Quantifying Exhaled Particles in Healthy Humans During Various Respiratory Activities Under Realistic Conditions.

IF 2 4区 医学 Q3 RESPIRATORY SYSTEM
Katharina Schwarz, Nadja Struß, Liudmila Banari, Jens M Hohlfeld
{"title":"Quantifying Exhaled Particles in Healthy Humans During Various Respiratory Activities Under Realistic Conditions.","authors":"Katharina Schwarz, Nadja Struß, Liudmila Banari, Jens M Hohlfeld","doi":"10.1089/jamp.2022.0076","DOIUrl":null,"url":null,"abstract":"<p><p><b><i>Background:</i></b> Quantitatively collecting and characterizing exhaled aerosols is vital for infection risk assessment, but the entire droplet size spectrum has often been neglected. We analyzed particle number and size distribution of healthy participants in various respiratory activities, considering inter-individual variability, and deployed a simplified far-field model to inform on infection risks. <b><i>Methods:</i></b> Participants repeated the same respiratory activities on two visits. Particles were collected using an airtight extraction helmet supplied with High Efficiency Particulate Air (HEPA) filtered air. The sampling volume flow was transported to two particle counters covering the small and large particle spectrum. The applied simple mass balance model included respiratory activity, viral load, room size, and air exchange rates. <b><i>Results:</i></b> Thirty participants completed the study. The major fraction of the number-based size distribution was <5 μm in all respiratory activities. In contrast, the major fraction of the volume-based size distribution was 2-12 μm in tidal breathing, but >60 μm in all other activities. Aerosol volume flow was lowest in tidal breathing, 10-fold higher in quiet/normal speaking, deep breathing, coughing, and 100-fold higher in loud speaking/singing. Intra-individual reproducibility was high. Between participants, aerosol volume flow varied by two orders of magnitude in droplets <80 μm, and three orders of magnitude in droplets >80 μm. Simple model calculations not accounting for potential particle size-dependent differences in viral load and infection-related differences were used to model airborne pathogen concentrations. <b><i>Conclusions:</i></b> Quantitative analysis of exhaled aerosols for the entire droplet size spectrum as well as the variability in aerosol emission between individuals provides information that can support infection research. Clinical Trial Registration number: NCT04771585.</p>","PeriodicalId":14940,"journal":{"name":"Journal of Aerosol Medicine and Pulmonary Drug Delivery","volume":" ","pages":"51-63"},"PeriodicalIF":2.0000,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Aerosol Medicine and Pulmonary Drug Delivery","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1089/jamp.2022.0076","RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2024/1/29 0:00:00","PubModel":"Epub","JCR":"Q3","JCRName":"RESPIRATORY SYSTEM","Score":null,"Total":0}
引用次数: 0

Abstract

Background: Quantitatively collecting and characterizing exhaled aerosols is vital for infection risk assessment, but the entire droplet size spectrum has often been neglected. We analyzed particle number and size distribution of healthy participants in various respiratory activities, considering inter-individual variability, and deployed a simplified far-field model to inform on infection risks. Methods: Participants repeated the same respiratory activities on two visits. Particles were collected using an airtight extraction helmet supplied with High Efficiency Particulate Air (HEPA) filtered air. The sampling volume flow was transported to two particle counters covering the small and large particle spectrum. The applied simple mass balance model included respiratory activity, viral load, room size, and air exchange rates. Results: Thirty participants completed the study. The major fraction of the number-based size distribution was <5 μm in all respiratory activities. In contrast, the major fraction of the volume-based size distribution was 2-12 μm in tidal breathing, but >60 μm in all other activities. Aerosol volume flow was lowest in tidal breathing, 10-fold higher in quiet/normal speaking, deep breathing, coughing, and 100-fold higher in loud speaking/singing. Intra-individual reproducibility was high. Between participants, aerosol volume flow varied by two orders of magnitude in droplets <80 μm, and three orders of magnitude in droplets >80 μm. Simple model calculations not accounting for potential particle size-dependent differences in viral load and infection-related differences were used to model airborne pathogen concentrations. Conclusions: Quantitative analysis of exhaled aerosols for the entire droplet size spectrum as well as the variability in aerosol emission between individuals provides information that can support infection research. Clinical Trial Registration number: NCT04771585.

在真实条件下,量化健康人在各种呼吸活动中的呼出颗粒。
背景:定量收集和描述呼出气溶胶对感染风险评估至关重要,但整个液滴粒径谱往往被忽视。考虑到个体间的差异,我们分析了健康参与者在各种呼吸活动中的微粒数量和大小分布,并部署了一个简化的远场模型,以便为感染风险提供信息。研究方法参与者两次重复相同的呼吸活动。使用密闭抽气头盔收集颗粒物,头盔中的空气经过高效微粒空气过滤器(HEPA)过滤。采样体积流被输送到两个颗粒计数器,涵盖小颗粒和大颗粒频谱。应用的简单质量平衡模型包括呼吸活动、病毒负荷、房间大小和空气交换率。研究结果30 名参与者完成了研究。在所有其他活动中,基于数量的粒度分布的主要部分为 60 μm。潮式呼吸时气溶胶体积流量最低,安静/正常说话、深呼吸和咳嗽时气溶胶体积流量高 10 倍,大声说话/唱歌时气溶胶体积流量高 100 倍。个体间的重现性很高。不同参与者之间,80 μm 微滴的气溶胶体积流量相差两个数量级。在建立空气传播病原体浓度模型时,使用了简单的模型计算,但没有考虑病毒载量和感染相关差异中潜在的颗粒大小依赖性差异。结论对呼出气溶胶的整个液滴粒径谱以及个体间气溶胶排放的差异性进行定量分析,可为感染研究提供信息支持。临床试验注册号:NCT04771585:NCT04771585。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
求助全文
约1分钟内获得全文 求助全文
来源期刊
CiteScore
6.70
自引率
2.90%
发文量
34
审稿时长
>12 weeks
期刊介绍: Journal of Aerosol Medicine and Pulmonary Drug Delivery is the only peer-reviewed journal delivering innovative, authoritative coverage of the health effects of inhaled aerosols and delivery of drugs through the pulmonary system. The Journal is a forum for leading experts, addressing novel topics such as aerosolized chemotherapy, aerosolized vaccines, methods to determine toxicities, and delivery of aerosolized drugs in the intubated patient. Journal of Aerosol Medicine and Pulmonary Drug Delivery coverage includes: Pulmonary drug delivery Airway reactivity and asthma treatment Inhalation of particles and gases in the respiratory tract Toxic effects of inhaled agents Aerosols as tools for studying basic physiologic phenomena.
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信