Initial Size Distributions and Hygroscopicity of Indoor Combustion Aerosol Particles

Li, Wei; Hopke, Philip K.

doi:10.1080/02786829308959638

Cited by 119 publications

(100 citation statements)

References 18 publications

(17 reference statements)

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“…This is a moderate humidity range, in which the spores remain as singlets and do not aggregate (Reponen et al, 1996). In contrast to the humidity, temperature plays an insignificant role in the hygroscopic growth of the particles (Li and Hopke 1993), therefore room temperature was used for convenience and to represent typical indoor environment…”

Section: Experimental Methodologymentioning

confidence: 99%

Performance assessment of UVAPS: Influence of fungal spore age and air exposure

Kanaani

Hargreaves

Ristovski

et al. 2007

Journal of Aerosol Science

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This work focused on two main outcomes. The first was the assessment of the response of the Ultraviolet Aerodynamic Particle Sizer Spectrometer (UVAPS) for two different fungal spore species.The UVAPS response was investigated as a function of fungal age and the frequency of air current that their colonies exposure to. This outcome was achieved through the measurement of fungal spore fluorescent percentage and fluorescent intensity throughout a period of culturing time (three weeks), and the study of their fluorescent percentage as a function of exposure to air currents. The second objective was to investigate the change of fungal spore size during this period, which may be of use as a co-factor in this differentiation. Fungal spores were released by blowing the surface of the culture colonies with continuous filtered flow air. The UVAPS was used to detect and measure autofluorescing biomolecules such as riboflavin and nicotinamide adenine dinucleotide phosphate (NAD(P)H) present in the released fungal spores.The study demonstrated an increase in aerodynamic diameter for fungal spores under investigation (Aspergillus niger and Penicillium species) over a period of time. The fluorescent percentage of spores was found to decrease for both fungal genera as they aged. It was also found that the fluorescent percentage for tested fungi decreased with frequency of air exposure. The results showed that, while the UVAPS could discriminate between Aspergillus and Penicillium species under well-controlled laboratory conditions, it is unlikely to be able to do so in the field.

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Section: Experimental Methodologymentioning

confidence: 99%

Performance assessment of UVAPS: Influence of fungal spore age and air exposure

Kanaani

Hargreaves

Ristovski

et al. 2007

Journal of Aerosol Science

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“…Moreover, outdoor aerosol composition affects indoor particle concentration and composition (Brauer et al, 1991;Vette et al, 2001;Morawska et al, 2003;Hussein et al, 2006) with stable compounds such as elemental carbon and SO 4 2-favoured over semivolatile polycylic aromatic hydrocarbons and NO 3 -A Talbot et al, Aerosol and Air Quality Research, 17: 653-665, 2017 654 (Huang et al, 2007;Lunden et al, 2008;Poulain et al, 2011;Zhu et al, 2012;Han et al, 2016). In addition, seasonal variability influences outdoor aerosol composition (Poulain et al, 2011;Talbot et al, 2016) which adds further uncertainties to indoor measurements because of the influence of the phase shift of semivolatile species and the water content of hydrophilic particles (Li and Hopke, 1993;Tsai et al, 2012).…”

Section: Introductionmentioning

confidence: 99%

Transformations of Aerosol Particles from an Outdoor to Indoor Environment

Talbot

Kubelová

Makeš

et al. 2017

Aerosol Air Qual. Res.

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Aerosol particle size and chemical composition during summer and winter were investigated in this study. An automated switching valve allowed for indoor and outdoor environments to be sampled near-simultaneously with the same high temporal-resolution instrumentation. During the study, no known indoor sources were present and the sampled room was unoccupied throughout.Accumulation mode indoor/outdoor (I/O) ratios were substantially lower in winter than in summer. This reduction was attributed to particles of outdoor origin shrinking as they entered the warmer and drier indoor environment. An essential factor in this process appeared to be the difference (gradient) between the temperature and relative humidity of the indoor and outdoor environments during the winter. Online aerosol mass spectrometer measurements recorded a 34-38% decrease in I/O ratios for all nonrefractory species during the winter relative to the summer. A similar change in I/O ratios for all species indicated that physical, rather than chemical, processes were responsible.To assess the relative influence of various physical factors on I/O relationships, Spearman rank statistical tests were carried out. These identified wind speed to be negatively correlated to the indoor concentrations for all species. Wind roses incorporating I/O ratios were applied and showed that the wind speed and direction influenced the changes in the indoor composition. The relative outdoor concentration of different aerosol species, steepness of the I/O temperature gradient, and wind speed variability are concluded to be essential factors in I/O aerosol transformations.

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“…The evaporation and condensation model employed for CSPs is based on previous approximations for salts (Ferron 1977;Ferron et al 1988;Hinds 1999), CSPs (Li and Hopke 1993;Robinson and Yu 1998), and multicomponent evaporating liquid droplets in the respiratory tract (Longest and Kleinstreuer 2005). In this model, CSPs are assumed to consist of liquid water, water soluble components, and non-soluble components.…”

Section: Droplet Evaporation and Condensation Modelmentioning

confidence: 99%

“…For example, Li (1993) and Li and Hopke (1993) considered the hygroscopic growth of mainstream and sidestream CSPs at a relative humidity (RH) of approximately 99.5%, which was assumed to represent lung conditions. Li and Hopke (1993) reported an average growth ratio of 1.54 for mainstream CSPs with initial diameters ranging from 0.15-0.40 µm. Sidestream CSPs were shown to grow by an average factor of 1.36 with initial diameters of 0.05-0.350 µm.…”

Section: Introductionmentioning

confidence: 99%

“…To achieve this objective, a computational model of the transport surrounding a CSP is developed based on the approach of Ferron (1977), Yu (1998), and for a multicomponent aerosol consisting of water soluble and insoluble species. The performance of this hygroscopic growth model is compared with the in vitro CSP data of Li and Hopke (1993) and Ishizu et al (1980). The multiple component hygroscopic growth model is then integrated into a CFD particle tracking routine.…”

Section: Introductionmentioning

confidence: 99%

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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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Initial Size Distributions and Hygroscopicity of Indoor Combustion Aerosol Particles

Cited by 119 publications

References 18 publications

Performance assessment of UVAPS: Influence of fungal spore age and air exposure

Performance assessment of UVAPS: Influence of fungal spore age and air exposure

Transformations of Aerosol Particles from an Outdoor to Indoor Environment

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

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