Measurement of residents' daily travel air pollution exposure and its mechanism: A case study of suburban communities in Beijing

Abstract

The issue of health has drawn extensive attention from many fields, and environmental pollution exposure is one of the newest hot topics of human mobility and health researches. Using activity- travel diary data of 2010 website- based and GPS- enabled travel survey in Beijing suburban areas(Tiantongyuan and Yizhuang) and air pollution(PM2.5and CO) intensity data within micro travel environment of the same period, this paper measures residents' daily travel air pollution exposure and compares the difference of residents' daily travel air exposure between different groups(gender, age, income, car ownership, etc.) through Analysis of Variance(ANOVA). Furthermore, Structural Equation Model(SEM) was used to explore the mechanism of residents' daily travel air pollution exposure. The results indicate that the mid- income group suffers the highest PM2.5and CO exposure per day, while the highincome group suffers the lowest amount; the tenants experience lower air pollution exposure both at PM2.5and CO than house owners; the unmarried suffer higher level of PM2.5exposure per day than the married; driving license holders expose to higher level of CO exposure per day than those who have no driving license. This offers an insight into health inequity and social justice. To explore the mechanism, we invite the endogenous variables including motorized travel rate, travel duration, travel times, commuting distance, and the exogenous variables such as residents' social- economic attribute. It is found that the motorized travel rate significantly determines the travel duration and times, and the commuting distance is positively correlated with travel duration and times. High motorized travel rate and the commuting distance enhance the air pollution exposure to PM2.5and CO. The exogenous variable of "whether there is a child under 18 at home" contributes positively to residents' daily travel exposure to PM2.5and CO.Car ownership and possession of license card are highly correlated with the motorized travel rate, and further influence the air pollution exposure; residents' income level contributes significantly to PM2.5exposure, and the education level contributes significantly to CO exposure. Research prospects and drawbacks are discussed in the last section. Healthy urban planning and management should be encouraged as well as the guidance of healthy life style, to improve residents' health level and to promote health equity.