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The generation of diesel exhaust particle aerosols from a bulk source in an aerodynamic size range similar to atmospheric particles.

Cooney DJ, Hickey AJ - Int J Nanomedicine (2008)

Bottom Line: Inertial impaction data indicated that the particle size distributions of the generated aerosols were trimodal, with count median aerodynamic diameters less than 100 nm.Scanning electron microscopy of deposited particles showed tightly aggregated particles, as would be expected from an evaporative process.Chemical analysis indicated that there were no major changes in the mass proportion of 2 specific aromatic hydrocarbons (benzo[a]pyrene and benzo[k]fluoranthene) in the particles resulting from the aerosolization process.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomedical Engineering, University of North Carolina, Chapel Hill, NC, USA. cooneyinsf@gmail.com

ABSTRACT
The influence of diesel exhaust particles (DEP) on the lungs and heart is currently a topic of great interest in inhalation toxicology. Epidemiological data and animal studies have implicated airborne particulate matter and DEP in increased morbidity and mortality due to a number of cardiopulmonary diseases including asthma, chronic obstructive pulmonary disorder, and lung cancer. The pathogeneses of these diseases are being studied using animal models and cell culture techniques. Real-time exposures to freshly combusted diesel fuel are complex and require significant infrastructure including engine operations, dilution air, and monitoring and control of gases. A method of generating DEP aerosols from a bulk source in an aerodynamic size range similar to atmospheric DEP would be a desirable and useful alternative. Metered dose inhaler technology was adopted to generate aerosols from suspensions of DEP in the propellant hydrofluoroalkane 134a. Inertial impaction data indicated that the particle size distributions of the generated aerosols were trimodal, with count median aerodynamic diameters less than 100 nm. Scanning electron microscopy of deposited particles showed tightly aggregated particles, as would be expected from an evaporative process. Chemical analysis indicated that there were no major changes in the mass proportion of 2 specific aromatic hydrocarbons (benzo[a]pyrene and benzo[k]fluoranthene) in the particles resulting from the aerosolization process.

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Percentage of expected total diesel exhaust particle dose deposited per actuation in actuator, sampling inlet, and nonviable cascade impactor (a) without and (b) with the spacer (mean ± SD, n = 3).Note: *Actuator and inlet deposition were not calculated when the spacer was used.
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f1-ijn-3-435: Percentage of expected total diesel exhaust particle dose deposited per actuation in actuator, sampling inlet, and nonviable cascade impactor (a) without and (b) with the spacer (mean ± SD, n = 3).Note: *Actuator and inlet deposition were not calculated when the spacer was used.

Mentions: DEP deposition on each stage of the NVCI, the sampling inlet, and the actuator, as percentages of total expected dose for each suspension concentration is shown in Figure 1a. The deposition patterns in the NVCI were similar among the concentrations, with a slight increase in the deposited fraction in the middle size range (stages 3 and 4, 1.8–5.0 μm) and a decrease in deposited fraction in the smaller size range (stages 6 and 7, 0.3–1.0 μm) as suspension concentration increased. The proportion of particle mass deposited in the inlet was much greater for the 5.0 mg/g suspension than for the 0.2 or 1.0 mg/g suspensions. This may be explained by a higher proportion of large particles impacting in the back of the inlet for the 5.0 mg/g suspension.


The generation of diesel exhaust particle aerosols from a bulk source in an aerodynamic size range similar to atmospheric particles.

Cooney DJ, Hickey AJ - Int J Nanomedicine (2008)

Percentage of expected total diesel exhaust particle dose deposited per actuation in actuator, sampling inlet, and nonviable cascade impactor (a) without and (b) with the spacer (mean ± SD, n = 3).Note: *Actuator and inlet deposition were not calculated when the spacer was used.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2636590&req=5

f1-ijn-3-435: Percentage of expected total diesel exhaust particle dose deposited per actuation in actuator, sampling inlet, and nonviable cascade impactor (a) without and (b) with the spacer (mean ± SD, n = 3).Note: *Actuator and inlet deposition were not calculated when the spacer was used.
Mentions: DEP deposition on each stage of the NVCI, the sampling inlet, and the actuator, as percentages of total expected dose for each suspension concentration is shown in Figure 1a. The deposition patterns in the NVCI were similar among the concentrations, with a slight increase in the deposited fraction in the middle size range (stages 3 and 4, 1.8–5.0 μm) and a decrease in deposited fraction in the smaller size range (stages 6 and 7, 0.3–1.0 μm) as suspension concentration increased. The proportion of particle mass deposited in the inlet was much greater for the 5.0 mg/g suspension than for the 0.2 or 1.0 mg/g suspensions. This may be explained by a higher proportion of large particles impacting in the back of the inlet for the 5.0 mg/g suspension.

Bottom Line: Inertial impaction data indicated that the particle size distributions of the generated aerosols were trimodal, with count median aerodynamic diameters less than 100 nm.Scanning electron microscopy of deposited particles showed tightly aggregated particles, as would be expected from an evaporative process.Chemical analysis indicated that there were no major changes in the mass proportion of 2 specific aromatic hydrocarbons (benzo[a]pyrene and benzo[k]fluoranthene) in the particles resulting from the aerosolization process.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomedical Engineering, University of North Carolina, Chapel Hill, NC, USA. cooneyinsf@gmail.com

ABSTRACT
The influence of diesel exhaust particles (DEP) on the lungs and heart is currently a topic of great interest in inhalation toxicology. Epidemiological data and animal studies have implicated airborne particulate matter and DEP in increased morbidity and mortality due to a number of cardiopulmonary diseases including asthma, chronic obstructive pulmonary disorder, and lung cancer. The pathogeneses of these diseases are being studied using animal models and cell culture techniques. Real-time exposures to freshly combusted diesel fuel are complex and require significant infrastructure including engine operations, dilution air, and monitoring and control of gases. A method of generating DEP aerosols from a bulk source in an aerodynamic size range similar to atmospheric DEP would be a desirable and useful alternative. Metered dose inhaler technology was adopted to generate aerosols from suspensions of DEP in the propellant hydrofluoroalkane 134a. Inertial impaction data indicated that the particle size distributions of the generated aerosols were trimodal, with count median aerodynamic diameters less than 100 nm. Scanning electron microscopy of deposited particles showed tightly aggregated particles, as would be expected from an evaporative process. Chemical analysis indicated that there were no major changes in the mass proportion of 2 specific aromatic hydrocarbons (benzo[a]pyrene and benzo[k]fluoranthene) in the particles resulting from the aerosolization process.

Show MeSH
Related in: MedlinePlus