PERSONAL SAMPLING OF PARTICLES IN ADULTS - RELATION AMONG PERSONAL, INDOOR, AND OUTDOOR AIR CONCENTRATIONS

To investigate the validity of outdoor particulate matter with a 50% c utoff diameter of 10-mu m (PM10) concentrations as a measure of exposu re in time series studies, the association between personal and outdoo r concentrations, within subjects, over time was investigated, Repeate d measurements of personal, indoor, and outdoor PM10 were-conducted am ong 37 nonsmoking, 50- to 70-year-old adults, living in Amsterdam, Net herlands, 1994, Regression analyses were conducted for each subject se parately, and the distribution of the individual regression and correl ation coefficients was investigated, Furthermore, the extent to which differences among personal, indoor, and outdoor concentrations could b e explained was studied, The median Pearson's R between personal and o utdoor concentrations was 0.50. Excluding days with exposure to enviro nmental tobacco smoke (ETS) improved the correlation to a median R of 0.71, The estimated cross-sectional correlations were lower, 0.34 and 0.50, respectively, Outdoor concentrations (mean, 42 mu g/m(3)) exceed ed indoor concentrations (mean, 35 mu g/m(3)) but underestimated perso nal exposures (mean, 62 mu g/m(3)). The major part of the difference b etween personal and outdoor concentrations could be attributed to expo sure to ETS, living along a busy road, and time spent in a vehicle. Th e results show a reasonably high correlation between personal and outd oor PM P-10 within individuals, providing support for the use of ambie nt PM10 concentrations as a measure of exposure in epidemiologic studi es linking the day-to-day variation in particulate matter air pollutio n to the day-to-day variation in health endpoints such as mortality, h ospital admissions, respiratory symptoms, and lung function.