Estimated individual inhaled dose of fine particles and indicators of lung function: A pilot study among Chinese young adults.

Fine particle (PM2.5)-related lung damage has been reported in most studies regarding environmental or personal PM2.5 concentrations. To assess effects of personal PM2.5 exposures on lung function, we recruited 20 postgraduate students and estimated the individual doses of inhaled PM2.5 based on their microenvironmetal PM2.5 concentrations, time-activity patterns and refereed inhalation rates. During the period of seven consecutive days in each of the four seasons, we repeatedly measured the daily lung function parameters and airway inflammation makers such as fractional exhaled nitric oxide (FeNO) as well as systemic inflammation markers including interleukin-1β on the final day. The high individual dose (median (IQR)) of inhaled PM2.5 was 957 (948) μg/day. We observed a maximum FeNO increase (9.1% (95%CI: 2.2-15.5)) at lag 0 day, a maximum decrease of maximum voluntary ventilation (11.8% (95% CI: 4.6-19.0)) at lag 5 day and a maximum interleukin-1β increase (103% (95% CI: 47-159)) at lag 2 day for an interquartile range increase in the individual dose of inhaled PM2.5 during the four seasons. Short-term exposure to PM2.5 assessed by the individual dose of inhaled PM2.5 was associated with higher airway and systemic inflammation and reduced lung function. Further studies are needed to understand better underlying mechanisms of lung damage following acute exposure to PM2.5.