Peak expiratory flow, breath rate and blood pressure in adults with changes in particulate matter air pollution during the Beijing Olympics: A panel study

Objectives: This study aims to examine whether changes in short-term exposures to particulate matter are associated with changes in lung function, breath rate, and blood pressure among healthy adults and whether smoking status modifies the association. Methods: We took advantage of the artificially controlled changes in air pollution levels that occurred during the 2008 Olympic Games in Beijing, China and conducted a panel study of 201 Beijing residents. Data were collected before, during, and after the Olympics, respectively. Linear mixed-effect models and generalized estimating equation models were used to compare measurements of peak expiratory flow, breath rate and blood pressure across three time points. Results: The mean values of peak expiratory flow were 346.0. L/min, 399.3. L/min, and 364.1. L/min over the three study periods. Peak expiratory flow levels increased in 78% of the participants when comparing the during- with pre- Olympics time points, while peak expiratory flow levels decreased in 80% of participants for the post- and during-Olympic periods comparison. In subgroup analyses comparing the during-Olympic to pre-Olympic time points, we found a larger percentage change in peak expiratory flow (+17%) among female, younger and non-smoking participants than among male, elderly and smoking participants (+12%). The percentage of participants with a fast breath rate (>20/min) changed from 9.7% to 4.9% to 30.1% among females, and from 7.9% to 2.6% to 27.3% among males over the three time points. The changes in blood pressure over the three study periods were not very clear, although there is an increase in diastolic pressure and a decrease in pulse pressure among males during the games. Conclusions: The results suggest that exposure to different air pollution levels has significant effects on respiratory function. Smoking, age and gender appear to modify participants[U+05F3] biological response to changes in air quality.