Introduction: Ambient particulate matter (PM) concentration at ambient air monitoring station was often used as an indicator of population exposure to PM in epidemiological studies. The correlation between personal exposure and ambient concentration of PM varies because of diverse time-activity patterns. The aim of this study was to determine the correlation between personal exposure and ambient concentration of PM10 and PM2.5 with attempts to control impact of time-activity pattern on personal exposure. Personal PM10 and PM2.5 exposures with a fixed time-activity pattern were measured on several times. Methods: Performance of personal environmental monitor (MicroPEM, Model 3.2A, RTI incorporated, USA) was evaluated by co-location of ambient air monitors for PM10 and PM2.5 for 3 days, 12 hours per a day. A field technician carried out personal exposure measurements of PM10 and PM2.5 for 24 hours with a fixed time-activity pattern over 26 days in Seoul, Korea. The time-activity pattern was simulated to a fixed scenario including five microenvironments (office, home, bus, cafeteria, and walking). Ambient PM concentrations were obtained from the closest air monitoring station.Results: The relationship between MicroPEM and central-site monitor had a good linearity. The mean personal and ambient PM10 concentrations were 37.9 ± 31.9 μg/m3 and 72.5 ± 37.9 μg/m3, respectively. The mean personal and ambient PM2.5 concentrations were 28.5 ± 24.1 μg/m3 and 36.1 ± 30.2 μg/m3, respectively. The correlation between personal exposure and ambient concentration for PM2.5 (R2=0.81) was significantly higher than for PM10 (R2=0.44). The personal to ambient ratio of PM2.5 was approximately 1, while the ratio of PM10 was approximately 0.5. The office to ambient ratio of PM2.5 and PM10 were approximately 1 and 0.5, respectively. The finding implied a high infiltration rate of PM2.5 and low infiltration of PM10. The relationship between personal exposure and ambient concentration of PM10 and PM2.5 was different by characteristics of high level episodes. In the Asian dust episode, the personal to ambient ratio of PM10 was 0.2. However, the personal to ambient ratio of PM2.5 approximated 1 during the fine dust advisory episode.Conclusions: Personal exposure and ambient concentrations of PM2.5 were highly correlated with fixed time-activity pattern compared with PM10. The personal to ambient ratio of PM10 was much lower than the ratio of PM2.5. With regards to the Asian dust episode, staying indoors might reduce personal exposure to PM10. However, personal exposure to PM2.5 could not be reduced by staying indoors during the high level episode. It is necessary to manage high ambient PM2.5 concentrations to prevent excessive personal exposure to fine particles.
PDF
download
878987797
028-85220240
