How Is Indoor Air Quality during Sleep? A Review of Field Studies

This review aimed to provide an overview of the characterisation indoor air quality (IAQ) during sleeping period, based only on real life conditions’ studies where, at least, one pollutant was considered. Despite consensual complexity air, when focusing environments, available scientific literature is still scarce and falls a multipollutants’ breathed sleep. review, following PRISMA’s approach, identified total 22 that provided insights how IAQ period in conditions. Most focused carbon dioxide (77%), followed by particles (PM2.5, PM10 ultrafines) 18% pollutants such as monoxide, volatile organic compounds formaldehyde. high heterogeneity between (regarding geographical area, type surrounding season year, dwelling, bedrooms’ ventilation, number occupants), several showed exceedances limit values established guidelines or legislation, indicating effort should be made order minimise human exposure pollutants. For instance, considering guideline World Health Organisation 10 µg·m−3 for PM2.5, 86% this registered levels above threshold. Considering people spend third their day sleeping, may have significant impact daily integrated exposure, due higher amount time, even if environment characterised lower pollutants’ levels. Improving current knowledge sleep different settings, well countries, will allow improve accuracy assessments also understand main drivers tackle them.