Evaluation of PM_2.5 Exposure Contribution Using a Microenvironmental Model

Abstract

Background: Since people move through microenvironments rather than staying in one place, they may be exposed to both indoor and outdoor PM 2.5 concentrations. Objectives:The aim of this study was to assess the exposure level of each sub-population group and evaluate the contribution rate of the major microenvironments.Methods: Exposure scenarios for sub-population groups were constructed on the basis of a 2019 Time-Use survey and the previous literature. A total of five population groups were classified and researchers wearing MicroPEM simulated monitoring PM 2.5 exposure concentrations in real-time over three days. The exposure contribution for each microenvironment were evaluated by multiplying the inhalation rate and the PM 2.5 exposure concentration levels.Results: Mean PM 2.5 concentrations were 33.0 µg/m 3 and 22.5 µg/m 3 in Guro-gu and Wonju, respectively.When the exposure was calculated considering each inhalation rate and concentration, the home showed the highest exposure contribution rate for PM 2.5 . As for preschool children, it was 90.8% in Guro-gu, 94.1% in Wonju. For students it was 65.3% and 67.3%. For housewives it was 98.2% and 95.8%, and 59.5% and 91.7% for office workers. Both regions had higher exposure to PM 2.5 among the elderly compared to other populations, and their PM 2.5 exposure contribution rates were 98.3% and 94.1% at home for Guro-gu and Wonju, respectively. Conclusions:The exposure contribution rate could be dependent on time spent in microenvironments.Notably, the contribution rate of exposure to PM 2.5 at home was the highest because most people spend the longest time at home. Therefore, microenvironments such as home with a higher contribution rate of exposure to PM 2.5 could be managed to upgrade public health.