Biological variability of regional deposition of aerosol particles in the human respiratory tract

Stahlhofen, W.; Gebhart, J.; Heyder, J.

doi:10.1080/15298668191419866

Cited by 97 publications

(26 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The flows given are twice the minute ventilation. Values reported by Stahlhofen et al (1981) are not included because of uncertainties in mouth deposition, but these values tend to fall below those shown.…”

Section: Computed Particle Depositionmentioning

confidence: 99%

Postnatal enlargement of human tracheobronchial airways and implications for particle deposition

et al. 1985

View full text Add to dashboard Cite

In support of predictions for inhaled particle deposition, morphometric measurements were taken on 20 replica airway casts of people aged 11 days to 21 years. Measurements of right upper lobe airway lengths, diameters, and branching angles were made such that a growth model suitable as input to predictive equations for particle deposition efficiency was obtained. The tracheobronchial airways growth was describable by linear regressions on body length. The length-todiameter ratio of growing airways did not change in any simple way as a function of airway generation. Airflow rates for a given state of physical activity for various ages were found from previously published data to be describable by linear regressions on body mass. Three states of physical exertion-low activity, light exertion, and heavy exertion-were used for modeling purposes. The computed particle deposition efficiencies indicate that under most circumstances smaller (younger) people will have greater tracheobronchial deposition efficiencies than larger (older) people. For example, tracheobronchial dose on a per kilogram body mass basis for 5-pmdiameter particles may be more than 6 times higher in the resting newborn than in the resting adult assuming equivalent deposition efficiencies above the larynx.Because little is known regarding age-related differ-(1913) published values for lengths and diameters (sagences in inhaled particle deposition, we have been inter-ittal and frontal) of the trachea and right and left main ested in developing mathematical predictions for particle bronchi for 12 children aged 1 month to 13 years, and a deposition in the tracheobronchial airways correspond-40-year-old adult. Engel's data show relatively rapid but ing to a range of ages. Such predictions are strongly decelerating growth of the measured structures up to dependent on airway anatomy, so measurements of the about age 7 years, but with only one child over age 10 growing airways were taken to develop a model upon years little can be said about growth after age 7. Also, which to base the mathematical predictions for depo-only two generations of airways were well described. sition.Although there is agreement on the sequence of events Although several investigators have provided quanti-during postnatal lung growth, many fundamental questative descriptions of the dimensions of adult human tions remain. There is general agreement (although perairways, few have described the manner in which these haps a lack of direct proof) that the full number of structures grow. Among the earliest morphometric bronchial airways are present at birth and that alveolarmodels for the complete adult tracheobronchial airways ization of bronchioles continues postnatally in a proxiwere those published by Weibel(1963). To generate these mal direction. Bronchial airway growth generally models, measurements from the trachea downward for parallels changes in stature, but there is confusion reabout 10 generations were made on a plastic replica cast garding details. This state of und...

show abstract

Section: Computed Particle Depositionmentioning

confidence: 99%

Postnatal enlargement of human tracheobronchial airways and implications for particle deposition

et al. 1985

View full text Add to dashboard Cite

show abstract

“…A number of in vivo (Walsh et al, 1977;Foord et al, 1978;Chan & Lippmann, 1980;Stahlhofen et al, 1980Stahlhofen et al, , 1981Emmett & Aitken, 1982;Svartengren et al, 1994;Dunbar et al, 2002) and in vitro studies (Cheng et al, 1999(Cheng et al, , 2001Lin et al, 2001;Grgic et al, 2004b;DeHaan & Finlay, 2004;Grgic et al, 2004a;Heenan et al, 2004;Zhang et al, 2007;Zhou et al, 2011;Shinneeb & Pollard, 2012) have been conducted in order to develop an understanding of the flow and particle dynamics in the extrathoracic airways. In vivo experiments are costly and complex to perform, and accurate results are difficult to obtain due to spatial resolution and tissue attenuation limit (Grgic et al, 2004b).…”

Section: Introductionmentioning

confidence: 99%

Direct numerical simulations of flow in realistic mouth–throat geometries

Nicolaou

Zaki

2013

Journal of Aerosol Science

View full text Add to dashboard Cite

show abstract

“…[1][2][3][4][5] Inhalation of PM 10 particulate was studied because of a greater mortality rate during increased levels of air pollution. 6 Toxic particles might affect the human respiratory system because of their physical characteristics.…”

Section: Introductionmentioning

confidence: 99%

Performance Characteristics of PM₁₀ Samplers under Calm Air Conditions

Lai

Chen

2000

Journal of the Air & Waste Management Association

View full text Add to dashboard Cite

The size range of airborne particles that is closely related to specific deposition regions in the human respiratory tract and excess lung burden of these deposited particles is associated with disease. Size-selective sampling, therefore, needs to be performed to assess the related health risks. Performance criteria applied to these samplers must be well characterized in order to provide accurate and reliable results. The PM 10 samplers that have been used in place of the total suspended particulate samplers for the collection of ambient air particles are more relevant to potential inhalation hazards. In order to be certified, a PM 10 sampler must meet reliable performance specifications, primarily the aerosol penetration test with liquid and solid particles in a wind tunnel (wind speeds of 2, 8, and 24 km/hr). This testing is intended to assure reasonable accuracy in aerosol measurements. However, the sampler performance under calm air conditions has not been well studied.In the present study, the sampling heads of three devices-the Harvard impactor, the Personal Environmental Monitor (PEM), and the Sierra Andersen model 241 dichotomous sampler PM 10 inlet head-were tested for aerosol separation efficiency. With the consideration of bias and imprecision of the measurements, five specimens of each type of sampler were chosen for performance testing, repeating the tests 5 times for each specimen. An ultrasonic atomizing nozzle was used to nebulize potassium sodium IMPLICATIONS This work demonstrates that the mean square error (MSE) is a good indicator to show the overall performance of size-selective samplers. The MSE approach provides a clear way to differentiate the inaccuracy from imprecision so that a better sampler can be made. The sampling head of the dichotomous sampler, which is the only PM 10 sizeselective sampling inlet head certified by the U.S. Environmental Protection Agency, has a good fit to the PM 10 criterion, while other samplers have sharper separationcurve slopes and exhibit significant particle bounce when challenged with solid particles.

show abstract

Biological variability of regional deposition of aerosol particles in the human respiratory tract

Cited by 97 publications

References 1 publication

Postnatal enlargement of human tracheobronchial airways and implications for particle deposition

Postnatal enlargement of human tracheobronchial airways and implications for particle deposition

Direct numerical simulations of flow in realistic mouth–throat geometries

Performance Characteristics of PM₁₀ Samplers under Calm Air Conditions

Contact Info

Product

Resources

About

Biological variability of regional deposition of aerosol particles in the human respiratory tract

Cited by 97 publications

References 1 publication

Postnatal enlargement of human tracheobronchial airways and implications for particle deposition

Postnatal enlargement of human tracheobronchial airways and implications for particle deposition

Direct numerical simulations of flow in realistic mouth–throat geometries

Performance Characteristics of PM10 Samplers under Calm Air Conditions

Contact Info

Product

Resources

About

Performance Characteristics of PM₁₀ Samplers under Calm Air Conditions