Personal exposure measurements of school-children to fine particulate matter (PM(2.5)) in winter of 2013, Shanghai, China

OBJECTIVE: The aim of this study was to perform an exposure assessment of PM(2.5) (particulate matter less than 2.5μm in aerodynamic diameter) among children and to explore the potential sources of exposure from both indoor and outdoor environments. METHODS: In terms of real-time exposure measurements of PM(2.5), we collected data from 57 children aged 8–12 years (9.64 ± 0.93 years) in two schools in Shanghai, China. Simultaneously, questionnaire surveys and time-activity diaries were used to estimate the environment at home and daily time-activity patterns in order to estimate the exposure dose of PM(2.5) in these children(.) Principle component regression analysis was used to explore the influence of potential sources of PM(2.5) exposure. RESULTS: All the median personal exposure and microenvironment PM(2.5) concentrations greatly exceeded the daily 24-h PM(2.5) Ambient Air Quality Standards of China, the USA, and the World Health Organization (WHO). The median E(total) (the sum of the PM(2.5) exposure levels in different microenvironment and fractional time) of all students was 3014.13 (μg.h)/m(3). The concentration of time-weighted average (TWA) exposure of all students was 137.01 μg/m(3). The median TWA exposure level during the on-campus period (135.81 μg/m(3)) was significantly higher than the off-campus period (115.50 μg/m(3), P = 0.013 < 0.05). Besides ambient air pollution and meteorological conditions, storey height of the classroom and mode of transportation to school were significantly correlated with children’s daily PM(2.5) exposure. CONCLUSIONS: Children in the two selected schools were exposed to high concentrations of PM(2.5) in winter of 2013 in Shanghai. Their personal PM(2.5) exposure was mainly associated with ambient air conditions, storey height of the classroom, and children’s transportation mode to school.