Assessment of personal exposure to ambient fine particles (PM2.5) using sulfur as a tracer for adult subjects in Hong Kong
Other conference paper

Epidemiological studies have revealed associations between health effects and outdoor air pollution, the contribution of outdoor pollution to human exposure must be assessed.

We conducted 24-h personal monitoring from thirteen adult subjects (ages 19-57) in Hong Kong for studies of the ambient-generated exposure to PM2.5. Ambient PM2.5 measurements were conducted simultaneously from seven ambient monitoring stations. All samples were subject to PM2.5 mass by gravimetry and 19 elements (Na to Pb) were analyzed using X-Ray Fluorescence.

We found significant higher subject-specific personal-ambient correlations for sulfur (rs = 0.92, p < 0.001) as compared to PM2.5 mass (rs = 0.79, p < 0.001) and other elements (0.06 < rs < 0.86). Mixed-effects models based on personal vs. ambient sulfur regressions yielded an average exposure factor (Fpex) of 0.73 ± 0.03, supports the use of sulfur as a surrogate to estimate ambient-generated exposure to PM2.5 (Ea). Ea accounts for 41-82% and 57-73% of personal PM2.5 exposures by subject and by season, respectively. Ambient concentrations were highly correlated with Ea (R2 β = 0.90, p < 0.001) than total personal exposure (R2 β = 0.58, p < 0.01). Calibration coefficient of 0.78 (95% confidential interval, CI: 0.72-0.84), suggested an attenuation bias of 22% in estimating PM2.5 health effects using ambient central monitoring station measurements.

This study reports for the first time the estimate of ambient-generated exposure in Hong Kong. In good agreement with previous findings, sulfur can be used as a trace for the studies of PM2.5 of ambient origin. Calibration coefficients were less than 1, indicating attenuated health effects when using ambient PM2.5 as the surrogate for true exposures. This study also highlights the importance of Ena (18-59%) of total personal exposure. Therefore, it is important to treat Ea and Ena as independent predictors of PM2.5-related health effects.
著者Xiao-Cui Chen, Tony J. Ward, Jun-Ji Cao, Shun-Cheng Lee, Judith C Chow, Gabriel NC Lau, Steve H.L. Yim, Kin-Fai Ho
會議名稱Conference of the International Society for Environmental Epidemiology and International Society of Exposure Science-Asia Chapter 2018
會議地點Taipei, Taiwan

上次更新時間 2018-23-10 於 16:41