title: Personal day-time exposure to ultrafine particles in different microenvironments.
abstract: In order to assess the personal exposure to ultrafine particles (UFP) during individual day-time activities and to investigate the impact of different microenvironments on exposure, we measured personal exposure to particle number concentrations (PNC), a surrogate for UFP, among 112 non-smoking participants in Augsburg, Germany over a nearly two-year period from March 2007 to December 2008. We obtained 337 personal PNC measurements from 112 participants together with dairies of their activities and locations. The measurements lasted on average 5.5h and contained on average 330 observations. In addition, ambient PNC were measured at an urban background stationary monitoring site. Personal PNC were highly variable between measurements (IQR of mean: 11780-24650cm(-3)) and also within a single measurement. Outdoor personal PNC in traffic environments were about two times higher than in non-traffic environments. Higher indoor personal PNC were associated with activities like cooking, being in a bistro or exposure to passive smoking. Overall, personal and stationary PNC were weakly to moderately correlated (r<0.41). Personal PNC were much higher than stationary PNC in traffic (ratio: 1.5), when shopping (ratio: 2.4), and indoors with water vapor (ratio: 2.5). Additive mixed models were applied to predict personal PNC by participants' activities and locations. Traffic microenvironments were significant determinants for outdoor personal PNC. Being in a bistro, passive smoking, and cooking contributed significantly to an increased indoor personal PNC.
authors.affiliation: Institute of Epidemiology II, Helmholtz Zentrum München, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany; Environment Science Center, University of Augsburg, Universitätsstr. 1a, 86159 Augsburg, Germany. Electronic address: jianwei.gu@physik.uni-augsburg.de.
authors.forename: Jianwei
authors.initials: J
authors.lastname: Gu
authors.affiliation: Institute of Epidemiology II, Helmholtz Zentrum München, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany.
authors.forename: Ute
authors.initials: U
authors.lastname: Kraus
authors.affiliation: Institute of Epidemiology II, Helmholtz Zentrum München, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Schneider
authors.affiliation: Institute of Epidemiology II, Helmholtz Zentrum München, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany.
authors.forename: Regina
authors.initials: R
authors.lastname: Hampel
authors.affiliation: Bavarian Environment Agency, Bürgermeister-Ulrich-Str. 160, 86179 Augsburg, Germany.
authors.forename: Mike
authors.initials: M
authors.lastname: Pitz
authors.affiliation: Institute of Epidemiology II, Helmholtz Zentrum München, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany.
authors.forename: Susanne
authors.initials: S
authors.lastname: Breitner
authors.affiliation: Institute of Epidemiology II, Helmholtz Zentrum München, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany.
authors.forename: Kathrin
authors.initials: K
authors.lastname: Wolf
authors.affiliation: Department of Environmental Health, National Institute for Health and Welfare, PO Box 95, Kuopio, Finland.
authors.forename: Otto
authors.initials: O
authors.lastname: Hänninen
authors.affiliation: Institute of Epidemiology II, Helmholtz Zentrum München, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany.
authors.forename: Annette
authors.initials: A
authors.lastname: Peters
authors.affiliation: Institute of Epidemiology II, Helmholtz Zentrum München, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany; Environment Science Center, University of Augsburg, Universitätsstr. 1a, 86159 Augsburg, Germany.
authors.forename: Josef
authors.initials: J
authors.lastname: Cyrys
mesh_terms: D000203:Activities of Daily Living; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016902:Air Pollution, Indoor / Q000032:analysis; D003296:Cooking; D004777:Environment; D004781:Environmental Exposure / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods*; D005260:Female; D005858:Germany; D006801:Humans; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D010316:Particle Size; D052638:Particulate Matter / Q000032:analysis* / Q000633:toxicity; D014028:Tobacco Smoke Pollution / Q000032:analysis; D014504:Urban Health; D001335:Vehicle Emissions / Q000032:analysis; D014937:Work
chemical_list: D052638:Particulate Matter; D014028:Tobacco Smoke Pollution; D001335:Vehicle Emissions
keywords: Air pollution; Number concentration; Particulate matter; Personal exposure; Time-activity