Personal exposure to fine particles (PM) and respiratory inflammation of common residents in Hong Kong.

BACKGROUND

Given the lack of research on the personal exposure to fine particles (PM) in Hong Kong, we examined the association between short-term personal exposure to PM and their constituents and inflammation in exhaled breath in a sample of healthy adult residents.

METHOD

Forty-six participants underwent personal PM 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. PM 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 PM and their constituents with FeNO. The comparison was also made with parallel analyses using ambient concentrations.

RESULTS

Personal exposures to PM (28.1 ± 23.3 μg/m) were higher than the ambient levels (13.3 ± 6.4 μg/m) 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 PM was positively associated with 12.8% increase in FeNO (95% confidence interval, CI: 5.5-20.7%), while nil association was found for ambient PM. 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 PM and possible sources in Hong Kong. The results also showed that personal exposure to PM and c-PAHs were linked to increased FeNO levels among healthy adults.