Dust Sampling to Simulate the Human Lung

Watson, H. H.

doi:10.1136/oem.10.2.93

Cited by 9 publications

(3 citation statements)

References 4 publications

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“…Irregularly shaped particles such as quartz, clay, and coal have aerodynamic diame ters of spherical particles one half to three quarters of their actual diameter (213). Asbestos fibers greater that 50 }-tm long can penetrate deeply into the lungs of experimental animals (207), almost reaching the alveoli.…”

Section: Effect 0/ Shape and Hygroscopic Propertiesmentioning

confidence: 99%

Defense Mechanisms of the Lungs

Cohen¹,

Gold²

1975

Annu. Rev. Physiol.

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·:·1133Nonviable particles enter the atmosphere from forest fires, wind action on dessicated soil, entrainment of sea spray, volcanic debris, and gas phase reactions. Man-made sources account for approximately 185-415 X 106 metric tons per year out of an estimated total of 985-26 15 X 106 metric tons per year and are generated from less than 1% of the earth's surface (6 1, 83, 195). The size of the particle is the single most important feature of an aerosol because it determines the stability of the aerosol. The largest size, highest concentration, and greatest diversity in source and composition of particles occurs in the troposphere immediately above the surface of the earth. Although size and concentration of particles tend to decrease with altitude (and distance from urban centers), gas phase reactions activated by sunlight generate large numbers of new particles between 1000-3000 ft in the troposphere and 60,000--65,000 ft in the stratosphere (6 1). These reactions involve hydrocarbons and oxides of nitrogen from man-made pollution over cities, yielding complex mixtures of nitrogen dioxide, ozone, formaldehyde, ketones, peroxyacyl nitrates, carbon monoxide, etc (4). Although only 35% of the total weight of the particles in this urban aerosol is in the submicronic range, this size range contains the largest number of particles with the largest surface area. Such small size assures deep penetration into the lung, but also favors adsorption of gas by the particle, thus enhancing its capacity to potentiate reactions to irritant gases by causing a high local concentration (44). Although aerosols inside urban buildings are predominantly smaller in size than aerosols outside buildings and so increase the risk for the occupants, most urban aerosols are monitored only outside buildings 'Annu. Rev. Physiol. 1975.37:325-350. Downloaded from www.annualreviews.org Access provided by Western Michigan University on 02/03/15. For personal use only.Quick links to online content Further ANNUAL REVIEWS

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Section: Effect 0/ Shape and Hygroscopic Propertiesmentioning

confidence: 99%

Defense Mechanisms of the Lungs

Cohen¹,

Gold²

1975

Annu. Rev. Physiol.

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“…According to the published literature, the first approach to simulate the dust particle physical parameters effects on particle transport and deposition (TD) in the upper bronchiole is studied by Watson. 2 A theoretical study investigates aerosol TD in the human bifurcating airways and reports minimum deposition for 0.3 mm diameter particle. 3 The available published studies have adopted different particle tracking methods.…”

Section: Introductionmentioning

confidence: 99%

Euler–Lagrange approach to investigate respiratory anatomical shape effects on aerosol particle transport and deposition

Islam

Saha

Sauret

et al. 2019

Toxicology Research and Application

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An accurate knowledge of the pulmonary aerosol particle transport in the realistic lung is essential to deliver the therapeutic particle to the targeted site of the bifurcating airways. The available in silico studies have enriched the knowledge of the aerosol transport and deposition (TD) in the lung; however, the absolute TD data in the realistic lung airway are still elusive. Therefore, in this study, a 3-D geometry of the human lung central airway is developed from the computed tomography (CT) images. A CT scan-based modified lung geometry with a smooth surface and nonrealistic Weibel’s lung geometry is also generated. The coal mine exhausted aerosol TD in the upper airway is investigated. The Euler–Lagrange (E-L) method for particle tracking and ANSYS Fluent solver are used to carry out the entire investigation. The effective diameter method is employed to define the shape-specific particles and is integrated with the E-L method. The anatomical shape effects on the deposition patterns are investigated for different deposition parameter. The numerical results illustrated that the airway geometry, particle shape, particle diameter, and breathing flow rates significantly influence the aerosol TD pattern in the upper airway. The present study reports that airway tracheal wall is the new deposition hot spot for the CT-based geometry instead of bifurcating area for the idealized model, which might be helpful for zone-specific drug delivery to the respiratory airways.

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“…this flow the unit has ani efficiency versus particle-size curve comparable to that of the upper respiratory system in man (1,2).…”

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confidence: 94%