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Evaluation of human exposure to indoor airborne pollutants: Transport and fate of particulate and gaseous pollutants.

機譯：人體暴露于室內(nèi)空氣污染物的評估：微粒和氣體污染物的運輸和結(jié)局。

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Building environmental conditions such as ventilation and contaminant concentrations are important factors that influence occupant health and comfort. The objective of the present work is to investigate how personal exposure to gaseous and particulate pollutants depends on indoor airflow, source characteristics, and occupant activity in commercial and residential environments.;The study examines airflow and pollutant transport using experimental measurements in conjunction with computational fluid dynamics (CFD). The results demonstrate that breathing has a measurable influence on the airflow in an occupant breathing zone, but it has very small impacts on the occupant thermal plume. The results also show that breathing can significantly affect inhaled particle concentrations, even though the influence varies with source position and particle size. Also, localized hand motions of a sitting manikin do not significantly disrupt the upward thermal plume.;In typical US residences, forced convection driven mixing airflow or buoyancy driven stratified airflow occurs depending on the HVAC fan operation (fan on or fan off, respectively). The measured transition period between mixing flow (fan on) and stratified flow (fan off) is approximately one minute, implying that most airflow in the residence is either dominated by mixing or stratification. A high level of exposure to short-term pollutant sources, such as resuspension of particles from floor surfaces due to human activity, more likely occurs with stratified flow than with highly mixed airflow. This is due to the strong influence of the occupant thermal plume that transports the pollutants into the breathing zone. Furthermore, by transporting air containing ozone across the reactive occupant surface, the occupant thermal plume has a large effect on exposure to ozone reaction products. Due to the reaction of ozone with the skin oils and clothing surfaces, the occupant surface boundary layer becomes depleted of ozone and conversely enriched with ozone reaction products.;The parameter ventilation effectiveness quantifies the effectiveness of airflow distribution and can be used for assessment of exposure to gaseous pollutants. Based on the study results, the usefulness of ventilation effectiveness as an indicator of exposure to particulate pollutants depends on the particle size. For small particles (∼1 microm), an increase of ventilation effectives caused a decrease in occupant exposure, while for large particles (∼7 microm), source location and airflow around the pollutant source are significant factors for the exposure, and the ventilation effectiveness has very little to no effect.
機譯：諸如通風和污染物濃度之類的建筑環(huán)境條件是影響乘員健康和舒適的重要因素。本工作的目的是調(diào)查個人暴露于氣態(tài)和顆粒污染物的方式如何取決于室內(nèi)空氣流量，排放源特征以及商業(yè)和住宅環(huán)境中的乘員活動。該研究使用實驗測量值和計算流體來研究氣流和污染物的傳輸。動態(tài)（CFD）。結(jié)果表明，呼吸對乘員呼吸區(qū)域中的氣流有可測量的影響，但對乘員的熱羽影響很小。結(jié)果還表明，呼吸會顯著影響吸入的顆粒物濃度，即使影響隨源位置和顆粒大小而變化。而且，坐著的人體模型的局部手部動作不會顯著干擾向上的熱羽流。在典型的美國住宅中，取決于HVAC風扇的操作（分別打開或關(guān)閉風扇），會發(fā)生強制對流驅(qū)動的混合氣流或浮力驅(qū)動的分層氣流。 。測得的混合氣流（風扇開啟）和分層氣流（風扇關(guān)閉）之間的過渡時間約為1分鐘，這意味著住宅中的大多數(shù)氣流主要由混合或分層控制。分層氣流比高度混合氣流更容易發(fā)生短期污染物源的大量暴露，例如由于人為活動而使地板表面的顆粒重懸。這是由于乘員的熱羽流的強烈影響，該乘員將污染物輸送到呼吸區(qū)中。此外，通過在反應(yīng)性乘員表面上輸送包含臭氧的空氣，乘員的熱羽對暴露于臭氧反應(yīng)產(chǎn)物具有很大的影響。由于臭氧與皮膚油和衣物表面的反應(yīng)，乘員的表層邊界層中的臭氧被消耗掉，反而富含臭氧反應(yīng)產(chǎn)物。;參數(shù)通風效率量化了氣流分布的有效性，可用于評估暴露程度氣態(tài)污染物。根據(jù)研究結(jié)果，通風效率作為暴露于顆粒污染物的指標的有效性取決于顆粒大小。對于小顆粒（?1微米），通風效率的提高導致乘員暴露的減少，而對于大顆粒（?7微米），污染源周圍的源位置和氣流是暴露的重要因素，通風效率幾乎沒有效果。

著錄項

  • 作者

    Rim, Donghyun.;

  • 作者單位

    The University of Texas at Austin.;

  • 授予單位 The University of Texas at Austin.;
  • 學科 Engineering Civil.;Engineering Environmental.
  • 學位 Ph.D.
  • 年度 2009
  • 頁碼 210 p.
  • 總頁數(shù) 210
  • 原文格式 PDF
  • 正文語種 eng
  • 中圖分類 建筑科學;環(huán)境污染及其防治;
  • 關(guān)鍵詞

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