Fine particle concentrators for inhalation exposures—effect of particle size and composition

Sioutas, Constantinos; Koutrakis, Petros; Godleski, John J.; Ferguson, Stephen T.; Kim, Chong S.; Burton, Robert M.

doi:10.1016/s0021-8502(96)00493-4

Cited by 78 publications

(54 citation statements)

References 19 publications

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“…This hypothesis is additionally unlikely because the HAPC has been shown not to distort the ambient size distribution or particle composition during concentration. 2 This is confirmed by our findings (see Figure 3).…”

Section: Discussionsupporting

confidence: 91%

“…The HAPC delivers ambient fine particles (up to 2.5 m in size) concentrated by a factor of ϳ30 times for direct inhalation exposures. 1,2 The optimal size range for concentration in this system is 0.1-2.5 m; ultrafine particles are neither concentrated nor removed, and it is designed not to modify the physicochemical characteristics of the particles. 2 Thus, the HAPC provides a method for the study of increased concentrations of ambient particulate pollution by inhalation in vivo, and it has the capacity to sample concurrently for compositional analysis of particles.…”

Section: Introductionmentioning

confidence: 99%

“…1,2 The optimal size range for concentration in this system is 0.1-2.5 m; ultrafine particles are neither concentrated nor removed, and it is designed not to modify the physicochemical characteristics of the particles. 2 Thus, the HAPC provides a method for the study of increased concentrations of ambient particulate pollution by inhalation in vivo, and it has the capacity to sample concurrently for compositional analysis of particles. The aim of this study is to provide a bioassay of the HAPC and to assess whether passage of particles through the HAPC may alter the biological behavior of a benign particle.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Does the Harvard/U.S. Environmental Protection Agency Ambient Particle Concentrator Change the Toxic Potential of Particles?

Savage

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et al. 2003

Journal of the Air & Waste Management Association

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Section: Discussionsupporting

confidence: 91%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Does the Harvard/U.S. Environmental Protection Agency Ambient Particle Concentrator Change the Toxic Potential of Particles?

Savage

Lawrence

Katz

et al. 2003

Journal of the Air & Waste Management Association

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“…Strengths of the model include the reproducibility of the ischemic insult and the opportunity for use in conscious animals. The Harvard Ambient Particle Concentrator (HAPC) was developed for use in experimental exposure studies to concentrate ambient fine particles (0.1-2.5 µm) by about 30 times without changing their physical properties or chemical composition (Sioutas et al 1995(Sioutas et al , 1997. We have adapted this system for use in studies with awake normal and compromised canine subjects (Godleski et al 2000).…”

mentioning

confidence: 99%

Inhalation of concentrated ambient air particles exacerbates myocardial ischemia in conscious dogs.

Wellenius

Coull

Godleski

et al. 2003

Environ Health Perspect

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Short-term increases in ambient air pollution have been associated with an increased incidence of acute cardiac events. We assessed the effect of inhalation exposure to concentrated ambient particles (CAPs) on myocardial ischemia in a canine model of coronary artery occlusion. Six mongrel dogs underwent thoracotomy for implantation of a vascular occluder around the left anterior descending coronary artery and tracheostomy to facilitate particulate exposure. After recovery (5-13 weeks), pairs of subjects were exposed for 6 hr/day on 3 or 4 consecutive days. Within each pair, one subject was randomly assigned to breathe CAPs on the second exposure day and filtered air at other times. The second subject breathed CAPs on the third exposure day and filtered air at other times. Immediately after each exposure, subjects underwent 5-min coronary artery occlusion. We determined ST-segment elevation, a measure of myocardial ischemia heart rate, and arrhythmia incidence during occlusion from continuous electrocardiograms. Exposure to CAPs (median, 285.7; range, 161.3-957.3 microg/m3) significantly (p = 0.007) enhanced occlusion-induced peak ST-segment elevation in precordial leads V4 (9.4 +/- 1.7 vs. 6.2 +/- 0.9 mm, CAPs vs. filtered air, respectively) and V5 (9.2 +/- 1.3 vs. 7.5 +/- 0.9 mm). ST-segment elevation was significantly correlated with the silicon concentration of the particles and other crustal elements possibly associated with urban street dust (p = 0.003 for Si). No associations were found with CAPs mass or number concentrations. Heart rate was not affected by CAPs exposure. These results suggest that exacerbation of myocardial ischemia during coronary artery occlusion may be an important mechanism of environmentally related acute cardiac events.

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“…The principles by which this concentrator works have been previously described (16,17). A schematic of the concentrator and human exposure chamber is provided (Figure 1).…”

Section: Ambient Aerosol Exposure Systemmentioning

confidence: 99%

Inhalation of PM2.5 does not modulate host defense or immune parameters in blood or lung of normal human subjects.

Harder

Soukup

Ghio

et al. 2001

Environ Health Perspect

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We tested the hypothesis that exposure of healthy volunteers to concentrated ambient air particles (CAPS) between 0.1 and 2.5 microm in diameter is associated with modulation of human alveolar macrophage (AM) function, cytokine production, and immune phenotype in both blood and lung. Thirty-eight volunteers were exposed to either filtered air or CAPS from the immediate environment of the U.S. Environmental Protection Agency human studies facility in Chapel Hill, North Carolina, USA. Particle concentrations in the chamber during the exposures ranged from 23.1 to 311.1 microg/m3. No symptoms were noted by volunteers after the exposure. Eighteen hours after exposure, analysis of cells obtained by bronchoalveolar lavage (BAL) showed a mild increase in neutrophils in both the bronchial (8.4 +/- 2%) and alveolar fractions (4.2 +/- 1.7%) in subjects exposed to the highest concentration of CAPS compared to neutrophils in the fluids of those exposed to filtered air (bronchial fraction 2.7 +/- 0.6%; alveolar fraction 0.8 +/- 0.3%). There was no change in the percentage of lymphocytes or AMs recovered in the lavage after inhalation of the highest particle levels (mean 207 microg/m3). There was also no change in the proportion of lymphocytes in the BAL expressing CD3, CD4, CD8, CD19, nor activation markers CD25 or CD69. Particle inhalation did not affect the expression of CD11b, CD64, CD16, CD14, CD71 on AM, nor was there an effect on phagocytosis or oxidant generation following stimulation with zymosan A. IL-6 and IL-8 levels detected by enzyme-linked immunoabsorbent assay in the BAL were unrelated to inhaled particle levels. The distribution of lymphocyte subsets in blood obtained 18 hr after exposure to CAPS did not differ from that found before exposure. We conclude that ambient air particles are capable of inducing a mild inflammation in the lower respiratory tract but have no effect on immune phenotype or macrophage function under the conditions tested.

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Fine particle concentrators for inhalation exposures—effect of particle size and composition

Cited by 78 publications

References 19 publications

Does the Harvard/U.S. Environmental Protection Agency Ambient Particle Concentrator Change the Toxic Potential of Particles?

Does the Harvard/U.S. Environmental Protection Agency Ambient Particle Concentrator Change the Toxic Potential of Particles?

Inhalation of concentrated ambient air particles exacerbates myocardial ischemia in conscious dogs.

Inhalation of PM2.5 does not modulate host defense or immune parameters in blood or lung of normal human subjects.

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