Limits...
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.

Show MeSH

Related in: MedlinePlus

Particle size distributions by mass of diesel exhaust particle aerosols deposited in the nonviable cascade impactor with and without the spacer (mean, n = 3). Two apparent size modes, Mass Mode 1 (MM1) and Mass Mode 2 (MM2), are labeled.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2636590&req=5

f2-ijn-3-435: Particle size distributions by mass of diesel exhaust particle aerosols deposited in the nonviable cascade impactor with and without the spacer (mean, n = 3). Two apparent size modes, Mass Mode 1 (MM1) and Mass Mode 2 (MM2), are labeled.

Mentions: Similar DEP deposition patterns in the NVCI were observed when the spacer was used (Figure 1b). There was a slight decrease in the mass deposited in the smaller stages for the 0.2 mg/g suspension and an increase in the deposition on most stages for the 5.0 mg/g suspension. When the deposition on each stage is normalized for the width of the particle size range (in logarithms) collected on each stage, creating histograms similar to particle size distributions (Figure 2) these differences can be easily observed. The particle size distributions for each concentration were multimodal with primary maxima <2 μm (Mass Mode 1, MM1) and secondary maxima in the 5–6 μm range (Mass Mode 2, MM2). There were slight variations in the location of the maxima, which are discussed in conjunction with the ELPI data below. The location of these maxima better describe the distributions than estimation of mass median aerodynamic diameter. Calculations of geometric standard deviation could only be performed if the distributions were log-normal with a single mode. Since this was not the case, this calculation was not performed.


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)

Particle size distributions by mass of diesel exhaust particle aerosols deposited in the nonviable cascade impactor with and without the spacer (mean, n = 3). Two apparent size modes, Mass Mode 1 (MM1) and Mass Mode 2 (MM2), are labeled.
© Copyright Policy
Related In: Results  -  Collection

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

f2-ijn-3-435: Particle size distributions by mass of diesel exhaust particle aerosols deposited in the nonviable cascade impactor with and without the spacer (mean, n = 3). Two apparent size modes, Mass Mode 1 (MM1) and Mass Mode 2 (MM2), are labeled.
Mentions: Similar DEP deposition patterns in the NVCI were observed when the spacer was used (Figure 1b). There was a slight decrease in the mass deposited in the smaller stages for the 0.2 mg/g suspension and an increase in the deposition on most stages for the 5.0 mg/g suspension. When the deposition on each stage is normalized for the width of the particle size range (in logarithms) collected on each stage, creating histograms similar to particle size distributions (Figure 2) these differences can be easily observed. The particle size distributions for each concentration were multimodal with primary maxima <2 μm (Mass Mode 1, MM1) and secondary maxima in the 5–6 μm range (Mass Mode 2, MM2). There were slight variations in the location of the maxima, which are discussed in conjunction with the ELPI data below. The location of these maxima better describe the distributions than estimation of mass median aerodynamic diameter. Calculations of geometric standard deviation could only be performed if the distributions were log-normal with a single mode. Since this was not the case, this calculation was not performed.

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