and space-resolved sampling in a portable package. PUBLIC HEALTH RELEVANCE: There is a growing awareness that exposure to environmental contaminants such as fine particulate matter and diesel particulates can trigger or exacerbate diseases such as asthma and cardiovascular disease, but there is still much uncertainty about the importance of specific factors and the relationship between disease and exposure. Asthma affects between 14 and 15 million people in the United States, about 4.8 million of whom are children; its incidence worldwide has doubled in the last 15 years; and it is responsible for 100 million person-days of restricted activity and 5000 deaths per year, amounting to $8.1 billion in direct health related costs. Endotoxin, a ubiquitous component of gram-negative bacteria, is an important bioactive environmental factor that can induce asthma symptoms: bronchoconstriction, airways inflammation and airways hyper-responsiveness. Endotoxin levels, which are known to be highly variable in space and time, have been correlated with asthma symptoms and disease severity. The proposed project will develop an improved personal exposure monitor that can be used to obtain space- and time-resolved measurements of endotoxin contained in airborne particles in a portable device that can be used in studies to develop a better understanding of the relationships between exposure and human health impacts.