The Inequity of Pm2.5 Exposure between Urban and Rural Residents Highly Depends on the Activity Patterns

Abstract

PM2.5 pollution variations in different microenvironments would result in PM2.5 exposure inequity between rural and urban residents. In this study, the real-time PM2.5 exposure of urban and rural residents in China were examined based on portable PM2.5 sensors together with activity patterns derived from questionnaire surveys, with the foci on students and senior citizens who are sensitive to air pollution. The results showed that PM2.5 exposure varied significantly among different resident groups, with the highest among rural students during holidays (61.96 ± 55.02 μg/m3), and the lowest among urban senior citizens (24.43 ± 12.35 μg/m3). PM2.5 exposure peaks mostly occurred during (accompanied) cooking activities owing to strong emissions. Sleeping and resting were main activities that affect PM2.5 exposures of different resident groups, accounting for 60.7~94.5% of total daily exposures. Furthermore, sleeping contributed predominately to PM2.5 exposure inequity between rural and urban residents. This study firstly quantified the PM2.5 exposure inequality based on a novel method and can provide useful information for further studies on the exposure inequity.

Keywords: PM2.5 exposure, Environmental inequity, Activity pattern, Urban and rural difference