Real-time Threshold Exposure Monitor for Particulate Matter and Volatile Organic

描述（由申请人提供）：该第一阶段项目将评估开发PM2.5和PM10尺寸范围内的颗粒物暴露监测器的可行性，以及挥发性有机化合物（VOC）对儿童健康影响的阈值水平。拟议的设备将使用空气动力学颗粒特性进行浓缩和分离到离散尺寸的箱中，并将使用低成本的光学PM传感器来测量低环境颗粒浓度。对采样颗粒质量的实时测量将提供尺寸和时间分辨的暴露数据。该装置还将在微通道收集器中收集采样颗粒，用于随后的实验室分析和每个粒度级的表征。此外，拟议的监测将收集挥发性有机化合物在吸附床预浓缩器。在收集之后，样品将被热解吸并被递送到市售的低成本VOC传感器。预浓缩器的使用将使传感器的检测极限提高至少两个数量级，从而允许检测十亿分之一阈值水平的VOC蒸气。与自动数据记录设备相结合，该监测器将提供低水平环境颗粒物和挥发性有机化合物污染的时间分辨测量。拟议项目的具体目标是：1.演示使用空气动力学透镜气溶胶浓缩器和紧凑型低成本光学灰尘传感器在暴露阈值水平下对环境气溶胶进行实时测量。2.演示使用空气动力学粒度分类器将浓缩的环境气溶胶分为PM2.5和PM10粒度级，并演示使用低成本光学灰尘传感器在健康影响阈值水平下分别测量PM2.5和PM10浓度。3.展示在吸附剂床中预浓缩VOC的能力，选择性地解吸不同挥发性的VOC成分，并使用低成本检测器在健康影响阈值水平下检测这些单独的成分。Enertechnix公司及其在华盛顿大学的合作者将利用其在气溶胶和蒸汽取样和检测方面的丰富经验和专门知识，并利用其广泛的气溶胶仪器和大型气溶胶室，对拟议的接触监测器的每个要素的可行性进行研究。拟议的暴露监测器将为研究人员和监管机构提供一种低成本的设备，可以在儿童健康影响的阈值水平上提供颗粒和VOC暴露的高时间分辨率;它将帮助研究人员调查健康影响和环境暴露之间的联系，并可以作为对颗粒污染敏感的人群或高颗粒危害环境中的工人的警告设备。 公共卫生相关性：暴露于空气中的颗粒物和挥发性有机化合物等环境因素可能引发或加剧哮喘、心血管疾病、癌症和神经系统疾病等疾病，但暴露与疾病之间的因果关系仍有很大的不确定性。因此，目前需要进行研究，以调查环境和工业颗粒物和VOC污染物对人群健康的影响，并采用重量轻、成本低的组件，对颗粒物和VOC进行更好的暴露监测。这种监测器将提供所需的信息，以进一步了解暴露与健康之间的因果关系，并可用于检测在学校，日托设施，家庭，办公室和工业工作场所的颗粒物和挥发性有机化合物的过量水平，表明需要采取补救措施，以消除这些危险的条件。

DESCRIPTION (provided by applicant): This Phase I project will evaluate the feasibility of developing an exposure monitor for particles in the PM2.5 and PM10 size ranges, and for volatile organic compounds (VOCs), at threshold levels for children's health effects. The proposed device will use aerodynamic particle properties for concentration and separation into discrete size bins and will enable the use of low-cost optical PM sensors to measure low ambient particulate concentrations. Real-time measurements of the mass of sampled particles will provide size- and time-resolved exposure data. This device will also collect the sampled particles in micro-channel collectors for subsequent laboratory analysis and characterization of each size fraction. In addition, the proposed monitor will collect VOCs in a sorbent bed preconcentrator. Following collection, the sample will be thermally desorbed and delivered to a commercially available low cost VOC sensor. The use of the preconcentrator will enhance the detection limit of the sensor by at least two orders of magnitude allowing the detection of VOC vapors at parts per billion threshold levels. Coupled to automated data recording equipment, this monitor will provide time- resolved measurements of low level ambient particulate and VOC pollution. The specific aims of the proposed project are to: 1. Demonstrate real-time measurement of ambient aerosols at exposure threshold levels using an aerodynamic lens aerosol concentrator and a compact, low-cost optical dust sensor. 2. Demonstrate classification of concentrated ambient aerosols into PM2.5 and PM10 size fractions using an aerodynamic size classifier, and demonstrate separate measurement of the PM2.5 and PM10 concentrations at health effect threshold levels using low-cost optical dust sensors. 3. Demonstrate the ability to pre-concentrate VOCs in a sorbent bed, to selectively desorb VOC components of differing volatilities, and detect these individual components at health effect threshold levels using a low-cost detector. Building on its extensive experience and expertise in aerosol and vapor sampling and detection, and using its wide array of aerosol instrumentation and its large aerosol chamber, Enertechnix and its collaborators at the University of Washington will investigate the feasibility of each of the elements of the proposed exposure monitor. The proposed exposure monitor will provide researchers and regulators with a low-cost device that can provide high temporal resolution of particulate and VOC exposure at threshold levels for children's health effects; it will aid researchers in investigating the connection between health effects and environmental exposure, and could serve as a warning device for populations sensitive to particle pollution or for workers in environments with high particulate hazards. PUBLIC HEALTH RELEVANCE: Exposure to environmental agents such as airborne particles and volatile organic compounds can trigger or exacerbate diseases such as asthma, cardiovascular disease, cancer, and neurological disorders, but there is still much uncertainty about the causal relationships between exposure and disease. Therefore, there is an ongoing need to conduct studies to investigate the impact of environmental and industrial particulate and VOC contaminants on the health of the population, and for better exposure monitors for particulate and VOCs employing light-weight, low-cost components. Such monitors would provide information required to further our understanding of the causal relationships between exposure and health, and could be used to detect excessive levels of particlate and VOCs in schools, daycare facilities, homes, offices and industrial workplaces, indicating the need for remedial action to eliminate these hazardous conditions.