On the relationship between experimental data for total deposition and model calculations—Part I: Effect of instrumental dead space

Gebhart, J.; Schiller-Scotland, Ch.F.; Egan, Mike; Nixon, W. C. W.

doi:10.1016/0021-8502(89)90039-6

Cited by 12 publications

(7 citation statements)

References 17 publications

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“…(31) The calculated DF was corrected for particle losses in the instrument between inhaled and exhaled sampling points and for mouthpiece dead space. (34,35) Estimations of the surface area and mass of the deposited particles were based on the measured mobility number size distribution and measurements of the particle effective densities, according to principles previously outlined by Löndahl et al (22) and Rissler et al (23) Characterization of the effective density was carried out by an aerosol particle mass analyzer (APM, model 3600, Kanomax, Japan) as described by McMurry et al (36) and more specifically by Rissler et al (37) Based on these data, particles < 60 nm in diameter were assumed to have a near spherical shape and a particle effective density of *1.2 g cm -3 . Particles larger than 60 nm were of agglomerate shape, and thus the density decreased with increasing size.…”

Section: Deposition Fraction and Dose Ratementioning

confidence: 98%

Respiratory Tract Deposition of Inhaled Wood Smoke Particles in Healthy Volunteers

Muala

Nicklasson

Boman

et al. 2015

Journal of Aerosol Medicine and Pulmonary Drug Delivery

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The DF of the investigated sooty wood smoke particles was higher than for previously investigated particles generated during more efficient combustion of biomass. Together with toxicological studies, which have indicated that incomplete biomass combustion particles rich in soot and polycyclic aromatic hydrocarbons (PAHs) are especially harmful, these data highlight the health risks of inadequate wood combustion.

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Section: Deposition Fraction and Dose Ratementioning

confidence: 98%

Respiratory Tract Deposition of Inhaled Wood Smoke Particles in Healthy Volunteers

Muala

Nicklasson

Boman

et al. 2015

Journal of Aerosol Medicine and Pulmonary Drug Delivery

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“…To estimate the true size-resolved deposited fraction (DF(d me )), corrections to DF meas were made for (i) instrumental particle losses, DF equip , (Löndahl et al, 2006), and (ii) instrumental dead space, V D , (Gebhart et al, 1989;Löndahl et al, 2007). These corrections were made individually for each subject and each session as they depend on the breathing pattern according to…”

Section: Particle Respiratory Tract Deposition Measurementsmentioning

confidence: 99%

Experimental determination of deposition of diesel exhaust particles in the human respiratory tract

Rissler

Swietlicki

Bengtsson

et al. 2012

Journal of Aerosol Science

128

104

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a b s t r a c tDiesel emissions are a major contributor to combustion-generated airborne ambient particles. To understand the role of diesel particulate emissions on health effects, it is important to predict the actual particulate dose deposited in the human respiratory tract, with respect to number, surface area and mass. This is complicated by the agglomerate nature of some of these particles. In this study the respiratory tract deposition fraction in the size range 10-500 nm, was determined for 10 healthy volunteers during both idling and transient engine running conditions of a heavy duty diesel engine. The aerosol was characterized with respect to both chemical and physical properties including size resolved particle effective density. The dominating part of the emitted particles had an agglomerate structure. For those formed during transient running conditions, the relationship between particle mass and mobility diameter could be described by a power law function. This was not the case during idling, most likely because of volatile compounds condensing on the agglomerates. The respiratory tract particle deposition revealed large intra-subject variability with some subjects receiving a dose that was twice as high as that of others, when exposed to the same particle concentration. Associations were found between total deposited fractions (TDF), and breathing pattern. There was a difference between the idling and transient cycle with TDF being higher with respect to number during idling. The measured size-dependent deposition fraction of the agglomerated exhaust particles from both running conditions was nearly identical and closely resembled that of spherical hydrophobic particles, if plotted as a function of mobility diameter. Thus, for the size range covered, the mobility diameter could well describe the diameter-dependent particle respiratory tract deposition probability, regardless of the agglomeration state of the particles. Whilst mobility diameter well describes the deposition fraction, more information about particle characteristics is needed to convert this to volume equivalent diameter or estimate dose with respect to surface area or mass. A methodology is presented and applied to calculate deposited dose by surface area and mass of agglomerated particles. The methodology may be useful in similar studies estimating dose to the lung, deposition onto cell cultures and in animal studies.

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“…Because of this the DF was adjusted positively with a magnitude of 0.09 ± 0.03 at 20 nm and less than 0.01 for particles above 50 nm in diameter. Also, a modification was made for the "dead volume" in the mouthpiece, which was 18 cm 3 , and 31 cm 3 where the smaller was used during relaxed breathing (Gebhart et al, 1989). The corrections were made for each subject depending on individual breathing flow and measured temperature.…”

Section: Calculationsmentioning

confidence: 99%

Size-Resolved Respiratory-Tract Deposition of Fine and Ultrafine Hydrophobic and Hygroscopic Aerosol Particles During Rest and Exercise

Löndahl

Maßling

Pagels

et al. 2007

Inhalation Toxicology

196

127

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Airborne ultrafine particles (diameter <100 nm) are ubiquitous in the environment and have been associated with adverse health effects. The respiratory-tract deposition of these particles is fundamentally influenced by their hygroscopicity: their ability to grow by condensation of water in the humid respiratory system. Ambient particles are typically hygroscopic, to varying degrees. This article investigates the influence of hygroscopicity, exercise level, gender, and intersubject variability on size-dependent deposition of fine and ultrafine particles during spontaneous breathing. Using a novel and well-characterized setup, respiratory-tract deposition in the range 12-320 nm has been measured for 29 healthy adults (20 men, 9 women). Each subject completed four sessions: rest and light exercise on an ergometer bicycle while inhaling both hydrophobic (diethylhexylsebacate) and hygroscopic (NaCl) particles. The deposited fraction (DF) based on dry diameters was two to four times higher for the hydrophobic ultrafine particles than for the hygroscopic. The DF of hygroscopic ultrafine particles could be estimated by calculating their equilibrium size at 99.5% relative humidity. The differences in average DF due to exercise level and gender were essentially less than 0.03. However, the minute ventilation increased fourfold during exercise and was 18-46% higher for the men than for the women. Consequently the deposited dose of particles was fourfold higher during exercise and considerably increased for the male subjects. Some individuals consistently had a high DF in all four sessions. As an example, the results show that an average person exposed to 100-nm hydrophobic particles during exercise will receive a 16 times higher dose than a relaxed person exposed to an equal amount of hygroscopic (NaCl) particles.

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On the relationship between experimental data for total deposition and model calculations—Part I: Effect of instrumental dead space

Cited by 12 publications

References 17 publications

Respiratory Tract Deposition of Inhaled Wood Smoke Particles in Healthy Volunteers

Respiratory Tract Deposition of Inhaled Wood Smoke Particles in Healthy Volunteers

Experimental determination of deposition of diesel exhaust particles in the human respiratory tract

Size-Resolved Respiratory-Tract Deposition of Fine and Ultrafine Hydrophobic and Hygroscopic Aerosol Particles During Rest and Exercise

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