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

描述(申请人提供)：该第一阶段项目将评估开发PM2.5和PM10大小范围内的颗粒物以及挥发性有机化合物(VOCs)暴露监测仪的可行性，该监测仪对儿童健康的影响处于阈值水平。拟议的装置将利用空气动力学颗粒特性进行浓缩和分离到不同大小的垃圾箱中，并将能够使用低成本的光学PM传感器来测量环境中的低颗粒物浓度。对采样颗粒质量的实时测量将提供尺寸和时间分辨率的曝光数据。该装置还将在微通道收集器中收集采样的颗粒，以供随后的实验室分析和表征每个粒度分数。此外，拟议的监测仪将在吸附床预浓缩器中收集VOCs。采集后，样品将被热解吸，并被送往市面上可获得的低成本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，从而能够以十亿分之一的阈值水平检测挥发性有机化合物蒸气。与自动数据记录设备相结合，该监测仪将提供对环境低水平颗粒物和VOC污染的时间分辨率测量。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、低成本的光学粉尘传感器实时测量暴露阈值水平的环境气溶胶。2.演示使用空气动力学尺寸分类器将环境中的浓缩气溶胶分类为PM2.5和PM10大小，并使用低成本的光学粉尘传感器分别测量健康影响阈值水平下的PM2.5和PM10浓度。3.展示在吸附床中预浓缩VOCs的能力，选择性地解吸不同挥发物的VOC组分，并使用低成本检测器在健康影响阈值水平检测这些单独的组分。凭借其在气溶胶和蒸气采样和检测方面的丰富经验和专业知识，并利用其广泛的气溶胶仪器和大型气雾室，Enertech及其在华盛顿大学的合作者将调查拟议的暴露监测器每一个元素的可行性。拟议的暴露监测仪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高时间分辨率的颗粒物和VOC暴露；它将帮助研究人员调查健康影响和环境暴露之间的联系，并可以作为对颗粒物污染敏感的人群或处于高颗粒物危害环境中的工人的警告装置。 公共卫生相关性：暴露在空气颗粒物和挥发性有机化合物等环境因素中会引发或加重哮喘、心血管疾病、癌症和神经疾病等疾病，但暴露与疾病之间的因果关系仍存在很大不确定性。因此，目前有必要进行研究，以调查环境和工业颗粒物和挥发性有机化合物污染物对人口健康的影响，并使用轻质、低成本的部件改进颗粒物和挥发性有机化合物的暴露监测仪。这类监测仪将提供必要的信息，以加深我们对暴露与健康之间因果关系的理解，并可用于检测学校、日托设施、家庭、办公室和工业工作场所中过量的颗粒物和VOCs，表明需要采取补救行动来消除这些危险条件。

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.