The effects of intervention with local electrostatic air cleaners on airborne dust and the health of office employees

摘要

The aim of this intervention study was to identify any health improvements in the upper and lower airways of office workers after the installation of local electrostatic air cleaners. Eighty persons with airways symptoms were recruited and randomly assigned to an intervention or control group. Half of the air cleaners had a non-functioning electrostatic unit. Both participants and field researchers were blinded to the group status. Subjective symptoms were recorded using a questionnaire, and indexes calculated for general, irritation and skin symptoms. Objective respiratory health indicators were recorded, with acoustic rhinometry and peak expiratory flow (PEF) meters. In the intervention group there was a decrease in mean dust concentration from 65 to 35 μg/m~3, and a reduction from 57 to 47 μg/m~3 in the control group (P < 0.05 for difference in decline). The reduction was observed for all particles sizes. The irritation and general symptom indices decreased in both groups, but there was no improvement in the intervention group, compared with the control group. Median PEF increased 3 ml/s in the intervention group, and decreased 4 ml/s in the control group. The adjusted odds ratio for an increase above the 70th percentile was 5.7 (95% CI 1.0-32).