title: Differences in indoor versus outdoor concentrations of ultrafine particles, PM2.5, PMabsorbance and NO2 in Swiss homes.
abstract: Indoor air quality is a growing concern as we spend the majority of time indoors and as new buildings are increasingly airtight for energy saving purposes. For a better understanding of residential indoor air pollution in Switzerland we conducted repeated 1-2-week-long indoor and outdoor measurements of particle number concentrations (PNC), particulate matter (PM), light absorbance of PM2.5 (PMabsorbance) and nitrogen dioxide (NO2). Residents of all homes were enrolled in the Swiss Cohort Study on Air Pollution and Lung and Heart Diseases in Adults (SAPALDIA). Indoor levels were comparable in urban areas and generally low in rural homes. Average indoor levels were 7800 particles/cm(3) (interquartile range=7200); 8.7 μg/m(3) (6.5) PM2.5 and 10.2 μg/m(3) (11.2) NO2. All pollutants showed large variability of indoor/outdoor ratios between sites. We observed similar diurnal patterns for indoor and outdoor PNC. Nevertheless, the correlation of average indoor and outdoor PNC between sites as well as longitudinal indoor/outdoor correlations within sites were low. Our results show that a careful evaluation of home characteristics is needed when estimating indoor exposure to pollutants with outdoor origin.
authors: 1] Swiss Tropical and Public Health Institute, Basel, Switzerland [2] University of Basel, Basel, Switzerland.
authors: Reto
authors: R
authors: Meier
authors: 1] Swiss Tropical and Public Health Institute, Basel, Switzerland [2] University of Basel, Basel, Switzerland.
authors: Marloes
authors: M
authors: Eeftens
authors: 1] Swiss Tropical and Public Health Institute, Basel, Switzerland [2] University of Basel, Basel, Switzerland [3] Centre for Environmental Science and Engineering, Indian Institute of Technology Bombay, Mumbai, India.
authors: Harish C
authors: HC
authors: Phuleria
authors: 1] Swiss Tropical and Public Health Institute, Basel, Switzerland [2] University of Basel, Basel, Switzerland.
authors: Alex
authors: A
authors: Ineichen
authors: 1] Swiss Tropical and Public Health Institute, Basel, Switzerland [2] University of Basel, Basel, Switzerland.
authors: Elisabetta
authors: E
authors: Corradi
authors: 1] Swiss Tropical and Public Health Institute, Basel, Switzerland [2] University of Basel, Basel, Switzerland.
authors: Mark
authors: M
authors: Davey
authors: Institute of Aerosol and Sensor Technology, University of Applied Science Northwestern Switzerland, Windisch, Switzerland.
authors: Martin
authors: M
authors: Fierz
authors: 1] Swiss Tropical and Public Health Institute, Basel, Switzerland [2] University of Basel, Basel, Switzerland.
authors: Regina E
authors: RE
authors: Ducret-Stich
authors: 1] Swiss Tropical and Public Health Institute, Basel, Switzerland [2] University of Basel, Basel, Switzerland.
authors: Inmaculada
authors: I
authors: Aguilera
authors: 1] Swiss Tropical and Public Health Institute, Basel, Switzerland [2] University of Basel, Basel, Switzerland.
authors: Christian
authors: C
authors: Schindler
authors: Division of Pulmonary Medicine, University Hospitals of Geneva, Geneva, Switzerland.
authors: Thierry
authors: T
authors: Rochat
authors: 1] Swiss Tropical and Public Health Institute, Basel, Switzerland [2] University of Basel, Basel, Switzerland.
authors: Nicole
authors: N
authors: Probst-Hensch
authors: 1] Swiss Tropical and Public Health Institute, Basel, Switzerland [2] University of Basel, Basel, Switzerland.
authors: Ming-Yi
authors: MY
authors: Tsai
authors: 1] Swiss Tropical and Public Health Institute, Basel, Switzerland [2] University of Basel, Basel, Switzerland.
authors: Nino
authors: N
authors: Künzli
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D016902:Air Pollution, Indoor / Q000032:analysis*; D015331:Cohort Studies; D004784:Environmental Monitoring / Q000379:methods*; D006798:Housing; D006801:Humans; D016014:Linear Models; D009585:Nitrogen Dioxide / Q000032:analysis*; D010316:Particle Size; D052638:Particulate Matter / Q000032:analysis*; D012424:Rural Population; D012621:Seasons; D013557:Switzerland; D014028:Tobacco Smoke Pollution / Q000032:analysis; D014505:Urban Population
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter; D014028:Tobacco Smoke Pollution; D009585:Nitrogen Dioxide