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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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Related in: MedlinePlus

Number of particles deposited per actuation on each stage of the electronic low pressure impactor (a) without and (b) with the spacer (mean ± SD, n = 5).
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f3-ijn-3-435: Number of particles deposited per actuation on each stage of the electronic low pressure impactor (a) without and (b) with the spacer (mean ± SD, n = 5).

Mentions: The number of particles that deposited per actuation on each stage of the ELPI for each formulation with and without use of the spacer is shown in Figure 3. The pattern of deposition, like for mass deposition in the NVCI, is similar for all the formulations. For each formulation, the largest number of particles deposited on the filter stage (7–25 nm), with a general trend of decreasing particle deposition in the higher stages. The use of the spacer decreased the average number and standard deviation of particles counted per actuation on each stage for all formulations. These decreases in deposition may have been due to collection of particles in the spacer, particularly in the flow transition regions. Although if spacer deposition did occur, it was either limited to smaller particles that did not constitute much of the particle mass (not seen in the NVCI data) or was confounded with the change in deposition in the inlet. The mass deposited in the NVCI was lower for 0.2 mg/g, approximately the same for 1.0 mg/g, and higher for 5.0 mg/g with the addition of the spacer. It was not easy to discern if the decreases in deposition in the ELPI were dependant on particle size because of the large standard deviations in the upper stages.


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)

Number of particles deposited per actuation on each stage of the electronic low pressure impactor (a) without and (b) with the spacer (mean ± SD, n = 5).
© Copyright Policy
Related In: Results  -  Collection

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

f3-ijn-3-435: Number of particles deposited per actuation on each stage of the electronic low pressure impactor (a) without and (b) with the spacer (mean ± SD, n = 5).
Mentions: The number of particles that deposited per actuation on each stage of the ELPI for each formulation with and without use of the spacer is shown in Figure 3. The pattern of deposition, like for mass deposition in the NVCI, is similar for all the formulations. For each formulation, the largest number of particles deposited on the filter stage (7–25 nm), with a general trend of decreasing particle deposition in the higher stages. The use of the spacer decreased the average number and standard deviation of particles counted per actuation on each stage for all formulations. These decreases in deposition may have been due to collection of particles in the spacer, particularly in the flow transition regions. Although if spacer deposition did occur, it was either limited to smaller particles that did not constitute much of the particle mass (not seen in the NVCI data) or was confounded with the change in deposition in the inlet. The mass deposited in the NVCI was lower for 0.2 mg/g, approximately the same for 1.0 mg/g, and higher for 5.0 mg/g with the addition of the spacer. It was not easy to discern if the decreases in deposition in the ELPI were dependant on particle size because of the large standard deviations in the upper stages.

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