Would removing indoor air particulates in children's environments reduce rate of absenteeism--a hypothesis.

To conduct a controlled trial to test the ability of a newly developed electrostatic air cleaning technology (EAC) to improve Indoor Air Quality (IAQ) as defined by levels of airborne particles and to investigate the potential to reduce non-attendance rates due to illness among children in two Swedish day care centres. The EAC technology was shown to significantly reduce the indoor particulate load for very fine particles caused by outdoor air pollution by 78% and to reduce the number of fine particles produced indoors by 45%. To test the hypothesis, non-attendance was followed in two centres during 3 years. The EAC technology was in operation during year 2. Non-attendance rates among children in the larger day-care centre decreased by 55%, equalling those levels noted in family-based day care. It is speculated that the air cleaning effect may be due to alterations in electrostatic forces operating within the room enabling fine particulate matter to more easily become and stay airborne. The EAC technology is cost-efficient and might be a way forward to improve IAQ.