Conditions for measuring supersaturation in the human lung using aerosols

Ferron, G.A.; Haider, B.; Kreyling, Wolfgang G.

doi:10.1016/0021-8502(84)90065-x

Cited by 26 publications

(31 citation statements)

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“…The CSP were assumed to contain, 54 and 6096, water soluble particulate, for sidestream and mainstream CSP, respectively. A relative humidity of 99.5% and a temperature of 37°C was used to simulate conditions in the human respiratory tract (Ferron et al, 1984). Figures 6 and 7 plot growth ratio for different initial sizes.…”

Section: Predictions Of Cigarette Smoke Particle Growth In the Human mentioning

confidence: 99%

“…The partial pressure driving force is then CSP contain water soluble particulate predicted to be 60 and 54% of their mass for mainstream and sidestream CSP, respectively (Li, 1993). Therefore, hygroscopic growth is expected when the CSP enter the subsaturated conditions of the human respiratory tract (99.5%) (Ferron et al, 1984). The extent of this growth can be determined by numerically solving the growth equation which is derived in the following section.…”

Section: Solute Effectmentioning

confidence: 99%

“…1 for CSP growth becomes Equation 14 can be solved numerically. Conditions in the lung (S, T u ) and properties of water vapor (p,, M,, P , , , , , ) are well known (Ferron et al, 1984;Lide, 1996). Properties of CSP (M,, p,, F) are available from current literature and are listed in Table 1 for sidestream CSP and Table 2 for mainstream CSP.…”

Section: Growth Equation For Cigarette Smoke Particlesmentioning

confidence: 99%

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Theoretical Analysis of Hygroscopic Growth Rate of Mainstream and Sidestream Cigarette Smoke Particles in the Human Respiratory Tract

Robinson

1998

Aerosol Science and Technology

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ABSTRACT. The deposition of cigarette smoke particles (CSP) in the human respiratory tract is difficult to predict theoretically due to the uncertainties in the characterization of these particles. Measured deposition efficiencies for CSP do not agree with those for typical particles of similar size. One explanation of this discrepancy is the hygroscopic growth of CSP once inside the respiratory tract. However, a minimum of experimental data exists and no theoretical study was done to explain the hygroscopic nature of CSP. In this paper, hygroscopic growth of mainstream and sidestream CSP is determined theoretically for conditions simulating the human respiratory tract. The hygroscopicity of CSP was found to be significantly less than a salt particle and the resulting growth rates were not large enough to explain the discrepancy between expected and measured deposition efficiencies. AEROSOL SCI-

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Section: Predictions Of Cigarette Smoke Particle Growth In the Human mentioning

confidence: 99%

Section: Solute Effectmentioning

confidence: 99%

Section: Growth Equation For Cigarette Smoke Particlesmentioning

confidence: 99%

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Theoretical Analysis of Hygroscopic Growth Rate of Mainstream and Sidestream Cigarette Smoke Particles in the Human Respiratory Tract

Robinson

1998

Aerosol Science and Technology

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“…• C) to body temperature conditions (37 • C) around the third bifurcation (Ferron et al 1984;McFadden et al 1985;Kaufman and Farahmand 2006). The inclusion of a reduced wall surface temperature in the model will increase the predicted RH values and may further increase the expected growth of CSPs in the MT.…”

Section: Discussionmentioning

confidence: 99%

“…However, it may be possible for RH values to exceed saturation conditions in the upper respiratory tract under certain conditions. For example, Ferron et al (1984) and Sarangapani and Wexler (1996) have shown that supersaturation in the upper respiratory tract can be achieved during the inhalation of cool humid air, based on heat and mass transfer calculations. In a different scenario, supersaturated conditions may also be achieved in the upper respiratory tract through the direct inhalation of cigarette smoke.…”

Section: Introductionmentioning

confidence: 99%

Condensational Growth May Contribute to the Enhanced Deposition of Cigarette Smoke Particles in the Upper Respiratory Tract

