LAUSR

Background: Given the lack of research on the personal exposure to fine particles (PM2.5) in Hong Kong, we examined the association between short‐term personal exposure to PM2.5 and their constituents and inflammation in exhaled breath in a sample of healthy adult residents. Method: Forty‐six participants underwent personal PM2.5 monitoring for averagely 6 days to obtain 276 samples. Fractional exhaled nitric oxide (FeNO), a biomarker of inflammation in exhaled breath, was measured at the end of each 24‐h personal monitoring. PM2.5 chemical constituents, including organic carbon, elemental carbon, 16 polycyclic aromatic hydrocarbons (PAHs), and 6 phthalate esters, were speciated from the personal samples collected. A mixed‐effects model was used to estimate the association of PM2.5 and their constituents with FeNO. The comparison was also made with parallel analyses using ambient concentrations. Results: Personal exposures to PM2.5 (28.1 ± 23.3 &mgr;g/m3) were higher than the ambient levels (13.3 ± 6.4 &mgr;g/m3) monitored by stations. The composition profile and personal‐to‐ambient concentration ratio varied among subjects with different occupations. An interquartile range (IQR) change in personal exposure to PM2.5 was positively associated with 12.8% increase in FeNO (95% confidence interval, CI: 5.5–20.7%), while nil association was found for ambient PM2.5. Among the constituents measured, only the carcinogenic PAHs were significantly associated with 12% increase in FeNO responses (95% CI, 0.0–25.6%). Conclusion: In conclusion, our study provides the first understanding about personal exposure to PM2.5 and possible sources in Hong Kong. The results also showed that personal exposure to PM2.5 and c‐PAHs were linked to increased FeNO levels among healthy adults. HighlightsPersonal PM2.5 monitoring from 46 healthy adults with up to 6 repeated measurements were conducted.Personal PM2.5 exposures were higher than ambient levels monitored by stations.Mixed‐effects model was applied to assess the relationship between air pollutants exposure and biomarker.Significant associations were observed for the increased FeNO with personal exposure to PM2.5 and c‐PAHs.