Abstract/Summary

Insufficient quantity and quality of sleep is a public health concern which can be addressed by interventions for improving sleep outcomes. Environmental factors such as poor air quality are a potential target for intervention, particularly in light of associations between air pollution and worse sleep. The aim of this pilot study was to investigate the effects of using an air purifier on sleep outcomes and mood in 30 healthy adults. There were two conditions (i) air purifier with a High Efficiency Particulate Air (HEPA) filter (ii) air purifier with a placebo filter. Participants undertook both conditions, each over two weeks with a two-week washout, following a counterbalanced, double-blind design. Daily sleep outcomes were measured with actigraphy watches and sleep diaries, whilst daily mood was assessed with the Positive and Negative Affect Schedule. The Insomnia Severity Index, the Pittsburgh Sleep Quality Index, and symptoms of anxiety and depression were measured pre and post. The purifier filter was associated with increased total sleep time for an average of 12 minutes per night and increased total time in bed for an average of 19 minutes per night relative to the placebo. There were several sleep and mood outcomes for which no changes were observed, and time awake after sleep onset was higher for the purifier filter. Air quality was better during the HEPA filter condition. These findings offer positive indications that environmental interventions which improve air quality can have benefits for sleep outcomes in healthy populations who are not exhibiting clinical sleep disturbances.