Longest

2008

Aerosol Science and Technology

112

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Previous experimental studies have shown that concentrated cigarette smoke particles (CSPs) deposit in the upper airways like much larger 6 to 7 µm aerosols. Based on the frequent assumption that relative humidity (RH) in the lungs does not exceed approximately 99.5%, the hygroscopic growth of initially submicrometer CSPs is expected to be a relatively minor factor. However, the inhalation of mainstream smoke may result in humidity values ranging from sub-saturated through supersaturated conditions. The objective of this study is to evaluate the effect of condensation particle growth on the transport and deposition of CSPs in the upper respiratory tract under various RH and temperature conditions. To achieve this objective, a computational model of transport in the continuous phase surrounding a CSP was developed for a multicomponent aerosol consisting of water soluble and insoluble species. To evaluate the transport and deposition of dilute hygroscopic CSPs in the upper airways, a model of the human mouththroat (MT) through approximately respiratory generation G6 was considered with four steady inhalation conditions. These inhalation conditions were representative of inhaled ambient cigarette smoke as well as warm and hot saturated smoke. Results indicate that RH conditions above 100% are possible in the upper respiratory tract during the inhalation of a warm or hot saturated airstream. For sub-saturated inhalation conditions, initial evaporation of the CSPs was observed followed by hygroscopic growth and diameter increases less than approximately 50%. In contrast, the inhalation of warm or hot saturated air resulted in significant particle growth in the MT and tracheobronchial regions. For the inhalation of warm saturated air 3• C above body temperature, initially 200 and 400 nm particles were observed to increase in size to above 3 µm near the trachea inlet. The upper boundary inhalation condition • C air resulted in 7 to 8 µm droplets entering the trachea. These results do not prove that the enhanced deposition of CSPs in the upper airways is only a result of condensational growth. However, this study does highlight condensational growth as a potentially significant mechanism in the deposition of smoke particles under saturated inhalation conditions. INTRODUCTIONRelationships between cigarette smoke constituents and lung disease, respiratory and systemic cancer, and cardiovascular disease have been well established (Doll and Hill 1950;Wynder and Graham 1950; WHO 2002; U.S. Department of Health and Human Services 2004;. Considering bronchogenic carcinoma, a number of studies have reported evidence linking local sites of deposited cigarette smoke particles (CSPs) with disease formation (Bryson and Spencer 1951;Ermala and Holsti 1955;Martonen 1986;Martonen et al. 1987;Yang et al. 1989). For example, Yang et al. (1989) reported significantly elevated incidents of bronchogenic carcinoma at sites that coincided with previously observed CSP deposition from other studies (Bryson and Spencer 1951;Ermala and Holsti 1...

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Dynamic growth and deposition of hygroscopic aerosols in the nasal airway of a 5‐year‐old child

Kim

Xiuhua

2012

Numer Methods Biomed Eng

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Hygroscopic growth within the human respiratory tract can be significant, which may notably alter the behavior and fate of the inhaled aerosols. The objective of this study is to evaluate the hygroscopic effects upon the transport and deposition of nasally inhaled fine-regime aerosols in children. A physiologically realistic nasal-laryngeal airway model was developed based on magnetic resonance imaging of a 5-year-old boy. Temperature and relative humidity field were simulated using the low Reynolds number k - ε turbulence model and chemical specie transport model under a spectrum of four thermo-humidity conditions. Particle growth and transport were simulated using a well validated Lagrangian tracking model coupled with a user-defined hygroscopic growth module. The subsequent aerosol depositions for the four inhalation scenarios were evaluated on a multiscale basis such as total, subregional, and cellular-level depositions. Results of this study show that a supersaturated humid environment is possible in the nasal turbinate region and can lead to significant condensation growth (d / d(0) > 10) of nasally inhaled aerosols. Depositions in the nasal airway can also be greatly enhanced by condensation growth with appropriate inhalation temperature and humidity. For subsaturated and mild inhalation conditions, the hygroscopic effects were found to be nonsignificant for total depositions, while exerting a large impact upon localized depositions.

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Conditions for measuring supersaturation in the human lung using aerosols

Cited by 26 publications

References 0 publications

Theoretical Analysis of Hygroscopic Growth Rate of Mainstream and Sidestream Cigarette Smoke Particles in the Human Respiratory Tract

Theoretical Analysis of Hygroscopic Growth Rate of Mainstream and Sidestream Cigarette Smoke Particles in the Human Respiratory Tract

Condensational Growth May Contribute to the Enhanced Deposition of Cigarette Smoke Particles in the Upper Respiratory Tract

Dynamic growth and deposition of hygroscopic aerosols in the nasal airway of a 5‐year‐old child

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