Non attendance rates among children in Swedish day care centres before, during and after cleaning the indoor air using an electrostatic air cleaning technology --a controlled trial.

To conduct a controlled trial to test the ability of a newly developed electrostatic air cleaningtechnology (EAC) to improve Indoor Air Quality (IAQ) as defined by levels of air borne particlesand to investigate the potential to reduce non-attendance rates due to illness among children intwo Swedish day care centres. The EAC technology was shown to significantly reduce the indoorparticulate load for very finee particles (>0.3micrometer) caused by outdoor air pollution by 78% and toreduce the number of particles (>3.0micrometer) produced indoors by 45%.Non-attendance was followed for two 'treated" centres and two control centres during threeyears. The EAC technology was in operation during year two. Non-attendance rates amongchildren in the larger day-care centre decreased by 55%, equalling those noted in family based daycare.The EAC technology is cost efficient and might be a way forward to improve IAQ.