The effect of cleaning on dust and the health of office workers: an intervention study.

BACKGROUND

Office employees often experience symptoms that could be related to indoor air exposures.

METHODS

In an office building, 114 nonsmokers who had reported mucosal irritation complaints in a survey were selected to participate in a double-blind intervention study. The intervention was carried out in Oslo, Norway, during 1998. The offices of the intervention group were given a comprehensive cleaning, whereas the offices of the control group got a superficial cleaning as a placebo treatment. Dust concentration, health complaints, and nasal congestion were recorded before and after intervention or placebo. In the intervention group, the mean dust concentration was 67 microg/m3 before intervention and 50 microg/m3 after cleaning.

RESULTS

The intervention group reported a reduction in mucosal irritation complaints (a median reduction of 1.0 irritation index points on a scale 0-8) compared with no change in the control group. The odds ratio for reporting a 2-point reduction of the mucosal irritation symptom index was 3.5 (95% confidence interval [CI] = 1.2-9.1) in the intervention group compared with the control group. Nasal congestion, measured by acoustic rhinometry, was also reduced in the intervention group. The odds ratio for reduction in nasal congestion above the 70th percentile was 4.2 (CI = 1.3-11) in the intervention group versus the control group.

CONCLUSIONS

This experimental field trial shows that comprehensive cleaning reduces the airborne dust in offices, and also can reduce mucosal symptoms and nasal congestion.