Skip to main content

Table 2 Controlled human exposure studies in patients with obstructive airway diseases.

From: Controlled human exposures to ambient pollutant particles in susceptible populations

Study Subject (number) Design Particles Results
Gong et al [26] Healthy volunteers (12)
Patients with mild asthma (12)
Crossover Filtered air, Fine CAPS (174 μg/m3) CAPS induced modest and similar increases in parasympathetic stimulation of HRV in both groups
Gong et al [42] Healthy elderly, age (6)
Elderly patients with COPD (13)
Crossover Filtered air, Fine CAPS (200 μg/m3) Decrease in HRV in healthy elderly but not in COPD patients
Frampton et al [40] Healthy volunteers (40), Patients with asthma (16) Crossover Filtered air
Ultrafine carbon particles (10, 25 and 50 μg/m3)
In healthy subjects, reduced CD54 and CD18 on monocytes; decreased CD18 and CD49d on granulocytes; decreased CD25 in blood monocytes, basophils, and eosinophils; increased lymphocyte expression of CD25.
In asthma, reduced CD11b on monocytes and eosinophils, CD54 on granulocytes, the percentage of CD4+ T cells, basophils, and eosinophils
Piatropaoli et al [41] Healthy volunteers (40), Patients with asthma (16) Crossover Filtered air
Ultrafine carbon particles (10, 25 and 50 μg/m3)
No changes in airway eNO and total cell count/differentials in induced sputum; Increased percentage macrophages in the sputum of asthmatics;
No changes in IL-6 and IL-8 in the sputum
Gong et al [67] Healthy volunteers (4)
Patients with mild asthma (12)
Crossover Filtered air Coarse CAPS (157 μg/m3) Decrease HR and PNN50 4 hours post-exposure
Stenfors et al [43] Healthy volunteers (25)
Patients with mild asthma (15)
Single-blind randomized crossover Filtered air
Diesel exhaust (PM10, 108 μg/m3)
Increased neutrophils, IL-8 and IL-6 in BAL fluid and P-selectin and VCAM-1 in bronchial biopsy, no difference between normal and asthmatics
Gong et al [44] Healthy volunteers (14)
Patients with mild asthma (17)
Crossover Filtered air
Ultrafine CAPS (100 μg/m3 or 145,000/cm3 particle counts
Decreased O2sat, FEV1 and low frequency power; no differences between normal and asthmatics