Sunday, March 06, 2005

Concentrated Ambient Particles

The particle concentrator gives investigators a chance to observe effects of the particles of composition found in the environment in small groups of people exposed for a short amount of time. In this case, healthy subjects were exposed to small particles at levels ranging above the EPA limit, and 10 fold below the OSHA limit, for two hours. Inflammatory effects were seen, although pathology was not observed. Once again, this is a study powered by concern for community enviromental pollution, the chances of funding for this in the occupational environment is nil.

"Particles were concentrated from the ambient air in Chapel Hill, North Carolina.... Each of 38 subjects was exposed either to filtered air (n = 8) or to CAPs (n = 30) for two hours... For the CAPs-exposed group, the concentration of particulate matter measuring 2.5 microm or less in aerodynamic diameter (PM2.5) in the exposure aerosols varied from 23.1 to 311.1 microg/m3......Subjects exposed to CAPs showed mean increases in fibrinogen of 40 to 48 mg/dL with no obvious differentiation by dose, whereas subjects exposed to filtered air showed no change...... neutrophils showed a dose-dependent increase both when analyzed as an absolute cell count and as a percentage of total lavaged cells. ... We conclude that CAPs induced a modest degree of airway inflammation as judged by lavage, but this effect was not reflected in biopsy tissues from proximal airways. "


Res Rep Health Eff Inst. 2003 Dec;(112):31-50; discussion 51-67.

Health effects of acute exposure to air pollution. Part II: Healthy subjects exposed to concentrated ambient particles.

Holgate ST, Devlin RB, Wilson SJ, Frew AJ.Respiratory Cell and Molecular Biology, Infection, Inflammation and Repair Division, School of Medicine, University of Southampton, Southampton General Hospital, Mail Point B10, Level D, Centre Block, Tremona Road, Southampton SO16 6YD, UK.

The purpose of this study was to assess the impact of short-term exposure to concentrated ambient particles ...

[full text of abstract at pub med]

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