DISTRIBUTION OF OZONE IN INTACT HUMAN LUNGS

臭氧在完整人肺中的分布

• 批准号: 6283051
• 负责人: James S Ultman
• 金额: $ 2.16万
• 依托单位: PENNSYLVANIA STATE UNIV HERSHEY MED CTR
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-12-01 至 1998-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6283051
• 关键词: air pollution; breath tests; chemical reaction; clinical research; computer simulation; human subject; lung imaging /visualization /scanning; mathematical model; morphology; ozone; pulmonary diffusion; pulmonary respiration; respiratory airway volume; respiratory epithelium; spirometry

The National Ambient Air Quality Standard for ozone is based primarily on the evaluation of pulmonary function in individuals exposed to ozone during a couple of hours of moderate physical activity. Decrements in forced expired spirometry parameters observed at ambient levels of ozone were reproducible within subjects, but a significant variation occurred between subjects. We hypothesize that this intersubject variability in response is due in large part to a corresponding variability in ozone uptake into the lower conducting airways, the site most likely responsible for changes in FEV1. To test this hypothesis, we plan to study a group of 30 young male and 30 young female nonsmokers whose anatomy will be characterized by using aciustic reflectometry to measure the volume of the upper airways, and nitrogen dilution to determine the volumes of the lower airways and respiratory airspaces. During each research session, a subject will breathe orally through an apparatus that monitors respired flow and ozone concentration while he or she exercises for one hour at a moderate level. The change in forced expiratory volume, forced vital capacity, and forced expired flow between 25 and 75% of vital capacity will be measured between the beginning and the end of each one hour exercise period. Each subject will participate in three types of research sessions. During the first session, the distribution of ozone uptake will be measured by the bolus inhalation method. During the second session, overall ozone uptake will be measured on a breathe-by-breathe basis while a subject continuously breathes air containing 0.3 ppm O3. During the third session, intended to be a control study, each subject will breathe clean air. The specific aims of this part of the study are to determine: 1) the effect of lung anatomy on the distribution of ozone; 2) the effect of lung anatomy on overall uptake of ozone; 3) the relationship between forced expiratory response and overall ozone uptake; and 4) the relationship between forced expiratory response and regional ozone uptake.

臭氧的国家环境空气质量标准主要基于 关于暴露于臭氧的个体的肺功能的评估 在几个小时的适度体育锻炼中。减少 在环境水平的臭氧水平上观察到的强迫过期的肺活量测定法 在受试者中可重现，但发生了重大差异 在受试者之间。我们假设此对象间的可变性 响应在很大程度上归因于臭氧的相应变异性 吸收较低的导电道，该地点很可能 负责FEV1的变化。为了检验这一假设，我们计划 研究一组30名年轻男性和30名年轻女性非吸烟者 解剖学将通过使用aciustic反射量测量来表征 上呼吸道的体积和氮稀释以确定 下部航空公司和呼吸空间的体积。在每个期间 研究会议，主题将通过设备口服口头 在他或她 练习一个小时，以中等水平。强迫的变化 呼气量，强迫生命力和强迫过期流动 在25％至75％之间，将测量 开始和每个一个小时的运动期结束。每个主题 将参加三种类型的研究课程。在第一个 会话，臭氧摄取的分布将由推注测量 吸入法。在第二届会议期间，总体臭氧吸收将 在呼吸呼吸的基础上进行测量，而受试者不断地测量 呼吸含有0.3 ppm O3的空气。在第三届会议期间 要成为对照研究，每个受试者都会呼吸清洁的空气。这 这一研究的具体目的是确定：1​​）效果 关于臭氧分布的肺解剖学； 2）肺的影响 整体吸收臭氧的解剖学； 3）强迫之间的关系 呼气反应和整体臭氧吸收； 4）关系 在强迫呼气反应和区域臭氧吸收之间。