Human Subject Age and Activity Level

Tb, Martonen; Rc, Graham; Hofmann, Werner

doi:10.1097/00004032-198907001-00006

Cited by 33 publications

(5 citation statements)

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“…The calculations on numbers of deposited fungal particles presented here apply to adult humans. Alveolar deposition is lower in children's respiratory system, whereas tracheobronchial deposition higher than for adults' (Martonen et al, 1989). Figure 5 shows respiratory deposition's dependence on breathing pattern as reported earlier, e.g., by Vincent (1990).…”

Section: Respiratory Depositionsupporting

confidence: 65%

Aerodynamic Diameters and Respiratory Deposition Estimates of Viable Fungal Particles in Mold Problem Dwellings

Reponen

1995

Aerosol Science and Technology

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The aerodynamic size distributions of particles of major fungal genera or groups, i.e., Penicillium, Cladosporium, Aspergillus, and yeasts, were studied in real exposure situations in mold problem and reference dwellings. A new calculation method was used to estimate respiratory deposition of fungal particles on the basis of the measured data. The major fungal genera had their maximum concentrations in the size range 2.1-3.3 pm, where alveolar deposition for particles > 0.5 p m also has a maximum. According to respiratory deposition calculations for the most obvious breathing patterns in the home environment, 30%-50% of fungal particles would he deposited in the nose and 30%-40% in the alveoli during nasal breathing, whereas 70% would be deposited in the alveoli during oral breathing. More Aspergillus species spores were estimated to deposit in the alveoli for occupants of mold problem versus reference dwellings whereas for yeasts the situation was reversed. Comparison of airborne fungal particle concentrations and numbers of deposited particles between mold problem and reference dwellings indicated that more accurate estimation of exposure to fungal particles is possible if one considers both particle concentration and size.

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Section: Respiratory Depositionsupporting

confidence: 65%

Aerodynamic Diameters and Respiratory Deposition Estimates of Viable Fungal Particles in Mold Problem Dwellings

Reponen

1995

Aerosol Science and Technology

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“…The ventilatory parameters used in our simulations are presented in Table 1. The respiratory intensities are physiologically realistic and correspond to a range of physical states (Martonen et al, 1989).…”

Section: Respiratory Intensitymentioning

confidence: 99%

Effects of Carinal Ridge Shapes on Lung Airstreams

Martonen

Yang

Xue

1994

Aerosol Science and Technology

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Experimental tests cited herein have established that the deposits of inhaled particles may be highly concentrated at carinal ridges within lung bifurcations. Airway cells located at these sites will receive relatively massive doses of toxic substances and pharmacologic drugs. The deposition patterns, therefore, have immediate implications to risk assessment programs and aerosol therapy protocols. Herein, the software FIDAP was employed to study the effects of carinal ridge shapes upon fluid dynamics patterns. A series of welldefined geometric shapes (symmetric and asymmetric) were examined. For each case, a wide range of physiologically realistic flows were considered which corre-sponded to respiratory intensities for sedentary, light, and heavy activities. The results varied in a systematic manner. For example, at the lowest inspiratory flow rate of 14 L/min the effects were highly localized for all carinal ridge shapes, whereas at the highest inspiratory flow rate of 120 L/min the effects were propagated (i.e., to varying degrees) to distal regions. By relating fluid dynamics patterns to particle behavior, the results have inhalation toxicology and aerosol therapy relevance because, for example, bronchogenic carcinomas are selectively distributed within the tracheobronchial tree and certain receptors are known to be preferentially located at airway dividing sites.

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“…This includes determining the very mode of respiration (i.e., oral or nasal) and the mechanics of ventilation as defined, for example, by tidal volume and frequency. 4 Herein, we shall discuss the roles of these three factors with specific references to selected experimental data measuring particle deposition patterns in human subjects.…”

mentioning

confidence: 99%