The active surface of suspended particles as a predictor of lung function and pulmonary symptoms in Austrian school children

At a central elementary school in the capital of Upper Austria children aged 7–10 years underwent repeated respiratory health checkups (questionnaires, diaries, spirometry). Between March and May 2001 the daily means of the signals of a diffusion charging sensor, measuring the “active surface” of suspended particles, and a photoelectric aerosol sensor, measuring the particle-bound polycyclic aromatic hydrocarbons, were related to spirometric results of the total 164 children examined and to the daily symptom scores of a susceptible subgroup. Significant reductions of forced vital capacity (p=0.006) and forced expiratory volume in the first second (p=0.001) and significant increases of wheezing (p=0.001), shortness of breath (p=0.041), cough in the evening (p=0.031) and at night (p=0.018) were found with increase of “active surface” of suspended particles measured at the adjacent outdoor monitoring station, but not with the increase of particle-bound polycyclic aromatic hydrocarbons. Monitoring “active surface” of particles with diameters of about 10 nm–1 μm by means of a diffusion charging sensor might provide additional information in surveillance of particulate matter for prevention of acute effects on respiratory health.